airflow/www/views.py

#
# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements.  See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership.  The ASF licenses this file
# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance
# with the License.  You may obtain a copy of the License at
#
#   http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing,
# software distributed under the License is distributed on an
# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
# KIND, either express or implied.  See the License for the
# specific language governing permissions and limitations
# under the License.
#
import collections
import copy
import itertools
import json
import logging
import math
import re
import sys
import traceback
import warnings
from bisect import insort_left
from collections import defaultdict
from datetime import datetime, timedelta
from functools import wraps
from json import JSONDecodeError
from operator import itemgetter
from typing import Any, Callable, Dict, List, Optional, Set, Tuple, Union
from urllib.parse import parse_qsl, unquote, urlencode, urlparse

import configupdater
import lazy_object_proxy
import markupsafe
import nvd3
import sqlalchemy as sqla
from croniter import croniter
from flask import (
    Response,
    abort,
    before_render_template,
    flash,
    g,
    make_response,
    redirect,
    render_template,
    request,
    send_from_directory,
    session as flask_session,
    url_for,
)
from flask_appbuilder import BaseView, ModelView, expose
from flask_appbuilder.actions import action
from flask_appbuilder.fieldwidgets import Select2Widget
from flask_appbuilder.models.sqla.filters import BaseFilter
from flask_appbuilder.security.decorators import has_access
from flask_appbuilder.security.views import (
    PermissionModelView,
    PermissionViewModelView,
    ResetMyPasswordView,
    ResetPasswordView,
    RoleModelView,
    UserDBModelView,
    UserInfoEditView,
    UserLDAPModelView,
    UserOAuthModelView,
    UserOIDModelView,
    UserRemoteUserModelView,
    UserStatsChartView,
    ViewMenuModelView,
)
from flask_appbuilder.urltools import get_order_args, get_page_args, get_page_size_args
from flask_appbuilder.widgets import FormWidget
from flask_babel import lazy_gettext
from jinja2.utils import htmlsafe_json_dumps, pformat  # type: ignore
from markupsafe import Markup, escape
from pendulum.datetime import DateTime
from pendulum.parsing.exceptions import ParserError
from pygments import highlight, lexers
from pygments.formatters import HtmlFormatter
from sqlalchemy import Date, and_, desc, func, inspect, union_all
from sqlalchemy.exc import IntegrityError
from sqlalchemy.orm import Session, joinedload
from wtforms import SelectField, validators
from wtforms.validators import InputRequired

import airflow
from airflow import models, plugins_manager, settings
from airflow.api.common.mark_tasks import (
    set_dag_run_state_to_failed,
    set_dag_run_state_to_queued,
    set_dag_run_state_to_success,
    set_state,
)
from airflow.compat.functools import cached_property
from airflow.configuration import AIRFLOW_CONFIG, conf
from airflow.exceptions import AirflowException, ParamValidationError
from airflow.executors.executor_loader import ExecutorLoader
from airflow.jobs.base_job import BaseJob
from airflow.jobs.scheduler_job import SchedulerJob
from airflow.jobs.triggerer_job import TriggererJob
from airflow.models import (
    Connection,
    DagModel,
    DagOwnerAttributes,
    DagTag,
    Log,
    SlaMiss,
    TaskFail,
    XCom,
    errors,
)
from airflow.models.abstractoperator import AbstractOperator
from airflow.models.dag import DAG, get_dataset_triggered_next_run_info
from airflow.models.dagcode import DagCode
from airflow.models.dagrun import DagRun, DagRunType
from airflow.models.dataset import Dataset, DatasetDagRef, DatasetDagRunQueue
from airflow.models.operator import Operator
from airflow.models.serialized_dag import SerializedDagModel
from airflow.models.taskinstance import TaskInstance
from airflow.providers_manager import ProvidersManager
from airflow.security import permissions
from airflow.ti_deps.dep_context import DepContext
from airflow.ti_deps.dependencies_deps import RUNNING_DEPS, SCHEDULER_QUEUED_DEPS
from airflow.timetables.base import DataInterval, TimeRestriction
from airflow.timetables.interval import CronDataIntervalTimetable
from airflow.utils import json as utils_json, timezone, yaml
from airflow.utils.airflow_flask_app import get_airflow_app
from airflow.utils.dates import infer_time_unit, scale_time_units
from airflow.utils.docs import get_doc_url_for_provider, get_docs_url
from airflow.utils.helpers import alchemy_to_dict
from airflow.utils.log import secrets_masker
from airflow.utils.log.log_reader import TaskLogReader
from airflow.utils.net import get_hostname
from airflow.utils.session import NEW_SESSION, create_session, provide_session
from airflow.utils.state import State, TaskInstanceState
from airflow.utils.strings import to_boolean
from airflow.utils.timezone import td_format, utcnow
from airflow.version import version
from airflow.www import auth, utils as wwwutils
from airflow.www.decorators import action_logging, gzipped
from airflow.www.forms import (
    ConnectionForm,
    DagRunEditForm,
    DateTimeForm,
    DateTimeWithNumRunsForm,
    DateTimeWithNumRunsWithDagRunsForm,
    TaskInstanceEditForm,
)
from airflow.www.widgets import AirflowModelListWidget, AirflowVariableShowWidget

PAGE_SIZE = conf.getint('webserver', 'page_size')
FILTER_TAGS_COOKIE = 'tags_filter'
FILTER_STATUS_COOKIE = 'dag_status_filter'
LINECHART_X_AXIS_TICKFORMAT = (
    "function (d, i) { let xLabel;"
    "if (i === undefined) {xLabel = d3.time.format('%H:%M, %d %b %Y')(new Date(parseInt(d)));"
    "} else {xLabel = d3.time.format('%H:%M, %d %b')(new Date(parseInt(d)));} return xLabel;}"
)


def truncate_task_duration(task_duration):
    """
    Cast the task_duration to an int was for optimization for large/huge dags if task_duration > 10s
    otherwise we keep it as a float with 3dp
    """
    return int(task_duration) if task_duration > 10.0 else round(task_duration, 3)


def get_safe_url(url):
    """Given a user-supplied URL, ensure it points to our web server"""
    valid_schemes = ['http', 'https', '']
    valid_netlocs = [request.host, '']

    if not url:
        return url_for('Airflow.index')

    parsed = urlparse(url)

    # If the url contains semicolon, redirect it to homepage to avoid
    # potential XSS. (Similar to https://github.com/python/cpython/pull/24297/files (bpo-42967))
    if ';' in unquote(url):
        return url_for('Airflow.index')

    query = parse_qsl(parsed.query, keep_blank_values=True)

    url = parsed._replace(query=urlencode(query)).geturl()

    if parsed.scheme in valid_schemes and parsed.netloc in valid_netlocs:
        return url

    return url_for('Airflow.index')


def get_date_time_num_runs_dag_runs_form_data(www_request, session, dag):
    """Get Execution Data, Base Date & Number of runs from a Request"""
    date_time = www_request.args.get('execution_date')
    if date_time:
        date_time = _safe_parse_datetime(date_time)
    else:
        date_time = dag.get_latest_execution_date(session=session) or timezone.utcnow()

    base_date = www_request.args.get('base_date')
    if base_date:
        base_date = _safe_parse_datetime(base_date)
    else:
        # The DateTimeField widget truncates milliseconds and would loose
        # the first dag run. Round to next second.
        base_date = (date_time + timedelta(seconds=1)).replace(microsecond=0)

    default_dag_run = conf.getint('webserver', 'default_dag_run_display_number')
    num_runs = www_request.args.get('num_runs', default=default_dag_run, type=int)

    # When base_date has been rounded up because of the DateTimeField widget, we want
    # to use the execution_date as the starting point for our query just to ensure a
    # link targeting a specific dag run actually loads that dag run.  If there are
    # more than num_runs dag runs in the "rounded period" then those dagruns would get
    # loaded and the actual requested run would be excluded by the limit().  Once
    # the user has changed base date to be anything else we want to use that instead.
    query_date = base_date
    if date_time < base_date and date_time + timedelta(seconds=1) >= base_date:
        query_date = date_time

    drs = (
        session.query(DagRun)
        .filter(DagRun.dag_id == dag.dag_id, DagRun.execution_date <= query_date)
        .order_by(desc(DagRun.execution_date))
        .limit(num_runs)
        .all()
    )
    dr_choices = []
    dr_state = None
    for dr in drs:
        dr_choices.append((dr.execution_date.isoformat(), dr.run_id))
        if date_time == dr.execution_date:
            dr_state = dr.state

    # Happens if base_date was changed and the selected dag run is not in result
    if not dr_state and drs:
        dr = drs[0]
        date_time = dr.execution_date
        dr_state = dr.state

    return {
        'dttm': date_time,
        'base_date': base_date,
        'num_runs': num_runs,
        'execution_date': date_time.isoformat(),
        'dr_choices': dr_choices,
        'dr_state': dr_state,
    }


def _safe_parse_datetime(v):
    """Parse datetime and return error message for invalid dates"""
    try:
        return timezone.parse(v)
    except (TypeError, ParserError):
        abort(400, f"Invalid datetime: {v!r}")


def dag_to_grid(dag, dag_runs, session):
    """
    Create a nested dict representation of the DAG's TaskGroup and its children
    used to construct the Graph and Grid views.
    """
    query = (
        session.query(
            TaskInstance.task_id,
            TaskInstance.run_id,
            TaskInstance.state,
            sqla.func.count(sqla.func.coalesce(TaskInstance.state, sqla.literal('no_status'))).label(
                'state_count'
            ),
            sqla.func.min(TaskInstance.start_date).label('start_date'),
            sqla.func.max(TaskInstance.end_date).label('end_date'),
            sqla.func.max(TaskInstance._try_number).label('_try_number'),
        )
        .filter(
            TaskInstance.dag_id == dag.dag_id,
            TaskInstance.run_id.in_([dag_run.run_id for dag_run in dag_runs]),
        )
        .group_by(TaskInstance.task_id, TaskInstance.run_id, TaskInstance.state)
        .order_by(TaskInstance.task_id, TaskInstance.run_id)
    )

    grouped_tis = {task_id: list(tis) for task_id, tis in itertools.groupby(query, key=lambda ti: ti.task_id)}

    def task_group_to_grid(item, dag_runs, grouped_tis):
        if isinstance(item, AbstractOperator):

            def _get_summary(task_instance):
                try_count = (
                    task_instance._try_number
                    if task_instance._try_number != 0 or task_instance.state in State.running
                    else task_instance._try_number + 1
                )

                return {
                    'task_id': task_instance.task_id,
                    'run_id': task_instance.run_id,
                    'state': task_instance.state,
                    'start_date': task_instance.start_date,
                    'end_date': task_instance.end_date,
                    'try_number': try_count,
                }

            def _mapped_summary(ti_summaries):
                run_id = None
                record = None

                def set_overall_state(record):
                    for state in wwwutils.priority:
                        if state in record['mapped_states']:
                            record['state'] = state
                            break
                    if None in record['mapped_states']:
                        # When turnong the dict into JSON we can't have None as a key, so use the string that
                        # the UI does
                        record['mapped_states']['no_status'] = record['mapped_states'].pop(None)

                for ti_summary in ti_summaries:
                    if ti_summary.state is None:
                        ti_summary.state == 'no_status'
                    if run_id != ti_summary.run_id:
                        run_id = ti_summary.run_id
                        if record:
                            set_overall_state(record)
                            yield record
                        record = {
                            'task_id': ti_summary.task_id,
                            'run_id': run_id,
                            'start_date': ti_summary.start_date,
                            'end_date': ti_summary.end_date,
                            'mapped_states': {ti_summary.state: ti_summary.state_count},
                            'state': None,  # We change this before yielding
                        }
                        continue
                    record['start_date'] = min(
                        filter(None, [record['start_date'], ti_summary.start_date]), default=None
                    )
                    record['end_date'] = max(
                        filter(None, [record['end_date'], ti_summary.end_date]), default=None
                    )
                    record['mapped_states'][ti_summary.state] = ti_summary.state_count
                if record:
                    set_overall_state(record)
                    yield record

            if item.is_mapped:
                instances = list(_mapped_summary(grouped_tis.get(item.task_id, [])))
            else:
                instances = list(map(_get_summary, grouped_tis.get(item.task_id, [])))

            return {
                'id': item.task_id,
                'instances': instances,
                'label': item.label,
                'extra_links': item.extra_links,
                'is_mapped': item.is_mapped,
                'has_outlet_datasets': any(isinstance(i, Dataset) for i in getattr(item, "_outlets", [])),
                'operator': item.task_type,
            }

        # Task Group
        task_group = item

        children = [
            task_group_to_grid(child, dag_runs, grouped_tis) for child in task_group.topological_sort()
        ]

        def get_summary(dag_run, children):
            child_instances = [child['instances'] for child in children if 'instances' in child]
            child_instances = [
                item for sublist in child_instances for item in sublist if item['run_id'] == dag_run.run_id
            ]

            children_start_dates = (item['start_date'] for item in child_instances if item)
            children_end_dates = (item['end_date'] for item in child_instances if item)
            children_states = {item['state'] for item in child_instances if item}

            group_state = None
            for state in wwwutils.priority:
                if state in children_states:
                    group_state = state
                    break
            group_start_date = min(filter(None, children_start_dates), default=None)
            group_end_date = max(filter(None, children_end_dates), default=None)

            return {
                'task_id': task_group.group_id,
                'run_id': dag_run.run_id,
                'state': group_state,
                'start_date': group_start_date,
                'end_date': group_end_date,
            }

        # We don't need to calculate summaries for the root
        if task_group.group_id is None:
            return {
                'id': task_group.group_id,
                'label': task_group.label,
                'children': children,
                'instances': [],
            }

        group_summaries = [get_summary(dr, children) for dr in dag_runs]

        return {
            'id': task_group.group_id,
            'label': task_group.label,
            'children': children,
            'tooltip': task_group.tooltip,
            'instances': group_summaries,
        }

    return task_group_to_grid(dag.task_group, dag_runs, grouped_tis)


def task_group_to_dict(task_item_or_group):
    """
    Create a nested dict representation of this TaskGroup and its children used to construct
    the Graph.
    """
    if isinstance(task_item_or_group, AbstractOperator):
        return {
            'id': task_item_or_group.task_id,
            'value': {
                'label': task_item_or_group.label,
                'labelStyle': f"fill:{task_item_or_group.ui_fgcolor};",
                'style': f"fill:{task_item_or_group.ui_color};",
                'rx': 5,
                'ry': 5,
            },
        }
    task_group = task_item_or_group
    children = [
        task_group_to_dict(child) for child in sorted(task_group.children.values(), key=lambda t: t.label)
    ]

    if task_group.upstream_group_ids or task_group.upstream_task_ids:
        children.append(
            {
                'id': task_group.upstream_join_id,
                'value': {
                    'label': '',
                    'labelStyle': f"fill:{task_group.ui_fgcolor};",
                    'style': f"fill:{task_group.ui_color};",
                    'shape': 'circle',
                },
            }
        )

    if task_group.downstream_group_ids or task_group.downstream_task_ids:
        # This is the join node used to reduce the number of edges between two TaskGroup.
        children.append(
            {
                'id': task_group.downstream_join_id,
                'value': {
                    'label': '',
                    'labelStyle': f"fill:{task_group.ui_fgcolor};",
                    'style': f"fill:{task_group.ui_color};",
                    'shape': 'circle',
                },
            }
        )

    return {
        "id": task_group.group_id,
        'value': {
            'label': task_group.label,
            'labelStyle': f"fill:{task_group.ui_fgcolor};",
            'style': f"fill:{task_group.ui_color}",
            'rx': 5,
            'ry': 5,
            'clusterLabelPos': 'top',
            'tooltip': task_group.tooltip,
        },
        'children': children,
    }


def get_key_paths(input_dict):
    """Return a list of dot-separated dictionary paths"""
    for key, value in input_dict.items():
        if isinstance(value, dict):
            for sub_key in get_key_paths(value):
                yield '.'.join((key, sub_key))
        else:
            yield key


def get_value_from_path(key_path, content):
    """Return the value from a dictionary based on dot-separated path of keys"""
    elem = content
    for x in key_path.strip(".").split("."):
        try:
            x = int(x)
            elem = elem[x]
        except ValueError:
            elem = elem.get(x)

    return elem


def dag_edges(dag):
    """
    Create the list of edges needed to construct the Graph view.

    A special case is made if a TaskGroup is immediately upstream/downstream of another
    TaskGroup or task. Two dummy nodes named upstream_join_id and downstream_join_id are
    created for the TaskGroup. Instead of drawing an edge onto every task in the TaskGroup,
    all edges are directed onto the dummy nodes. This is to cut down the number of edges on
    the graph.

    For example: A DAG with TaskGroups group1 and group2:
        group1: task1, task2, task3
        group2: task4, task5, task6

    group2 is downstream of group1:
        group1 >> group2

    Edges to add (This avoids having to create edges between every task in group1 and group2):
        task1 >> downstream_join_id
        task2 >> downstream_join_id
        task3 >> downstream_join_id
        downstream_join_id >> upstream_join_id
        upstream_join_id >> task4
        upstream_join_id >> task5
        upstream_join_id >> task6
    """
    # Edges to add between TaskGroup
    edges_to_add = set()
    # Edges to remove between individual tasks that are replaced by edges_to_add.
    edges_to_skip = set()

    task_group_map = dag.task_group.get_task_group_dict()

    def collect_edges(task_group):
        """Update edges_to_add and edges_to_skip according to TaskGroups."""
        if isinstance(task_group, AbstractOperator):
            return

        for target_id in task_group.downstream_group_ids:
            # For every TaskGroup immediately downstream, add edges between downstream_join_id
            # and upstream_join_id. Skip edges between individual tasks of the TaskGroups.
            target_group = task_group_map[target_id]
            edges_to_add.add((task_group.downstream_join_id, target_group.upstream_join_id))

            for child in task_group.get_leaves():
                edges_to_add.add((child.task_id, task_group.downstream_join_id))
                for target in target_group.get_roots():
                    edges_to_skip.add((child.task_id, target.task_id))
                edges_to_skip.add((child.task_id, target_group.upstream_join_id))

            for child in target_group.get_roots():
                edges_to_add.add((target_group.upstream_join_id, child.task_id))
                edges_to_skip.add((task_group.downstream_join_id, child.task_id))

        # For every individual task immediately downstream, add edges between downstream_join_id and
        # the downstream task. Skip edges between individual tasks of the TaskGroup and the
        # downstream task.
        for target_id in task_group.downstream_task_ids:
            edges_to_add.add((task_group.downstream_join_id, target_id))

            for child in task_group.get_leaves():
                edges_to_add.add((child.task_id, task_group.downstream_join_id))
                edges_to_skip.add((child.task_id, target_id))

        # For every individual task immediately upstream, add edges between the upstream task
        # and upstream_join_id. Skip edges between the upstream task and individual tasks
        # of the TaskGroup.
        for source_id in task_group.upstream_task_ids:
            edges_to_add.add((source_id, task_group.upstream_join_id))
            for child in task_group.get_roots():
                edges_to_add.add((task_group.upstream_join_id, child.task_id))
                edges_to_skip.add((source_id, child.task_id))

        for child in task_group.children.values():
            collect_edges(child)

    collect_edges(dag.task_group)

    # Collect all the edges between individual tasks
    edges = set()

    def get_downstream(task):
        for child in task.downstream_list:
            edge = (task.task_id, child.task_id)
            if edge not in edges:
                edges.add(edge)
                get_downstream(child)

    for root in dag.roots:
        get_downstream(root)

    result = []
    # Build result dicts with the two ends of the edge, plus any extra metadata
    # if we have it.
    for source_id, target_id in sorted(edges.union(edges_to_add) - edges_to_skip):
        record = {"source_id": source_id, "target_id": target_id}
        label = dag.get_edge_info(source_id, target_id).get("label")
        if label:
            record["label"] = label
        result.append(record)
    return result


def get_task_stats_from_query(qry):
    """
    Return a dict of the task quantity, grouped by dag id and task status.

    :param qry: The data in the format (<dag id>, <task state>, <is dag running>, <task count>),
        ordered by <dag id> and <is dag running>
    """
    data = {}
    last_dag_id = None
    has_running_dags = False
    for dag_id, state, is_dag_running, count in qry:
        if last_dag_id != dag_id:
            last_dag_id = dag_id
            has_running_dags = False
        elif not is_dag_running and has_running_dags:
            continue

        if is_dag_running:
            has_running_dags = True
        if dag_id not in data:
            data[dag_id] = {}
        data[dag_id][state] = count
    return data


def redirect_or_json(origin, msg, status="", status_code=200):
    """
    Some endpoints are called by javascript,
    returning json will allow us to more elegantly handle side-effects in-page
    """
    if request.headers.get('Accept') == 'application/json':
        if status == 'error' and status_code == 200:
            status_code = 500
        return Response(response=msg, status=status_code, mimetype="application/json")
    else:
        if status:
            flash(msg, status)
        else:
            flash(msg)
        return redirect(origin)


######################################################################################
#                                    Error handlers
######################################################################################


def not_found(error):
    """Show Not Found on screen for any error in the Webserver"""
    return (
        render_template(
            'airflow/not_found.html',
            hostname=get_hostname()
            if conf.getboolean('webserver', 'EXPOSE_HOSTNAME', fallback=True)
            else 'redact',
        ),
        404,
    )


def show_traceback(error):
    """Show Traceback for a given error"""
    return (
        render_template(
            'airflow/traceback.html',
            python_version=sys.version.split(" ")[0],
            airflow_version=version,
            hostname=get_hostname()
            if conf.getboolean('webserver', 'EXPOSE_HOSTNAME', fallback=True)
            else 'redact',
            info=traceback.format_exc()
            if conf.getboolean('webserver', 'EXPOSE_STACKTRACE', fallback=True)
            else 'Error! Please contact server admin.',
        ),
        500,
    )


######################################################################################
#                                    BaseViews
######################################################################################


class AirflowBaseView(BaseView):
    """Base View to set Airflow related properties"""

    from airflow import macros

    route_base = ''

    extra_args = {
        # Make our macros available to our UI templates too.
        'macros': macros,
        'get_docs_url': get_docs_url,
    }

    if not conf.getboolean('core', 'unit_test_mode'):
        extra_args['sqlite_warning'] = settings.engine.dialect.name == 'sqlite'
        extra_args['sequential_executor_warning'] = conf.get('core', 'executor') == 'SequentialExecutor'

    line_chart_attr = {
        'legend.maxKeyLength': 200,
    }

    def render_template(self, *args, **kwargs):
        # Add triggerer_job only if we need it
        if TriggererJob.is_needed():
            kwargs["triggerer_job"] = lazy_object_proxy.Proxy(TriggererJob.most_recent_job)
        return super().render_template(
            *args,
            # Cache this at most once per request, not for the lifetime of the view instance
            scheduler_job=lazy_object_proxy.Proxy(SchedulerJob.most_recent_job),
            **kwargs,
        )


class Airflow(AirflowBaseView):
    """Main Airflow application."""

    @expose('/health')
    def health(self):
        """
        An endpoint helping check the health status of the Airflow instance,
        including metadatabase and scheduler.
        """
        payload = {'metadatabase': {'status': 'unhealthy'}}

        latest_scheduler_heartbeat = None
        scheduler_status = 'unhealthy'
        payload['metadatabase'] = {'status': 'healthy'}
        try:
            scheduler_job = SchedulerJob.most_recent_job()

            if scheduler_job:
                latest_scheduler_heartbeat = scheduler_job.latest_heartbeat.isoformat()
                if scheduler_job.is_alive():
                    scheduler_status = 'healthy'
        except Exception:
            payload['metadatabase']['status'] = 'unhealthy'

        payload['scheduler'] = {
            'status': scheduler_status,
            'latest_scheduler_heartbeat': latest_scheduler_heartbeat,
        }

        return wwwutils.json_response(payload)

    @expose('/home')
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_WEBSITE),
        ]
    )
    def index(self):
        """Home view."""
        hide_paused_dags_by_default = conf.getboolean('webserver', 'hide_paused_dags_by_default')
        default_dag_run = conf.getint('webserver', 'default_dag_run_display_number')

        num_runs = request.args.get('num_runs', default=default_dag_run, type=int)
        current_page = request.args.get('page', default=0, type=int)
        arg_search_query = request.args.get('search')
        arg_tags_filter = request.args.getlist('tags')
        arg_status_filter = request.args.get('status')
        arg_sorting_key = request.args.get('sorting_key', 'dag_id')
        arg_sorting_direction = request.args.get('sorting_direction', default='asc')

        if request.args.get('reset_tags') is not None:
            flask_session[FILTER_TAGS_COOKIE] = None
            # Remove the reset_tags=reset from the URL
            return redirect(url_for('Airflow.index'))

        cookie_val = flask_session.get(FILTER_TAGS_COOKIE)
        if arg_tags_filter:
            flask_session[FILTER_TAGS_COOKIE] = ','.join(arg_tags_filter)
        elif cookie_val:
            # If tags exist in cookie, but not URL, add them to the URL
            return redirect(url_for('Airflow.index', tags=cookie_val.split(',')))

        if arg_status_filter is None:
            cookie_val = flask_session.get(FILTER_STATUS_COOKIE)
            if cookie_val:
                arg_status_filter = cookie_val
            else:
                arg_status_filter = 'active' if hide_paused_dags_by_default else 'all'
                flask_session[FILTER_STATUS_COOKIE] = arg_status_filter
        else:
            status = arg_status_filter.strip().lower()
            flask_session[FILTER_STATUS_COOKIE] = status
            arg_status_filter = status

        dags_per_page = PAGE_SIZE

        start = current_page * dags_per_page
        end = start + dags_per_page

        # Get all the dag id the user could access
        filter_dag_ids = get_airflow_app().appbuilder.sm.get_accessible_dag_ids(g.user)

        with create_session() as session:
            # read orm_dags from the db
            dags_query = session.query(DagModel).filter(~DagModel.is_subdag, DagModel.is_active)

            if arg_search_query:
                dags_query = dags_query.filter(
                    DagModel.dag_id.ilike('%' + arg_search_query + '%')
                    | DagModel.owners.ilike('%' + arg_search_query + '%')
                )

            if arg_tags_filter:
                dags_query = dags_query.filter(DagModel.tags.any(DagTag.name.in_(arg_tags_filter)))

            dags_query = dags_query.filter(DagModel.dag_id.in_(filter_dag_ids))

            all_dags = dags_query
            active_dags = dags_query.filter(~DagModel.is_paused)
            paused_dags = dags_query.filter(DagModel.is_paused)

            is_paused_count = dict(
                all_dags.with_entities(DagModel.is_paused, func.count(DagModel.dag_id))
                .group_by(DagModel.is_paused)
                .all()
            )
            status_count_active = is_paused_count.get(False, 0)
            status_count_paused = is_paused_count.get(True, 0)
            all_dags_count = status_count_active + status_count_paused
            if arg_status_filter == 'active':
                current_dags = active_dags
                num_of_all_dags = status_count_active
            elif arg_status_filter == 'paused':
                current_dags = paused_dags
                num_of_all_dags = status_count_paused
            else:
                current_dags = all_dags
                num_of_all_dags = all_dags_count

            sort_column = DagModel.__table__.c.get(arg_sorting_key)
            if sort_column is not None:
                if arg_sorting_direction == 'desc':
                    sort_column = sort_column.desc()
                current_dags = current_dags.order_by(sort_column)

            dags = current_dags.options(joinedload(DagModel.tags)).offset(start).limit(dags_per_page).all()
            user_permissions = g.user.perms
            all_dags_editable = (permissions.ACTION_CAN_EDIT, permissions.RESOURCE_DAG) in user_permissions
            can_create_dag_run = (
                permissions.ACTION_CAN_CREATE,
                permissions.RESOURCE_DAG_RUN,
            ) in user_permissions

            all_dags_deletable = (
                permissions.ACTION_CAN_DELETE,
                permissions.RESOURCE_DAG,
            ) in user_permissions

            dataset_triggered_dag_ids = {dag.dag_id for dag in dags if dag.schedule_interval == "Dataset"}
            if dataset_triggered_dag_ids:
                dataset_triggered_next_run_info = get_dataset_triggered_next_run_info(
                    dataset_triggered_dag_ids, session=session
                )
            else:
                dataset_triggered_next_run_info = {}

            for dag in dags:
                dag_resource_name = permissions.RESOURCE_DAG_PREFIX + dag.dag_id
                if all_dags_editable:
                    dag.can_edit = True
                else:
                    dag.can_edit = (permissions.ACTION_CAN_EDIT, dag_resource_name) in user_permissions
                dag.can_trigger = dag.can_edit and can_create_dag_run
                if all_dags_deletable:
                    dag.can_delete = True
                else:
                    dag.can_delete = (permissions.ACTION_CAN_DELETE, dag_resource_name) in user_permissions

            dagtags = session.query(DagTag.name).distinct(DagTag.name).all()
            tags = [
                {"name": name, "selected": bool(arg_tags_filter and name in arg_tags_filter)}
                for name, in dagtags
            ]

            owner_links_dict = DagOwnerAttributes.get_all(session)

            import_errors = session.query(errors.ImportError).order_by(errors.ImportError.id)

            if (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG) not in user_permissions:
                # if the user doesn't have access to all DAGs, only display errors from visible DAGs
                import_errors = import_errors.join(
                    DagModel, DagModel.fileloc == errors.ImportError.filename
                ).filter(DagModel.dag_id.in_(filter_dag_ids))

            for import_error in import_errors:
                flash(
                    "Broken DAG: [{ie.filename}] {ie.stacktrace}".format(ie=import_error),
                    "dag_import_error",
                )

        from airflow.plugins_manager import import_errors as plugin_import_errors

        for filename, stacktrace in plugin_import_errors.items():
            flash(
                f"Broken plugin: [{filename}] {stacktrace}",
                "error",
            )

        num_of_pages = int(math.ceil(num_of_all_dags / float(dags_per_page)))

        state_color_mapping = State.state_color.copy()
        state_color_mapping["null"] = state_color_mapping.pop(None)

        page_title = conf.get(section="webserver", key="instance_name", fallback="DAGs")
        page_title_has_markup = conf.getboolean(
            section="webserver", key="instance_name_has_markup", fallback=False
        )

        dashboard_alerts = [
            fm for fm in settings.DASHBOARD_UIALERTS if fm.should_show(get_airflow_app().appbuilder.sm)
        ]

        def _iter_parsed_moved_data_table_names():
            for table_name in inspect(session.get_bind()).get_table_names():
                segments = table_name.split("__", 3)
                if len(segments) < 3:
                    continue
                if segments[0] != settings.AIRFLOW_MOVED_TABLE_PREFIX:
                    continue
                # Second segment is a version marker that we don't need to show.
                yield segments[-1], table_name

        if (
            permissions.ACTION_CAN_ACCESS_MENU,
            permissions.RESOURCE_ADMIN_MENU,
        ) in user_permissions and conf.getboolean("webserver", "warn_deployment_exposure"):
            robots_file_access_count = (
                session.query(Log)
                .filter(Log.event == "robots")
                .filter(Log.dttm > (utcnow() - timedelta(days=7)))
                .count()
            )
            if robots_file_access_count > 0:
                flash(
                    Markup(
                        'Recent requests have been made to /robots.txt. '
                        'This indicates that this deployment may be accessible to the public internet. '
                        'This warning can be disabled by setting webserver.warn_deployment_exposure=False in '
                        'airflow.cfg. Read more about web deployment security <a href='
                        f'"{get_docs_url("security/webserver.html")}">'
                        'here</a>'
                    ),
                    "warning",
                )

        return self.render_template(
            'airflow/dags.html',
            dags=dags,
            dashboard_alerts=dashboard_alerts,
            migration_moved_data_alerts=sorted(set(_iter_parsed_moved_data_table_names())),
            current_page=current_page,
            search_query=arg_search_query if arg_search_query else '',
            page_title=Markup(page_title) if page_title_has_markup else page_title,
            page_size=dags_per_page,
            num_of_pages=num_of_pages,
            num_dag_from=min(start + 1, num_of_all_dags),
            num_dag_to=min(end, num_of_all_dags),
            num_of_all_dags=num_of_all_dags,
            paging=wwwutils.generate_pages(
                current_page,
                num_of_pages,
                search=escape(arg_search_query) if arg_search_query else None,
                status=arg_status_filter if arg_status_filter else None,
                tags=arg_tags_filter if arg_tags_filter else None,
            ),
            num_runs=num_runs,
            tags=tags,
            owner_links=owner_links_dict,
            state_color=state_color_mapping,
            status_filter=arg_status_filter,
            status_count_all=all_dags_count,
            status_count_active=status_count_active,
            status_count_paused=status_count_paused,
            tags_filter=arg_tags_filter,
            sorting_key=arg_sorting_key,
            sorting_direction=arg_sorting_direction,
            auto_refresh_interval=conf.getint('webserver', 'auto_refresh_interval'),
            dataset_triggered_next_run_info=dataset_triggered_next_run_info,
        )

    @expose('/datasets')
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DATASET),
        ]
    )
    def datasets(self):
        """Datasets view."""
        return self.render_template(
            'airflow/datasets.html',
        )

    @expose('/dag_stats', methods=['POST'])
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG_RUN),
        ]
    )
    @provide_session
    def dag_stats(self, session=None):
        """Dag statistics."""
        dr = models.DagRun

        allowed_dag_ids = get_airflow_app().appbuilder.sm.get_accessible_dag_ids(g.user)

        dag_state_stats = session.query(dr.dag_id, dr.state, sqla.func.count(dr.state)).group_by(
            dr.dag_id, dr.state
        )

        # Filter by post parameters
        selected_dag_ids = {unquote(dag_id) for dag_id in request.form.getlist('dag_ids') if dag_id}

        if selected_dag_ids:
            filter_dag_ids = selected_dag_ids.intersection(allowed_dag_ids)
        else:
            filter_dag_ids = allowed_dag_ids

        if not filter_dag_ids:
            return wwwutils.json_response({})

        payload = {}
        dag_state_stats = dag_state_stats.filter(dr.dag_id.in_(filter_dag_ids))
        data = {}

        for dag_id, state, count in dag_state_stats:
            if dag_id not in data:
                data[dag_id] = {}
            data[dag_id][state] = count

        for dag_id in filter_dag_ids:
            payload[dag_id] = []
            for state in State.dag_states:
                count = data.get(dag_id, {}).get(state, 0)
                payload[dag_id].append({'state': state, 'count': count})

        return wwwutils.json_response(payload)

    @expose('/task_stats', methods=['POST'])
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG_RUN),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_TASK_INSTANCE),
        ]
    )
    @provide_session
    def task_stats(self, session=None):
        """Task Statistics"""
        allowed_dag_ids = get_airflow_app().appbuilder.sm.get_accessible_dag_ids(g.user)

        if not allowed_dag_ids:
            return wwwutils.json_response({})

        # Filter by post parameters
        selected_dag_ids = {unquote(dag_id) for dag_id in request.form.getlist('dag_ids') if dag_id}

        if selected_dag_ids:
            filter_dag_ids = selected_dag_ids.intersection(allowed_dag_ids)
        else:
            filter_dag_ids = allowed_dag_ids

        running_dag_run_query_result = (
            session.query(DagRun.dag_id, DagRun.run_id)
            .join(DagModel, DagModel.dag_id == DagRun.dag_id)
            .filter(DagRun.state == State.RUNNING, DagModel.is_active)
        )

        running_dag_run_query_result = running_dag_run_query_result.filter(DagRun.dag_id.in_(filter_dag_ids))

        running_dag_run_query_result = running_dag_run_query_result.subquery('running_dag_run')

        # Select all task_instances from active dag_runs.
        running_task_instance_query_result = session.query(
            TaskInstance.dag_id.label('dag_id'),
            TaskInstance.state.label('state'),
            sqla.literal(True).label('is_dag_running'),
        ).join(
            running_dag_run_query_result,
            and_(
                running_dag_run_query_result.c.dag_id == TaskInstance.dag_id,
                running_dag_run_query_result.c.run_id == TaskInstance.run_id,
            ),
        )

        if conf.getboolean('webserver', 'SHOW_RECENT_STATS_FOR_COMPLETED_RUNS', fallback=True):

            last_dag_run = (
                session.query(DagRun.dag_id, sqla.func.max(DagRun.execution_date).label('execution_date'))
                .join(DagModel, DagModel.dag_id == DagRun.dag_id)
                .filter(DagRun.state != State.RUNNING, DagModel.is_active)
                .group_by(DagRun.dag_id)
            )

            last_dag_run = last_dag_run.filter(DagRun.dag_id.in_(filter_dag_ids))
            last_dag_run = last_dag_run.subquery('last_dag_run')

            # Select all task_instances from active dag_runs.
            # If no dag_run is active, return task instances from most recent dag_run.
            last_task_instance_query_result = (
                session.query(
                    TaskInstance.dag_id.label('dag_id'),
                    TaskInstance.state.label('state'),
                    sqla.literal(False).label('is_dag_running'),
                )
                .join(TaskInstance.dag_run)
                .join(
                    last_dag_run,
                    and_(
                        last_dag_run.c.dag_id == TaskInstance.dag_id,
                        last_dag_run.c.execution_date == DagRun.execution_date,
                    ),
                )
            )

            final_task_instance_query_result = union_all(
                last_task_instance_query_result, running_task_instance_query_result
            ).alias('final_ti')
        else:
            final_task_instance_query_result = running_task_instance_query_result.subquery('final_ti')

        qry = (
            session.query(
                final_task_instance_query_result.c.dag_id,
                final_task_instance_query_result.c.state,
                final_task_instance_query_result.c.is_dag_running,
                sqla.func.count(),
            )
            .group_by(
                final_task_instance_query_result.c.dag_id,
                final_task_instance_query_result.c.state,
                final_task_instance_query_result.c.is_dag_running,
            )
            .order_by(
                final_task_instance_query_result.c.dag_id,
                final_task_instance_query_result.c.is_dag_running.desc(),
            )
        )

        data = get_task_stats_from_query(qry)
        payload = {}
        for dag_id in filter_dag_ids:
            payload[dag_id] = []
            for state in State.task_states:
                count = data.get(dag_id, {}).get(state, 0)
                payload[dag_id].append({'state': state, 'count': count})
        return wwwutils.json_response(payload)

    @expose('/last_dagruns', methods=['POST'])
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG_RUN),
        ]
    )
    @provide_session
    def last_dagruns(self, session=None):
        """Last DAG runs"""
        allowed_dag_ids = get_airflow_app().appbuilder.sm.get_accessible_dag_ids(g.user)

        # Filter by post parameters
        selected_dag_ids = {unquote(dag_id) for dag_id in request.form.getlist('dag_ids') if dag_id}

        if selected_dag_ids:
            filter_dag_ids = selected_dag_ids.intersection(allowed_dag_ids)
        else:
            filter_dag_ids = allowed_dag_ids

        if not filter_dag_ids:
            return wwwutils.json_response({})

        last_runs_subquery = (
            session.query(
                DagRun.dag_id,
                sqla.func.max(DagRun.execution_date).label("max_execution_date"),
            )
            .group_by(DagRun.dag_id)
            .filter(DagRun.dag_id.in_(filter_dag_ids))  # Only include accessible/selected DAGs.
            .subquery("last_runs")
        )

        query = session.query(
            DagRun.dag_id,
            DagRun.start_date,
            DagRun.end_date,
            DagRun.state,
            DagRun.execution_date,
            DagRun.data_interval_start,
            DagRun.data_interval_end,
        ).join(
            last_runs_subquery,
            and_(
                last_runs_subquery.c.dag_id == DagRun.dag_id,
                last_runs_subquery.c.max_execution_date == DagRun.execution_date,
            ),
        )

        resp = {
            r.dag_id.replace('.', '__dot__'): {
                "dag_id": r.dag_id,
                "state": r.state,
                "execution_date": wwwutils.datetime_to_string(r.execution_date),
                "start_date": wwwutils.datetime_to_string(r.start_date),
                "end_date": wwwutils.datetime_to_string(r.end_date),
                "data_interval_start": wwwutils.datetime_to_string(r.data_interval_start),
                "data_interval_end": wwwutils.datetime_to_string(r.data_interval_end),
            }
            for r in query
        }
        return wwwutils.json_response(resp)

    @expose('/code')
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG_CODE),
        ]
    )
    def legacy_code(self):
        """Redirect from url param."""
        return redirect(url_for('Airflow.code', **request.args))

    @expose('/dags/<string:dag_id>/code')
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG_CODE),
        ]
    )
    @provide_session
    def code(self, dag_id, session=None):
        """Dag Code."""
        dag = get_airflow_app().dag_bag.get_dag(dag_id, session=session)
        dag_model = DagModel.get_dagmodel(dag_id, session=session)
        if not dag:
            flash(f'DAG "{dag_id}" seems to be missing.', "error")
            return redirect(url_for('Airflow.index'))

        wwwutils.check_import_errors(dag_model.fileloc, session)
        wwwutils.check_dag_warnings(dag_model.dag_id, session)

        try:
            code = DagCode.get_code_by_fileloc(dag_model.fileloc)
            html_code = Markup(highlight(code, lexers.PythonLexer(), HtmlFormatter(linenos=True)))
        except Exception as e:
            error = f"Exception encountered during dag code retrieval/code highlighting:\n\n{e}\n"
            html_code = Markup('<p>Failed to load DAG file Code.</p><p>Details: {}</p>').format(escape(error))

        return self.render_template(
            'airflow/dag_code.html',
            html_code=html_code,
            dag=dag,
            dag_model=dag_model,
            title=dag_id,
            root=request.args.get('root'),
            wrapped=conf.getboolean('webserver', 'default_wrap'),
        )

    @expose('/dag_details')
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG_RUN),
        ]
    )
    def legacy_dag_details(self):
        """Redirect from url param."""
        return redirect(url_for('Airflow.dag_details', **request.args))

    @expose('/dags/<string:dag_id>/details')
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG_RUN),
        ]
    )
    @provide_session
    def dag_details(self, dag_id, session=None):
        """Get Dag details."""
        dag = get_airflow_app().dag_bag.get_dag(dag_id, session=session)
        dag_model = DagModel.get_dagmodel(dag_id, session=session)
        if not dag:
            flash(f'DAG "{dag_id}" seems to be missing.', "error")
            return redirect(url_for('Airflow.index'))

        wwwutils.check_import_errors(dag.fileloc, session)
        wwwutils.check_dag_warnings(dag.dag_id, session)

        title = "DAG Details"
        root = request.args.get('root', '')

        states = (
            session.query(TaskInstance.state, sqla.func.count(TaskInstance.dag_id))
            .filter(TaskInstance.dag_id == dag_id)
            .group_by(TaskInstance.state)
            .all()
        )

        active_runs = models.DagRun.find(dag_id=dag_id, state=State.RUNNING, external_trigger=False)

        tags = session.query(models.DagTag).filter(models.DagTag.dag_id == dag_id).all()

        owner_links = (
            session.query(models.DagOwnerAttributes).filter(models.DagOwnerAttributes.dag_id == dag_id).all()
        )

        attrs_to_avoid = [
            "NUM_DAGS_PER_DAGRUN_QUERY",
            "serialized_dag",
            "tags",
            "default_view",
            "relative_fileloc",
            "dag_id",
            "description",
            "max_active_runs",
            "max_active_tasks",
            "schedule_interval",
            "owners",
            "dag_owner_links",
            "is_paused",
        ]
        attrs_to_avoid.extend(wwwutils.get_attr_renderer().keys())
        dag_model_attrs: List[Tuple[str, Any]] = [
            (attr_name, attr)
            for attr_name, attr in (
                (attr_name, getattr(dag_model, attr_name))
                for attr_name in dir(dag_model)
                if not attr_name.startswith("_") and attr_name not in attrs_to_avoid
            )
            if not callable(attr)
        ]

        return self.render_template(
            'airflow/dag_details.html',
            dag=dag,
            dag_model=dag_model,
            title=title,
            root=root,
            states=states,
            State=State,
            active_runs=active_runs,
            tags=tags,
            owner_links=owner_links,
            dag_model_attrs=dag_model_attrs,
        )

    @expose('/rendered-templates')
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_TASK_INSTANCE),
        ]
    )
    @action_logging
    @provide_session
    def rendered_templates(self, session):
        """Get rendered Dag."""
        dag_id = request.args.get('dag_id')
        task_id = request.args.get('task_id')
        map_index = request.args.get('map_index', -1, type=int)
        execution_date = request.args.get('execution_date')
        dttm = _safe_parse_datetime(execution_date)
        form = DateTimeForm(data={'execution_date': dttm})
        root = request.args.get('root', '')

        logging.info("Retrieving rendered templates.")
        dag: DAG = get_airflow_app().dag_bag.get_dag(dag_id)
        dag_run = dag.get_dagrun(execution_date=dttm, session=session)
        raw_task = dag.get_task(task_id).prepare_for_execution()

        ti: TaskInstance
        if dag_run is None:
            # No DAG run matching given logical date. This usually means this
            # DAG has never been run. Task instance rendering does not really
            # make sense in this situation, but "works" prior to AIP-39. This
            # "fakes" a temporary DagRun-TaskInstance association (not saved to
            # database) for presentation only.
            ti = TaskInstance(raw_task, map_index=map_index)
            ti.dag_run = DagRun(dag_id=dag_id, execution_date=dttm)
        else:
            ti = dag_run.get_task_instance(task_id=task_id, map_index=map_index, session=session)
            ti.refresh_from_task(raw_task)

        try:
            ti.get_rendered_template_fields(session=session)
        except AirflowException as e:
            msg = "Error rendering template: " + escape(e)
            if e.__cause__:
                msg += Markup("<br><br>OriginalError: ") + escape(e.__cause__)
            flash(msg, "error")
        except Exception as e:
            flash("Error rendering template: " + str(e), "error")

        # Ensure we are rendering the unmapped operator. Unmapping should be
        # done automatically if template fields are rendered successfully; this
        # only matters if get_rendered_template_fields() raised an exception.
        # The following rendering won't show useful values in this case anyway,
        # but we'll display some quasi-meaingful field names.
        task = ti.task.unmap(None)

        title = "Rendered Template"
        html_dict = {}
        renderers = wwwutils.get_attr_renderer()

        for template_field in task.template_fields:
            content = getattr(task, template_field)
            renderer = task.template_fields_renderers.get(template_field, template_field)
            if renderer in renderers:
                if isinstance(content, (dict, list)):
                    json_content = json.dumps(content, sort_keys=True, indent=4)
                    html_dict[template_field] = renderers[renderer](json_content)
                else:
                    html_dict[template_field] = renderers[renderer](content)
            else:
                html_dict[template_field] = Markup("<pre><code>{}</pre></code>").format(pformat(content))

            if isinstance(content, dict):
                if template_field == 'op_kwargs':
                    for key, value in content.items():
                        renderer = task.template_fields_renderers.get(key, key)
                        if renderer in renderers:
                            html_dict['.'.join([template_field, key])] = renderers[renderer](value)
                        else:
                            html_dict['.'.join([template_field, key])] = Markup(
                                "<pre><code>{}</pre></code>"
                            ).format(pformat(value))
                else:
                    for dict_keys in get_key_paths(content):
                        template_path = '.'.join((template_field, dict_keys))
                        renderer = task.template_fields_renderers.get(template_path, template_path)
                        if renderer in renderers:
                            content_value = get_value_from_path(dict_keys, content)
                            html_dict[template_path] = renderers[renderer](content_value)

        return self.render_template(
            'airflow/ti_code.html',
            html_dict=html_dict,
            dag=dag,
            task_id=task_id,
            execution_date=execution_date,
            map_index=map_index,
            form=form,
            root=root,
            title=title,
        )

    @expose('/rendered-k8s')
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_TASK_INSTANCE),
        ]
    )
    @action_logging
    @provide_session
    def rendered_k8s(self, session: Session = NEW_SESSION):
        """Get rendered k8s yaml."""
        if not settings.IS_K8S_OR_K8SCELERY_EXECUTOR:
            abort(404)
        dag_id = request.args.get('dag_id')
        task_id = request.args.get('task_id')
        if task_id is None:
            logging.warning("Task id not passed in the request")
            abort(400)
        execution_date = request.args.get('execution_date')
        dttm = _safe_parse_datetime(execution_date)
        form = DateTimeForm(data={'execution_date': dttm})
        root = request.args.get('root', '')
        map_index = request.args.get('map_index', -1, type=int)
        logging.info("Retrieving rendered templates.")

        dag: DAG = get_airflow_app().dag_bag.get_dag(dag_id)
        task = dag.get_task(task_id)
        dag_run = dag.get_dagrun(execution_date=dttm, session=session)
        ti = dag_run.get_task_instance(task_id=task.task_id, map_index=map_index, session=session)

        pod_spec = None
        try:
            pod_spec = ti.get_rendered_k8s_spec(session=session)
        except AirflowException as e:
            msg = "Error rendering Kubernetes POD Spec: " + escape(e)
            if e.__cause__:
                msg += Markup("<br><br>OriginalError: ") + escape(e.__cause__)
            flash(msg, "error")
        except Exception as e:
            flash("Error rendering Kubernetes Pod Spec: " + str(e), "error")
        title = "Rendered K8s Pod Spec"
        html_dict = {}
        renderers = wwwutils.get_attr_renderer()
        if pod_spec:
            content = yaml.dump(pod_spec)
            content = renderers["yaml"](content)
        else:
            content = Markup("<pre><code>Error rendering Kubernetes POD Spec</pre></code>")
        html_dict['k8s'] = content

        return self.render_template(
            'airflow/ti_code.html',
            html_dict=html_dict,
            dag=dag,
            task_id=task_id,
            execution_date=execution_date,
            map_index=map_index,
            form=form,
            root=root,
            title=title,
        )

    @expose('/get_logs_with_metadata')
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_TASK_INSTANCE),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_TASK_LOG),
        ]
    )
    @action_logging
    @provide_session
    def get_logs_with_metadata(self, session=None):
        """Retrieve logs including metadata."""
        dag_id = request.args.get('dag_id')
        task_id = request.args.get('task_id')
        execution_date = request.args.get('execution_date')
        map_index = request.args.get('map_index', -1, type=int)
        try_number = request.args.get('try_number', type=int)
        metadata = request.args.get('metadata', '{}')
        response_format = request.args.get('format', 'json')

        # Validate JSON metadata
        try:
            metadata = json.loads(metadata)
            # metadata may be null
            if not metadata:
                metadata = {}
        except json.decoder.JSONDecodeError:
            return {"error": "Invalid JSON metadata"}, 400

        # Convert string datetime into actual datetime
        try:
            execution_date = timezone.parse(execution_date)
        except ValueError:
            error_message = (
                f'Given execution date, {execution_date}, could not be identified as a date. '
                'Example date format: 2015-11-16T14:34:15+00:00'
            )
            return {'error': error_message}, 400

        task_log_reader = TaskLogReader()
        if not task_log_reader.supports_read:
            return {
                "message": "Task log handler does not support read logs.",
                "error": True,
                "metadata": {"end_of_log": True},
            }

        ti = (
            session.query(models.TaskInstance)
            .filter_by(dag_id=dag_id, task_id=task_id, execution_date=execution_date, map_index=map_index)
            .first()
        )

        if ti is None:
            return {
                "message": "*** Task instance did not exist in the DB\n",
                "error": True,
                "metadata": {"end_of_log": True},
            }

        try:
            dag = get_airflow_app().dag_bag.get_dag(dag_id)
            if dag:
                ti.task = dag.get_task(ti.task_id)

            if response_format == 'json':
                logs, metadata = task_log_reader.read_log_chunks(ti, try_number, metadata)
                message = logs[0] if try_number is not None else logs
                return {"message": message, "metadata": metadata}

            metadata['download_logs'] = True
            attachment_filename = task_log_reader.render_log_filename(ti, try_number, session=session)
            log_stream = task_log_reader.read_log_stream(ti, try_number, metadata)
            return Response(
                response=log_stream,
                mimetype="text/plain",
                headers={"Content-Disposition": f"attachment; filename={attachment_filename}"},
            )
        except AttributeError as e:
            error_message = [f"Task log handler does not support read logs.\n{str(e)}\n"]
            metadata['end_of_log'] = True
            return {"message": error_message, "error": True, "metadata": metadata}

    @expose('/log')
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_TASK_INSTANCE),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_TASK_LOG),
        ]
    )
    @action_logging
    @provide_session
    def log(self, session=None):
        """Retrieve log."""
        dag_id = request.args.get('dag_id')
        task_id = request.args.get('task_id')
        map_index = request.args.get('map_index', -1, type=int)
        execution_date = request.args.get('execution_date')

        if execution_date:
            dttm = _safe_parse_datetime(execution_date)
        else:
            dttm = None

        form = DateTimeForm(data={'execution_date': dttm})
        dag_model = DagModel.get_dagmodel(dag_id)

        ti = (
            session.query(models.TaskInstance)
            .filter_by(dag_id=dag_id, task_id=task_id, execution_date=dttm, map_index=map_index)
            .first()
        )

        num_logs = 0
        if ti is not None:
            num_logs = ti.next_try_number - 1
            if ti.state in (State.UP_FOR_RESCHEDULE, State.DEFERRED):
                # Tasks in reschedule state decremented the try number
                num_logs += 1
        logs = [''] * num_logs
        root = request.args.get('root', '')
        return self.render_template(
            'airflow/ti_log.html',
            logs=logs,
            dag=dag_model,
            title="Log by attempts",
            dag_id=dag_id,
            task_id=task_id,
            execution_date=execution_date,
            map_index=map_index,
            form=form,
            root=root,
            wrapped=conf.getboolean('webserver', 'default_wrap'),
        )

    @expose('/redirect_to_external_log')
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_TASK_INSTANCE),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_TASK_LOG),
        ]
    )
    @action_logging
    @provide_session
    def redirect_to_external_log(self, session=None):
        """Redirects to external log."""
        dag_id = request.args.get('dag_id')
        task_id = request.args.get('task_id')
        execution_date = request.args.get('execution_date')
        dttm = _safe_parse_datetime(execution_date)
        map_index = request.args.get('map_index', -1, type=int)
        try_number = request.args.get('try_number', 1)

        ti = (
            session.query(models.TaskInstance)
            .filter_by(dag_id=dag_id, task_id=task_id, execution_date=dttm, map_index=map_index)
            .first()
        )

        if not ti:
            flash(f"Task [{dag_id}.{task_id}] does not exist", "error")
            return redirect(url_for('Airflow.index'))

        task_log_reader = TaskLogReader()
        if not task_log_reader.supports_external_link:
            flash("Task log handler does not support external links", "error")
            return redirect(url_for('Airflow.index'))

        handler = task_log_reader.log_handler
        url = handler.get_external_log_url(ti, try_number)
        return redirect(url)

    @expose('/task')
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_TASK_INSTANCE),
        ]
    )
    @action_logging
    @provide_session
    def task(self, session):
        """Retrieve task."""
        dag_id = request.args.get('dag_id')
        task_id = request.args.get('task_id')
        execution_date = request.args.get('execution_date')
        dttm = _safe_parse_datetime(execution_date)
        map_index = request.args.get('map_index', -1, type=int)
        form = DateTimeForm(data={'execution_date': dttm})
        root = request.args.get('root', '')
        dag = get_airflow_app().dag_bag.get_dag(dag_id)

        if not dag or task_id not in dag.task_ids:
            flash(f"Task [{dag_id}.{task_id}] doesn't seem to exist at the moment", "error")
            return redirect(url_for('Airflow.index'))
        task = copy.copy(dag.get_task(task_id))
        task.resolve_template_files()

        ti: Optional[TaskInstance] = (
            session.query(TaskInstance)
            .options(
                # HACK: Eager-load relationships. This is needed because
                # multiple properties mis-use provide_session() that destroys
                # the session object ti is bounded to.
                joinedload(TaskInstance.queued_by_job, innerjoin=False),
                joinedload(TaskInstance.trigger, innerjoin=False),
            )
            .filter_by(execution_date=dttm, dag_id=dag_id, task_id=task_id, map_index=map_index)
            .one_or_none()
        )
        if ti is None:
            ti_attrs: Optional[List[Tuple[str, Any]]] = None
        else:
            ti.refresh_from_task(task)
            ti_attrs_to_skip = [
                'dag_id',
                'key',
                'mark_success_url',
                'log',
                'log_url',
                'task',
            ]
            # Some fields on TI are deprecated, but we don't want those warnings here.
            with warnings.catch_warnings():
                warnings.simplefilter("ignore", DeprecationWarning)
                all_ti_attrs = (
                    (name, getattr(ti, name))
                    for name in dir(ti)
                    if not name.startswith("_") and name not in ti_attrs_to_skip
                )
            ti_attrs = sorted((name, attr) for name, attr in all_ti_attrs if not callable(attr))

        attr_renderers = wwwutils.get_attr_renderer()

        attrs_to_skip = getattr(task, 'HIDE_ATTRS_FROM_UI', set())

        def include_task_attrs(attr_name):
            return not (
                attr_name == 'HIDE_ATTRS_FROM_UI'
                or attr_name.startswith("_")
                or attr_name in attr_renderers
                or attr_name in attrs_to_skip
            )

        task_attrs = [
            (attr_name, attr)
            for attr_name, attr in (
                (attr_name, getattr(task, attr_name)) for attr_name in filter(include_task_attrs, dir(task))
            )
            if not callable(attr)
        ]

        # Color coding the special attributes that are code
        special_attrs_rendered = {
            attr_name: renderer(getattr(task, attr_name))
            for attr_name, renderer in attr_renderers.items()
            if hasattr(task, attr_name)
        }

        no_failed_deps_result = [
            (
                "Unknown",
                "All dependencies are met but the task instance is not running. In most "
                "cases this just means that the task will probably be scheduled soon "
                "unless:<br>\n- The scheduler is down or under heavy load<br>\n{}\n"
                "<br>\nIf this task instance does not start soon please contact your "
                "Airflow administrator for assistance.".format(
                    "- This task instance already ran and had it's state changed manually "
                    "(e.g. cleared in the UI)<br>"
                    if ti and ti.state == State.NONE
                    else ""
                ),
            )
        ]

        # Use the scheduler's context to figure out which dependencies are not met
        if ti is None:
            failed_dep_reasons: List[Tuple[str, str]] = []
        else:
            dep_context = DepContext(SCHEDULER_QUEUED_DEPS)
            failed_dep_reasons = [
                (dep.dep_name, dep.reason) for dep in ti.get_failed_dep_statuses(dep_context=dep_context)
            ]

        title = "Task Instance Details"
        return self.render_template(
            'airflow/task.html',
            task_attrs=task_attrs,
            ti_attrs=ti_attrs,
            failed_dep_reasons=failed_dep_reasons or no_failed_deps_result,
            task_id=task_id,
            execution_date=execution_date,
            map_index=map_index,
            special_attrs_rendered=special_attrs_rendered,
            form=form,
            root=root,
            dag=dag,
            title=title,
        )

    @expose('/xcom')
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_TASK_INSTANCE),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_XCOM),
        ]
    )
    @action_logging
    @provide_session
    def xcom(self, session=None):
        """Retrieve XCOM."""
        dag_id = request.args.get('dag_id')
        task_id = request.args.get('task_id')
        map_index = request.args.get('map_index', -1, type=int)
        # Carrying execution_date through, even though it's irrelevant for
        # this context
        execution_date = request.args.get('execution_date')
        dttm = _safe_parse_datetime(execution_date)

        form = DateTimeForm(data={'execution_date': dttm})
        root = request.args.get('root', '')
        dag = DagModel.get_dagmodel(dag_id)
        ti = session.query(TaskInstance).filter_by(dag_id=dag_id, task_id=task_id).first()

        if not ti:
            flash(f"Task [{dag_id}.{task_id}] doesn't seem to exist at the moment", "error")
            return redirect(url_for('Airflow.index'))

        xcomlist = (
            session.query(XCom)
            .filter_by(dag_id=dag_id, task_id=task_id, execution_date=dttm, map_index=map_index)
            .all()
        )

        attributes = []
        for xcom in xcomlist:
            if not xcom.key.startswith('_'):
                attributes.append((xcom.key, xcom.value))

        title = "XCom"
        return self.render_template(
            'airflow/xcom.html',
            attributes=attributes,
            task_id=task_id,
            execution_date=execution_date,
            map_index=map_index,
            form=form,
            root=root,
            dag=dag,
            title=title,
        )

    @expose('/run', methods=['POST'])
    @auth.has_access(
        [
            (permissions.ACTION_CAN_EDIT, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_CREATE, permissions.RESOURCE_TASK_INSTANCE),
        ]
    )
    @action_logging
    @provide_session
    def run(self, session=None):
        """Runs Task Instance."""
        dag_id = request.form.get('dag_id')
        task_id = request.form.get('task_id')
        dag_run_id = request.form.get('dag_run_id')
        map_index = request.args.get('map_index', -1, type=int)
        origin = get_safe_url(request.form.get('origin'))
        dag: DAG = get_airflow_app().dag_bag.get_dag(dag_id)
        task = dag.get_task(task_id)

        ignore_all_deps = request.form.get('ignore_all_deps') == "true"
        ignore_task_deps = request.form.get('ignore_task_deps') == "true"
        ignore_ti_state = request.form.get('ignore_ti_state') == "true"

        executor = ExecutorLoader.get_default_executor()

        if not getattr(executor, "supports_ad_hoc_ti_run", False):
            msg = "Only works with the Celery, CeleryKubernetes or Kubernetes executors"
            return redirect_or_json(origin, msg, "error", 400)

        dag_run = dag.get_dagrun(run_id=dag_run_id)
        ti = dag_run.get_task_instance(task_id=task.task_id, map_index=map_index)
        if not ti:
            msg = "Could not queue task instance for execution, task instance is missing"
            return redirect_or_json(origin, msg, "error", 400)

        ti.refresh_from_task(task)

        # Make sure the task instance can be run
        dep_context = DepContext(
            deps=RUNNING_DEPS,
            ignore_all_deps=ignore_all_deps,
            ignore_task_deps=ignore_task_deps,
            ignore_ti_state=ignore_ti_state,
        )
        failed_deps = list(ti.get_failed_dep_statuses(dep_context=dep_context))
        if failed_deps:
            failed_deps_str = ", ".join(f"{dep.dep_name}: {dep.reason}" for dep in failed_deps)
            msg = f"Could not queue task instance for execution, dependencies not met: {failed_deps_str}"
            return redirect_or_json(origin, msg, "error", 400)

        executor.job_id = "manual"
        executor.start()
        executor.queue_task_instance(
            ti,
            ignore_all_deps=ignore_all_deps,
            ignore_task_deps=ignore_task_deps,
            ignore_ti_state=ignore_ti_state,
        )
        executor.heartbeat()
        ti.queued_dttm = timezone.utcnow()
        session.merge(ti)
        msg = f"Sent {ti} to the message queue, it should start any moment now."
        return redirect_or_json(origin, msg)

    @expose('/delete', methods=['POST'])
    @auth.has_access(
        [
            (permissions.ACTION_CAN_DELETE, permissions.RESOURCE_DAG),
        ]
    )
    @action_logging
    def delete(self):
        """Deletes DAG."""
        from airflow.api.common import delete_dag
        from airflow.exceptions import DagNotFound

        dag_id = request.values.get('dag_id')
        origin = get_safe_url(request.values.get('origin'))
        redirect_url = get_safe_url(request.values.get('redirect_url'))

        try:
            delete_dag.delete_dag(dag_id)
        except DagNotFound:
            flash(f"DAG with id {dag_id} not found. Cannot delete", 'error')
            return redirect(redirect_url)
        except AirflowException:
            flash(
                f"Cannot delete DAG with id {dag_id} because some task instances of the DAG "
                "are still running. Please mark the  task instances as "
                "failed/succeeded before deleting the DAG",
                "error",
            )
            return redirect(redirect_url)

        flash(f"Deleting DAG with id {dag_id}. May take a couple minutes to fully disappear.")

        # Upon success return to origin.
        return redirect(origin)

    @expose('/trigger', methods=['POST', 'GET'])
    @auth.has_access(
        [
            (permissions.ACTION_CAN_EDIT, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_CREATE, permissions.RESOURCE_DAG_RUN),
        ]
    )
    @action_logging
    @provide_session
    def trigger(self, session=None):
        """Triggers DAG Run."""
        dag_id = request.values.get('dag_id')
        run_id = request.values.get('run_id')
        origin = get_safe_url(request.values.get('origin'))
        unpause = request.values.get('unpause')
        request_conf = request.values.get('conf')
        request_execution_date = request.values.get('execution_date', default=timezone.utcnow().isoformat())
        is_dag_run_conf_overrides_params = conf.getboolean('core', 'dag_run_conf_overrides_params')
        dag = get_airflow_app().dag_bag.get_dag(dag_id)
        dag_orm = session.query(models.DagModel).filter(models.DagModel.dag_id == dag_id).first()
        if not dag_orm:
            flash(f"Cannot find dag {dag_id}")
            return redirect(origin)

        if dag_orm.has_import_errors:
            flash(f"Cannot create dagruns because the dag {dag_id} has import errors", "error")
            return redirect(origin)

        if request.method == 'GET':
            # Populate conf textarea with conf requests parameter, or dag.params
            default_conf = ''

            doc_md = wwwutils.wrapped_markdown(getattr(dag, 'doc_md', None))
            form = DateTimeForm(data={'execution_date': request_execution_date})

            if request_conf:
                default_conf = request_conf
            else:
                try:
                    default_conf = json.dumps(
                        {str(k): v.resolve(suppress_exception=True) for k, v in dag.params.items()}, indent=4
                    )
                except TypeError:
                    flash("Could not pre-populate conf field due to non-JSON-serializable data-types")
            return self.render_template(
                'airflow/trigger.html',
                dag_id=dag_id,
                origin=origin,
                conf=default_conf,
                doc_md=doc_md,
                form=form,
                is_dag_run_conf_overrides_params=is_dag_run_conf_overrides_params,
            )

        try:
            execution_date = timezone.parse(request_execution_date)
        except ParserError:
            flash("Invalid execution date", "error")
            form = DateTimeForm(data={'execution_date': timezone.utcnow().isoformat()})
            return self.render_template(
                'airflow/trigger.html',
                dag_id=dag_id,
                origin=origin,
                conf=request_conf,
                form=form,
                is_dag_run_conf_overrides_params=is_dag_run_conf_overrides_params,
            )
        # if run_id is not None, filter dag runs based on run id and ignore execution date
        dr = DagRun.find_duplicate(dag_id=dag_id, run_id=run_id, execution_date=execution_date)
        if dr:
            flash(f"The run_id {dr.run_id} already exists", "error")
            return redirect(origin)

        # Flash a warning when slash is used, but still allow it to continue on.
        if run_id and "/" in run_id:
            flash(
                "Using forward slash ('/') in a DAG run ID is deprecated. Note that this character "
                "also makes the run impossible to retrieve via Airflow's REST API.",
                "warning",
            )

        run_conf = {}
        if request_conf:
            try:
                run_conf = json.loads(request_conf)
                if not isinstance(run_conf, dict):
                    flash("Invalid JSON configuration, must be a dict", "error")
                    form = DateTimeForm(data={'execution_date': execution_date})
                    return self.render_template(
                        'airflow/trigger.html',
                        dag_id=dag_id,
                        origin=origin,
                        conf=request_conf,
                        form=form,
                        is_dag_run_conf_overrides_params=is_dag_run_conf_overrides_params,
                    )
            except json.decoder.JSONDecodeError:
                flash("Invalid JSON configuration, not parseable", "error")
                form = DateTimeForm(data={'execution_date': execution_date})
                return self.render_template(
                    'airflow/trigger.html',
                    dag_id=dag_id,
                    origin=origin,
                    conf=request_conf,
                    form=form,
                    is_dag_run_conf_overrides_params=is_dag_run_conf_overrides_params,
                )

        if unpause and dag.is_paused:
            models.DagModel.get_dagmodel(dag_id).set_is_paused(is_paused=False)

        try:
            dag.create_dagrun(
                run_type=DagRunType.MANUAL,
                execution_date=execution_date,
                data_interval=dag.timetable.infer_manual_data_interval(run_after=execution_date),
                state=State.QUEUED,
                conf=run_conf,
                external_trigger=True,
                dag_hash=get_airflow_app().dag_bag.dags_hash.get(dag_id),
                run_id=run_id,
            )
        except (ValueError, ParamValidationError) as ve:
            flash(f"{ve}", "error")
            form = DateTimeForm(data={'execution_date': execution_date})
            return self.render_template(
                'airflow/trigger.html',
                dag_id=dag_id,
                origin=origin,
                conf=request_conf,
                form=form,
                is_dag_run_conf_overrides_params=is_dag_run_conf_overrides_params,
            )

        flash(f"Triggered {dag_id}, it should start any moment now.")
        return redirect(origin)

    def _clear_dag_tis(
        self,
        dag: DAG,
        start_date,
        end_date,
        origin,
        task_ids=None,
        recursive=False,
        confirmed=False,
        only_failed=False,
    ):
        if confirmed:
            count = dag.clear(
                start_date=start_date,
                end_date=end_date,
                task_ids=task_ids,
                include_subdags=recursive,
                include_parentdag=recursive,
                only_failed=only_failed,
            )

            msg = f"{count} task instances have been cleared"
            return redirect_or_json(origin, msg)

        try:
            tis = dag.clear(
                start_date=start_date,
                end_date=end_date,
                task_ids=task_ids,
                include_subdags=recursive,
                include_parentdag=recursive,
                only_failed=only_failed,
                dry_run=True,
            )
        except AirflowException as ex:
            return redirect_or_json(origin, msg=str(ex), status="error", status_code=500)

        assert isinstance(tis, collections.abc.Iterable)
        details = [str(t) for t in tis]

        if not details:
            return redirect_or_json(origin, "No task instances to clear", status="error", status_code=404)
        elif request.headers.get('Accept') == 'application/json':
            return htmlsafe_json_dumps(details, separators=(',', ':'))
        return self.render_template(
            'airflow/confirm.html',
            endpoint=None,
            message="Task instances you are about to clear:",
            details="\n".join(details),
        )

    @expose('/clear', methods=['POST'])
    @auth.has_access(
        [
            (permissions.ACTION_CAN_EDIT, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_DELETE, permissions.RESOURCE_TASK_INSTANCE),
        ]
    )
    @action_logging
    def clear(self):
        """Clears the Dag."""
        dag_id = request.form.get('dag_id')
        task_id = request.form.get('task_id')
        origin = get_safe_url(request.form.get('origin'))
        dag = get_airflow_app().dag_bag.get_dag(dag_id)

        if 'map_index' not in request.form:
            map_indexes: Optional[List[int]] = None
        else:
            map_indexes = request.form.getlist('map_index', type=int)

        execution_date = request.form.get('execution_date')
        execution_date = _safe_parse_datetime(execution_date)
        confirmed = request.form.get('confirmed') == "true"
        upstream = request.form.get('upstream') == "true"
        downstream = request.form.get('downstream') == "true"
        future = request.form.get('future') == "true"
        past = request.form.get('past') == "true"
        recursive = request.form.get('recursive') == "true"
        only_failed = request.form.get('only_failed') == "true"

        task_ids: List[Union[str, Tuple[str, int]]]
        if map_indexes is None:
            task_ids = [task_id]
        else:
            task_ids = [(task_id, map_index) for map_index in map_indexes]

        dag = dag.partial_subset(
            task_ids_or_regex=[task_id],
            include_downstream=downstream,
            include_upstream=upstream,
        )

        if len(dag.task_dict) > 1:
            # If we had upstream/downstream etc then also include those!
            task_ids.extend(tid for tid in dag.task_dict if tid != task_id)

        end_date = execution_date if not future else None
        start_date = execution_date if not past else None

        return self._clear_dag_tis(
            dag,
            start_date,
            end_date,
            origin,
            task_ids=task_ids,
            recursive=recursive,
            confirmed=confirmed,
            only_failed=only_failed,
        )

    @expose('/dagrun_clear', methods=['POST'])
    @auth.has_access(
        [
            (permissions.ACTION_CAN_EDIT, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_DELETE, permissions.RESOURCE_TASK_INSTANCE),
        ]
    )
    @action_logging
    def dagrun_clear(self):
        """Clears the DagRun"""
        dag_id = request.form.get('dag_id')
        dag_run_id = request.form.get('dag_run_id')
        confirmed = request.form.get('confirmed') == "true"

        dag = get_airflow_app().dag_bag.get_dag(dag_id)
        dr = dag.get_dagrun(run_id=dag_run_id)
        start_date = dr.logical_date
        end_date = dr.logical_date

        return self._clear_dag_tis(
            dag,
            start_date,
            end_date,
            origin=None,
            recursive=True,
            confirmed=confirmed,
        )

    @expose('/blocked', methods=['POST'])
    @auth.has_access(
        [
            (permissions.ACTION_CAN_EDIT, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG_RUN),
        ]
    )
    @provide_session
    def blocked(self, session=None):
        """Mark Dag Blocked."""
        allowed_dag_ids = get_airflow_app().appbuilder.sm.get_accessible_dag_ids(g.user)

        # Filter by post parameters
        selected_dag_ids = {unquote(dag_id) for dag_id in request.form.getlist('dag_ids') if dag_id}

        if selected_dag_ids:
            filter_dag_ids = selected_dag_ids.intersection(allowed_dag_ids)
        else:
            filter_dag_ids = allowed_dag_ids

        if not filter_dag_ids:
            return wwwutils.json_response([])

        dags = (
            session.query(DagRun.dag_id, sqla.func.count(DagRun.id))
            .filter(DagRun.state == State.RUNNING)
            .filter(DagRun.dag_id.in_(filter_dag_ids))
            .group_by(DagRun.dag_id)
        )

        payload = []
        for dag_id, active_dag_runs in dags:
            max_active_runs = 0
            dag = get_airflow_app().dag_bag.get_dag(dag_id)
            if dag:
                # TODO: Make max_active_runs a column so we can query for it directly
                max_active_runs = dag.max_active_runs
            payload.append(
                {
                    'dag_id': dag_id,
                    'active_dag_run': active_dag_runs,
                    'max_active_runs': max_active_runs,
                }
            )
        return wwwutils.json_response(payload)

    def _mark_dagrun_state_as_failed(self, dag_id, dag_run_id, confirmed):
        if not dag_run_id:
            return {'status': 'error', 'message': 'Invalid dag_run_id'}

        dag = get_airflow_app().dag_bag.get_dag(dag_id)

        if not dag:
            return {'status': 'error', 'message': f'Cannot find DAG: {dag_id}'}

        new_dag_state = set_dag_run_state_to_failed(dag=dag, run_id=dag_run_id, commit=confirmed)

        if confirmed:
            return {'status': 'success', 'message': f'Marked failed on {len(new_dag_state)} task instances'}
        else:
            details = [str(t) for t in new_dag_state]

            return htmlsafe_json_dumps(details, separators=(',', ':'))

    def _mark_dagrun_state_as_success(self, dag_id, dag_run_id, confirmed):
        if not dag_run_id:
            return {'status': 'error', 'message': 'Invalid dag_run_id'}

        dag = get_airflow_app().dag_bag.get_dag(dag_id)

        if not dag:
            return {'status': 'error', 'message': f'Cannot find DAG: {dag_id}'}

        new_dag_state = set_dag_run_state_to_success(dag=dag, run_id=dag_run_id, commit=confirmed)

        if confirmed:
            return {'status': 'success', 'message': f'Marked success on {len(new_dag_state)} task instances'}
        else:
            details = [str(t) for t in new_dag_state]

            return htmlsafe_json_dumps(details, separators=(',', ':'))

    def _mark_dagrun_state_as_queued(self, dag_id: str, dag_run_id: str, confirmed: bool):
        if not dag_run_id:
            return {'status': 'error', 'message': 'Invalid dag_run_id'}

        dag = get_airflow_app().dag_bag.get_dag(dag_id)

        if not dag:
            return {'status': 'error', 'message': f'Cannot find DAG: {dag_id}'}

        new_dag_state = set_dag_run_state_to_queued(dag=dag, run_id=dag_run_id, commit=confirmed)

        if confirmed:
            return {'status': 'success', 'message': 'Marked the DagRun as queued.'}

        else:
            details = [str(t) for t in new_dag_state]

            return htmlsafe_json_dumps(details, separators=(',', ':'))

    @expose('/dagrun_failed', methods=['POST'])
    @auth.has_access(
        [
            (permissions.ACTION_CAN_EDIT, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_EDIT, permissions.RESOURCE_DAG_RUN),
        ]
    )
    @action_logging
    def dagrun_failed(self):
        """Mark DagRun failed."""
        dag_id = request.form.get('dag_id')
        dag_run_id = request.form.get('dag_run_id')
        confirmed = request.form.get('confirmed') == 'true'
        return self._mark_dagrun_state_as_failed(dag_id, dag_run_id, confirmed)

    @expose('/dagrun_success', methods=['POST'])
    @auth.has_access(
        [
            (permissions.ACTION_CAN_EDIT, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_EDIT, permissions.RESOURCE_DAG_RUN),
        ]
    )
    @action_logging
    def dagrun_success(self):
        """Mark DagRun success"""
        dag_id = request.form.get('dag_id')
        dag_run_id = request.form.get('dag_run_id')
        confirmed = request.form.get('confirmed') == 'true'
        return self._mark_dagrun_state_as_success(dag_id, dag_run_id, confirmed)

    @expose('/dagrun_queued', methods=['POST'])
    @auth.has_access(
        [
            (permissions.ACTION_CAN_EDIT, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_EDIT, permissions.RESOURCE_DAG_RUN),
        ]
    )
    @action_logging
    def dagrun_queued(self):
        """Queue DagRun so tasks that haven't run yet can be started."""
        dag_id = request.form.get('dag_id')
        dag_run_id = request.form.get('dag_run_id')
        confirmed = request.form.get('confirmed') == 'true'
        return self._mark_dagrun_state_as_queued(dag_id, dag_run_id, confirmed)

    @expose("/dagrun_details")
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG_RUN),
        ]
    )
    @action_logging
    @provide_session
    def dagrun_details(self, session=None):
        """Retrieve DAG Run details."""
        dag_id = request.args.get("dag_id")
        run_id = request.args.get("run_id")

        dag = get_airflow_app().dag_bag.get_dag(dag_id)
        dag_run: Optional[DagRun] = (
            session.query(DagRun).filter(DagRun.dag_id == dag_id, DagRun.run_id == run_id).one_or_none()
        )
        redirect_url = get_safe_url(request.values.get('redirect_url'))

        if dag_run is None:
            flash(f"No DAG run found for DAG id {dag_id} and run id {run_id}", "error")
            return redirect(redirect_url or url_for('Airflow.index'))
        else:
            try:
                duration = dag_run.end_date - dag_run.start_date
            except TypeError:
                # Raised if end_date is None e.g. when DAG is still running
                duration = None

            dagrun_attributes = [
                ("Logical date", wwwutils.datetime_html(dag_run.execution_date)),
                ("Queued at", wwwutils.datetime_html(dag_run.queued_at)),
                ("Start date", wwwutils.datetime_html(dag_run.start_date)),
                ("End date", wwwutils.datetime_html(dag_run.end_date)),
                ("Duration", str(duration)),
                ("Current state", wwwutils.state_token(dag_run.state)),
                ("Run type", dag_run.run_type),
                ("Externally triggered", dag_run.external_trigger),
                ("Config", wwwutils.json_render(dag_run.conf, lexers.JsonLexer)),
            ]

            return self.render_template(
                "airflow/dagrun_details.html",
                dag=dag,
                dag_id=dag_id,
                run_id=run_id,
                execution_date=dag_run.execution_date.isoformat(),
                dagrun_attributes=dagrun_attributes,
            )

    def _mark_task_instance_state(
        self,
        *,
        dag_id: str,
        run_id: str,
        task_id: str,
        map_indexes: Optional[List[int]],
        origin: str,
        upstream: bool,
        downstream: bool,
        future: bool,
        past: bool,
        state: TaskInstanceState,
    ):
        dag: DAG = get_airflow_app().dag_bag.get_dag(dag_id)

        if not run_id:
            flash(f"Cannot mark tasks as {state}, seem that DAG {dag_id} has never run", "error")
            return redirect(origin)

        altered = dag.set_task_instance_state(
            task_id=task_id,
            map_indexes=map_indexes,
            run_id=run_id,
            state=state,
            upstream=upstream,
            downstream=downstream,
            future=future,
            past=past,
        )

        flash(f"Marked {state} on {len(altered)} task instances")
        return redirect(origin)

    @expose('/confirm', methods=['GET'])
    @auth.has_access(
        [
            (permissions.ACTION_CAN_EDIT, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_EDIT, permissions.RESOURCE_TASK_INSTANCE),
        ]
    )
    @action_logging
    def confirm(self):
        """Show confirmation page for marking tasks as success or failed."""
        args = request.args
        dag_id = args.get('dag_id')
        task_id = args.get('task_id')
        dag_run_id = args.get('dag_run_id')
        state = args.get('state')
        origin = args.get('origin')

        if 'map_index' not in args:
            map_indexes: Optional[List[int]] = None
        else:
            map_indexes = args.getlist('map_index', type=int)

        upstream = to_boolean(args.get('upstream'))
        downstream = to_boolean(args.get('downstream'))
        future = to_boolean(args.get('future'))
        past = to_boolean(args.get('past'))
        origin = origin or url_for('Airflow.index')

        dag = get_airflow_app().dag_bag.get_dag(dag_id)
        if not dag:
            msg = f'DAG {dag_id} not found'
            return redirect_or_json(origin, msg, status='error', status_code=404)

        try:
            task = dag.get_task(task_id)
        except airflow.exceptions.TaskNotFound:
            msg = f"Task {task_id} not found"
            return redirect_or_json(origin, msg, status='error', status_code=404)

        task.dag = dag

        if state not in (
            'success',
            'failed',
        ):
            msg = f"Invalid state {state}, must be either 'success' or 'failed'"
            return redirect_or_json(origin, msg, status='error', status_code=400)

        latest_execution_date = dag.get_latest_execution_date()
        if not latest_execution_date:
            msg = f"Cannot mark tasks as {state}, seem that dag {dag_id} has never run"
            return redirect_or_json(origin, msg, status='error', status_code=400)

        if map_indexes is None:
            tasks: Union[List[Operator], List[Tuple[Operator, int]]] = [task]
        else:
            tasks = [(task, map_index) for map_index in map_indexes]

        to_be_altered = set_state(
            tasks=tasks,
            run_id=dag_run_id,
            upstream=upstream,
            downstream=downstream,
            future=future,
            past=past,
            state=state,
            commit=False,
        )

        if request.headers.get('Accept') == 'application/json':
            details = [str(t) for t in to_be_altered]
            return htmlsafe_json_dumps(details, separators=(',', ':'))

        details = "\n".join(str(t) for t in to_be_altered)

        response = self.render_template(
            "airflow/confirm.html",
            endpoint=url_for(f'Airflow.{state}'),
            message=f"Task instances you are about to mark as {state}:",
            details=details,
        )

        return response

    @expose('/failed', methods=['POST'])
    @auth.has_access(
        [
            (permissions.ACTION_CAN_EDIT, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_EDIT, permissions.RESOURCE_TASK_INSTANCE),
        ]
    )
    @action_logging
    def failed(self):
        """Mark task as failed."""
        args = request.form
        dag_id = args.get('dag_id')
        task_id = args.get('task_id')
        run_id = args.get('dag_run_id')

        if 'map_index' not in args:
            map_indexes: Optional[List[int]] = None
        else:
            map_indexes = args.getlist('map_index', type=int)

        origin = get_safe_url(args.get('origin'))
        upstream = to_boolean(args.get('upstream'))
        downstream = to_boolean(args.get('downstream'))
        future = to_boolean(args.get('future'))
        past = to_boolean(args.get('past'))

        return self._mark_task_instance_state(
            dag_id=dag_id,
            run_id=run_id,
            task_id=task_id,
            map_indexes=map_indexes,
            origin=origin,
            upstream=upstream,
            downstream=downstream,
            future=future,
            past=past,
            state=TaskInstanceState.FAILED,
        )

    @expose('/success', methods=['POST'])
    @auth.has_access(
        [
            (permissions.ACTION_CAN_EDIT, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_EDIT, permissions.RESOURCE_TASK_INSTANCE),
        ]
    )
    @action_logging
    def success(self):
        """Mark task as success."""
        args = request.form
        dag_id = args.get('dag_id')
        task_id = args.get('task_id')
        run_id = args.get('dag_run_id')

        if 'map_index' not in args:
            map_indexes: Optional[List[int]] = None
        else:
            map_indexes = args.getlist('map_index', type=int)

        origin = get_safe_url(args.get('origin'))
        upstream = to_boolean(args.get('upstream'))
        downstream = to_boolean(args.get('downstream'))
        future = to_boolean(args.get('future'))
        past = to_boolean(args.get('past'))

        return self._mark_task_instance_state(
            dag_id=dag_id,
            run_id=run_id,
            task_id=task_id,
            map_indexes=map_indexes,
            origin=origin,
            upstream=upstream,
            downstream=downstream,
            future=future,
            past=past,
            state=TaskInstanceState.SUCCESS,
        )

    @expose('/dags/<string:dag_id>')
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_TASK_INSTANCE),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_TASK_LOG),
        ]
    )
    @gzipped
    @action_logging
    def dag(self, dag_id):
        """Redirect to default DAG view."""
        return redirect(url_for('Airflow.grid', dag_id=dag_id, **request.args))

    @expose('/legacy_tree')
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_TASK_INSTANCE),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_TASK_LOG),
        ]
    )
    @gzipped
    @action_logging
    def legacy_tree(self):
        """Redirect to the replacement - grid view."""
        return redirect(url_for('Airflow.grid', **request.args))

    @expose('/tree')
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_TASK_INSTANCE),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_TASK_LOG),
        ]
    )
    @gzipped
    @action_logging
    def tree(self):
        """Redirect to the replacement - grid view. Kept for backwards compatibility."""
        return redirect(url_for('Airflow.grid', **request.args))

    @expose('/dags/<string:dag_id>/grid')
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_TASK_INSTANCE),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_TASK_LOG),
        ]
    )
    @gzipped
    @action_logging
    @provide_session
    def grid(self, dag_id, session=None):
        """Get Dag's grid view."""
        dag = get_airflow_app().dag_bag.get_dag(dag_id, session=session)
        dag_model = DagModel.get_dagmodel(dag_id, session=session)
        if not dag:
            flash(f'DAG "{dag_id}" seems to be missing from DagBag.', "error")
            return redirect(url_for('Airflow.index'))
        wwwutils.check_import_errors(dag.fileloc, session)
        wwwutils.check_dag_warnings(dag.dag_id, session)

        root = request.args.get('root')
        if root:
            dag = dag.partial_subset(task_ids_or_regex=root, include_downstream=False, include_upstream=True)

        num_runs = request.args.get('num_runs', type=int)
        if num_runs is None:
            num_runs = conf.getint('webserver', 'default_dag_run_display_number')

        doc_md = wwwutils.wrapped_markdown(getattr(dag, 'doc_md', None))

        task_log_reader = TaskLogReader()
        if task_log_reader.supports_external_link:
            external_log_name = task_log_reader.log_handler.log_name
        else:
            external_log_name = None

        default_dag_run_display_number = conf.getint('webserver', 'default_dag_run_display_number')

        num_runs_options = [5, 25, 50, 100, 365]

        if default_dag_run_display_number not in num_runs_options:
            insort_left(num_runs_options, default_dag_run_display_number)

        return self.render_template(
            'airflow/grid.html',
            root=root,
            dag=dag,
            doc_md=doc_md,
            num_runs=num_runs,
            show_external_log_redirect=task_log_reader.supports_external_link,
            external_log_name=external_log_name,
            dag_model=dag_model,
            auto_refresh_interval=conf.getint('webserver', 'auto_refresh_interval'),
            default_dag_run_display_number=default_dag_run_display_number,
            filters_drop_down_values=htmlsafe_json_dumps(
                {
                    "taskStates": [state.value for state in TaskInstanceState],
                    "dagStates": [state.value for state in State.dag_states],
                    "runTypes": [run_type.value for run_type in DagRunType],
                    "numRuns": num_runs_options,
                }
            ),
        )

    @expose('/calendar')
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_TASK_INSTANCE),
        ]
    )
    @gzipped
    @action_logging
    def legacy_calendar(self):
        """Redirect from url param."""
        return redirect(url_for('Airflow.calendar', **request.args))

    @expose('/dags/<string:dag_id>/calendar')
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_TASK_INSTANCE),
        ]
    )
    @gzipped
    @action_logging
    @provide_session
    def calendar(self, dag_id, session=None):
        """Get DAG runs as calendar"""

        def _convert_to_date(session, column):
            """Convert column to date."""
            if session.bind.dialect.name == 'mssql':
                return column.cast(Date)
            else:
                return func.date(column)

        dag = get_airflow_app().dag_bag.get_dag(dag_id, session=session)
        dag_model = DagModel.get_dagmodel(dag_id, session=session)
        if not dag:
            flash(f'DAG "{dag_id}" seems to be missing from DagBag.', "error")
            return redirect(url_for('Airflow.index'))

        wwwutils.check_import_errors(dag.fileloc, session)
        wwwutils.check_dag_warnings(dag.dag_id, session)

        root = request.args.get('root')
        if root:
            dag = dag.partial_subset(task_ids_or_regex=root, include_downstream=False, include_upstream=True)

        dag_states = (
            session.query(
                (_convert_to_date(session, DagRun.execution_date)).label('date'),
                DagRun.state,
                func.max(DagRun.data_interval_start).label('data_interval_start'),
                func.max(DagRun.data_interval_end).label('data_interval_end'),
                func.count('*').label('count'),
            )
            .filter(DagRun.dag_id == dag.dag_id)
            .group_by(_convert_to_date(session, DagRun.execution_date), DagRun.state)
            .order_by(_convert_to_date(session, DagRun.execution_date).asc())
            .all()
        )

        data_dag_states = [
            {
                # DATE() in SQLite and MySQL behave differently:
                # SQLite returns a string, MySQL returns a date.
                'date': dr.date if isinstance(dr.date, str) else dr.date.isoformat(),
                'state': dr.state,
                'count': dr.count,
            }
            for dr in dag_states
        ]

        if dag_states and dag_states[-1].data_interval_start and dag_states[-1].data_interval_end:
            last_automated_data_interval = DataInterval(
                timezone.coerce_datetime(dag_states[-1].data_interval_start),
                timezone.coerce_datetime(dag_states[-1].data_interval_end),
            )

            year = last_automated_data_interval.end.year
            restriction = TimeRestriction(dag.start_date, dag.end_date, False)
            dates = collections.Counter()

            if isinstance(dag.timetable, CronDataIntervalTimetable):
                for next in croniter(
                    dag.timetable.summary, start_time=last_automated_data_interval.end, ret_type=datetime
                ):
                    if next is None:
                        break
                    if next.year != year:
                        break
                    if dag.end_date and next > dag.end_date:
                        break
                    dates[next.date()] += 1
            else:
                while True:
                    info = dag.timetable.next_dagrun_info(
                        last_automated_data_interval=last_automated_data_interval, restriction=restriction
                    )
                    if info is None:
                        break
                    if info.logical_date.year != year:
                        break
                    last_automated_data_interval = info.data_interval
                    dates[info.logical_date] += 1

            data_dag_states.extend(
                {'date': date.isoformat(), 'state': 'planned', 'count': count}
                for (date, count) in dates.items()
            )

        now = DateTime.utcnow()

        data = {
            'dag_states': data_dag_states,
            'start_date': (dag.start_date or DateTime.utcnow()).date().isoformat(),
            'end_date': (dag.end_date or now).date().isoformat(),
        }

        doc_md = wwwutils.wrapped_markdown(getattr(dag, 'doc_md', None))

        # avoid spaces to reduce payload size
        data = htmlsafe_json_dumps(data, separators=(',', ':'))

        return self.render_template(
            'airflow/calendar.html',
            dag=dag,
            doc_md=doc_md,
            data=data,
            root=root,
            dag_model=dag_model,
        )

    @expose('/graph')
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_TASK_INSTANCE),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_TASK_LOG),
        ]
    )
    @gzipped
    @action_logging
    def legacy_graph(self):
        """Redirect from url param."""
        return redirect(url_for('Airflow.graph', **request.args))

    @expose('/dags/<string:dag_id>/graph')
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_TASK_INSTANCE),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_TASK_LOG),
        ]
    )
    @gzipped
    @action_logging
    @provide_session
    def graph(self, dag_id, session=None):
        """Get DAG as Graph."""
        dag = get_airflow_app().dag_bag.get_dag(dag_id, session=session)
        dag_model = DagModel.get_dagmodel(dag_id, session=session)
        if not dag:
            flash(f'DAG "{dag_id}" seems to be missing.', "error")
            return redirect(url_for('Airflow.index'))

        wwwutils.check_import_errors(dag.fileloc, session)
        wwwutils.check_dag_warnings(dag.dag_id, session)

        root = request.args.get('root')
        if root:
            dag = dag.partial_subset(task_ids_or_regex=root, include_upstream=True, include_downstream=False)
        arrange = request.args.get('arrange', dag.orientation)

        nodes = task_group_to_dict(dag.task_group)
        edges = dag_edges(dag)

        dt_nr_dr_data = get_date_time_num_runs_dag_runs_form_data(request, session, dag)

        dt_nr_dr_data['arrange'] = arrange
        dttm = dt_nr_dr_data['dttm']
        dag_run = dag.get_dagrun(execution_date=dttm)
        dag_run_id = dag_run.run_id if dag_run else None

        class GraphForm(DateTimeWithNumRunsWithDagRunsForm):
            """Graph Form class."""

            arrange = SelectField(
                "Layout",
                choices=(
                    ('LR', "Left > Right"),
                    ('RL', "Right > Left"),
                    ('TB', "Top > Bottom"),
                    ('BT', "Bottom > Top"),
                ),
            )

        form = GraphForm(data=dt_nr_dr_data)
        form.execution_date.choices = dt_nr_dr_data['dr_choices']

        task_instances = {
            ti.task_id: wwwutils.get_instance_with_map(ti, session)
            for ti in dag.get_task_instances(dttm, dttm)
        }
        tasks = {
            t.task_id: {
                'dag_id': t.dag_id,
                'task_type': t.task_type,
                'extra_links': t.extra_links,
                'is_mapped': t.is_mapped,
            }
            for t in dag.tasks
        }
        if not tasks:
            flash("No tasks found", "error")
        session.commit()
        doc_md = wwwutils.wrapped_markdown(getattr(dag, 'doc_md', None))

        task_log_reader = TaskLogReader()
        if task_log_reader.supports_external_link:
            external_log_name = task_log_reader.log_handler.log_name
        else:
            external_log_name = None

        return self.render_template(
            'airflow/graph.html',
            dag=dag,
            form=form,
            width=request.args.get('width', "100%"),
            height=request.args.get('height', "800"),
            dag_run_id=dag_run_id,
            execution_date=dttm.isoformat(),
            state_token=wwwutils.state_token(dt_nr_dr_data['dr_state']),
            doc_md=doc_md,
            arrange=arrange,
            operators=sorted({op.task_type: op for op in dag.tasks}.values(), key=lambda x: x.task_type),
            root=root or '',
            task_instances=task_instances,
            tasks=tasks,
            nodes=nodes,
            edges=edges,
            show_external_log_redirect=task_log_reader.supports_external_link,
            external_log_name=external_log_name,
            dag_run_state=dt_nr_dr_data['dr_state'],
            dag_model=dag_model,
            auto_refresh_interval=conf.getint('webserver', 'auto_refresh_interval'),
        )

    @expose('/duration')
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_TASK_INSTANCE),
        ]
    )
    @action_logging
    def legacy_duration(self):
        """Redirect from url param."""
        return redirect(url_for('Airflow.duration', **request.args))

    @expose('/dags/<string:dag_id>/duration')
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_TASK_INSTANCE),
        ]
    )
    @action_logging
    @provide_session
    def duration(self, dag_id, session=None):
        """Get Dag as duration graph."""
        dag = get_airflow_app().dag_bag.get_dag(dag_id, session=session)
        dag_model = DagModel.get_dagmodel(dag_id, session=session)
        if not dag:
            flash(f'DAG "{dag_id}" seems to be missing.', "error")
            return redirect(url_for('Airflow.index'))

        wwwutils.check_import_errors(dag.fileloc, session)
        wwwutils.check_dag_warnings(dag.dag_id, session)

        default_dag_run = conf.getint('webserver', 'default_dag_run_display_number')
        base_date = request.args.get('base_date')
        num_runs = request.args.get('num_runs', default=default_dag_run, type=int)

        if base_date:
            base_date = _safe_parse_datetime(base_date)
        else:
            base_date = dag.get_latest_execution_date() or timezone.utcnow()

        root = request.args.get('root')
        if root:
            dag = dag.partial_subset(task_ids_or_regex=root, include_upstream=True, include_downstream=False)
        chart_height = wwwutils.get_chart_height(dag)
        chart = nvd3.lineChart(
            name="lineChart",
            x_custom_format=True,
            x_axis_date=True,
            x_axis_format=LINECHART_X_AXIS_TICKFORMAT,
            height=chart_height,
            chart_attr=self.line_chart_attr,
        )
        cum_chart = nvd3.lineChart(
            name="cumLineChart",
            x_custom_format=True,
            x_axis_date=True,
            x_axis_format=LINECHART_X_AXIS_TICKFORMAT,
            height=chart_height,
            chart_attr=self.line_chart_attr,
        )

        y_points = defaultdict(list)
        x_points = defaultdict(list)
        cumulative_y = defaultdict(list)

        task_instances = dag.get_task_instances_before(base_date, num_runs, session=session)
        if task_instances:
            min_date = task_instances[0].execution_date
        else:
            min_date = timezone.utc_epoch()
        ti_fails = (
            session.query(TaskFail)
            .join(TaskFail.dag_run)
            .filter(
                TaskFail.dag_id == dag.dag_id,
                DagRun.execution_date >= min_date,
                DagRun.execution_date <= base_date,
            )
        )
        if dag.partial:
            ti_fails = ti_fails.filter(TaskFail.task_id.in_([t.task_id for t in dag.tasks]))

        fails_totals = defaultdict(int)
        for failed_task_instance in ti_fails:
            dict_key = (
                failed_task_instance.dag_id,
                failed_task_instance.task_id,
                failed_task_instance.run_id,
            )
            if failed_task_instance.duration:
                fails_totals[dict_key] += failed_task_instance.duration

        for task_instance in task_instances:
            if task_instance.duration:
                date_time = wwwutils.epoch(task_instance.execution_date)
                x_points[task_instance.task_id].append(date_time)
                y_points[task_instance.task_id].append(float(task_instance.duration))
                fails_dict_key = (task_instance.dag_id, task_instance.task_id, task_instance.run_id)
                fails_total = fails_totals[fails_dict_key]
                cumulative_y[task_instance.task_id].append(float(task_instance.duration + fails_total))

        # determine the most relevant time unit for the set of task instance
        # durations for the DAG
        y_unit = infer_time_unit([d for t in y_points.values() for d in t])
        cum_y_unit = infer_time_unit([d for t in cumulative_y.values() for d in t])
        # update the y Axis on both charts to have the correct time units
        chart.create_y_axis('yAxis', format='.02f', custom_format=False, label=f'Duration ({y_unit})')
        chart.axislist['yAxis']['axisLabelDistance'] = '-15'
        cum_chart.create_y_axis('yAxis', format='.02f', custom_format=False, label=f'Duration ({cum_y_unit})')
        cum_chart.axislist['yAxis']['axisLabelDistance'] = '-15'

        for task_id in x_points:
            chart.add_serie(
                name=task_id,
                x=x_points[task_id],
                y=scale_time_units(y_points[task_id], y_unit),
            )
            cum_chart.add_serie(
                name=task_id,
                x=x_points[task_id],
                y=scale_time_units(cumulative_y[task_id], cum_y_unit),
            )

        dates = sorted({ti.execution_date for ti in task_instances})
        max_date = max(ti.execution_date for ti in task_instances) if dates else None

        session.commit()

        form = DateTimeWithNumRunsForm(
            data={
                'base_date': max_date or timezone.utcnow(),
                'num_runs': num_runs,
            }
        )
        chart.buildcontent()
        cum_chart.buildcontent()
        s_index = cum_chart.htmlcontent.rfind('});')
        cum_chart.htmlcontent = (
            cum_chart.htmlcontent[:s_index]
            + "$( document ).trigger('chartload')"
            + cum_chart.htmlcontent[s_index:]
        )

        return self.render_template(
            'airflow/duration_chart.html',
            dag=dag,
            root=root,
            form=form,
            chart=Markup(chart.htmlcontent),
            cum_chart=Markup(cum_chart.htmlcontent),
            dag_model=dag_model,
        )

    @expose('/tries')
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_TASK_INSTANCE),
        ]
    )
    @action_logging
    def legacy_tries(self):
        """Redirect from url param."""
        return redirect(url_for('Airflow.tries', **request.args))

    @expose('/dags/<string:dag_id>/tries')
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_TASK_INSTANCE),
        ]
    )
    @action_logging
    @provide_session
    def tries(self, dag_id, session=None):
        """Shows all tries."""
        dag = get_airflow_app().dag_bag.get_dag(dag_id, session=session)
        dag_model = DagModel.get_dagmodel(dag_id, session=session)
        if not dag:
            flash(f'DAG "{dag_id}" seems to be missing.', "error")
            return redirect(url_for('Airflow.index'))

        wwwutils.check_import_errors(dag.fileloc, session)
        wwwutils.check_dag_warnings(dag.dag_id, session)

        default_dag_run = conf.getint('webserver', 'default_dag_run_display_number')
        base_date = request.args.get('base_date')
        num_runs = request.args.get('num_runs', default=default_dag_run, type=int)

        if base_date:
            base_date = _safe_parse_datetime(base_date)
        else:
            base_date = dag.get_latest_execution_date() or timezone.utcnow()

        root = request.args.get('root')
        if root:
            dag = dag.partial_subset(task_ids_or_regex=root, include_upstream=True, include_downstream=False)

        chart_height = wwwutils.get_chart_height(dag)
        chart = nvd3.lineChart(
            name="lineChart",
            x_custom_format=True,
            x_axis_date=True,
            x_axis_format=LINECHART_X_AXIS_TICKFORMAT,
            height=chart_height,
            chart_attr=self.line_chart_attr,
        )

        tis = dag.get_task_instances_before(base_date, num_runs, session=session)
        for task in dag.tasks:
            y_points = []
            x_points = []
            for ti in tis:
                if ti.task_id != task.task_id:
                    continue
                dttm = wwwutils.epoch(ti.execution_date)
                x_points.append(dttm)
                # y value should reflect completed tries to have a 0 baseline.
                y_points.append(ti.prev_attempted_tries)
            if x_points:
                chart.add_serie(name=task.task_id, x=x_points, y=y_points)

        tries = sorted({ti.try_number for ti in tis})
        max_date = max(ti.execution_date for ti in tis) if tries else None
        chart.create_y_axis('yAxis', format='.02f', custom_format=False, label='Tries')
        chart.axislist['yAxis']['axisLabelDistance'] = '-15'

        session.commit()

        form = DateTimeWithNumRunsForm(
            data={
                'base_date': max_date or timezone.utcnow(),
                'num_runs': num_runs,
            }
        )

        chart.buildcontent()

        return self.render_template(
            'airflow/chart.html',
            dag=dag,
            root=root,
            form=form,
            chart=Markup(chart.htmlcontent),
            tab_title='Tries',
            dag_model=dag_model,
        )

    @expose('/landing_times')
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_TASK_INSTANCE),
        ]
    )
    @action_logging
    def legacy_landing_times(self):
        """Redirect from url param."""
        return redirect(url_for('Airflow.landing_times', **request.args))

    @expose('/dags/<string:dag_id>/landing-times')
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_TASK_INSTANCE),
        ]
    )
    @action_logging
    @provide_session
    def landing_times(self, dag_id, session=None):
        """Shows landing times."""
        dag = get_airflow_app().dag_bag.get_dag(dag_id, session=session)
        dag_model = DagModel.get_dagmodel(dag_id, session=session)
        if not dag:
            flash(f'DAG "{dag_id}" seems to be missing.', "error")
            return redirect(url_for('Airflow.index'))

        wwwutils.check_import_errors(dag.fileloc, session)
        wwwutils.check_dag_warnings(dag.dag_id, session)

        default_dag_run = conf.getint('webserver', 'default_dag_run_display_number')
        base_date = request.args.get('base_date')
        num_runs = request.args.get('num_runs', default=default_dag_run, type=int)

        if base_date:
            base_date = _safe_parse_datetime(base_date)
        else:
            base_date = dag.get_latest_execution_date() or timezone.utcnow()

        root = request.args.get('root')
        if root:
            dag = dag.partial_subset(task_ids_or_regex=root, include_upstream=True, include_downstream=False)

        tis = dag.get_task_instances_before(base_date, num_runs, session=session)

        chart_height = wwwutils.get_chart_height(dag)
        chart = nvd3.lineChart(
            name="lineChart",
            x_custom_format=True,
            x_axis_date=True,
            x_axis_format=LINECHART_X_AXIS_TICKFORMAT,
            height=chart_height,
            chart_attr=self.line_chart_attr,
        )
        y_points = {}
        x_points = {}
        for task in dag.tasks:
            task_id = task.task_id
            y_points[task_id] = []
            x_points[task_id] = []
            for ti in tis:
                if ti.task_id != task.task_id:
                    continue
                ts = dag.get_run_data_interval(ti.dag_run).end
                if ti.end_date:
                    dttm = wwwutils.epoch(ti.execution_date)
                    secs = (ti.end_date - ts).total_seconds()
                    x_points[task_id].append(dttm)
                    y_points[task_id].append(secs)

        # determine the most relevant time unit for the set of landing times
        # for the DAG
        y_unit = infer_time_unit([d for t in y_points.values() for d in t])
        # update the y Axis to have the correct time units
        chart.create_y_axis('yAxis', format='.02f', custom_format=False, label=f'Landing Time ({y_unit})')
        chart.axislist['yAxis']['axisLabelDistance'] = '-15'

        for task_id in x_points:
            chart.add_serie(
                name=task_id,
                x=x_points[task_id],
                y=scale_time_units(y_points[task_id], y_unit),
            )

        dates = sorted({ti.execution_date for ti in tis})
        max_date = max(ti.execution_date for ti in tis) if dates else None

        session.commit()

        form = DateTimeWithNumRunsForm(
            data={
                'base_date': max_date or timezone.utcnow(),
                'num_runs': num_runs,
            }
        )
        chart.buildcontent()

        return self.render_template(
            'airflow/chart.html',
            dag=dag,
            chart=Markup(chart.htmlcontent),
            height=str(chart_height + 100) + "px",
            root=root,
            form=form,
            tab_title='Landing times',
            dag_model=dag_model,
        )

    @expose('/paused', methods=['POST'])
    @auth.has_access(
        [
            (permissions.ACTION_CAN_EDIT, permissions.RESOURCE_DAG),
        ]
    )
    @action_logging
    def paused(self):
        """Toggle paused."""
        dag_id = request.args.get('dag_id')
        is_paused = request.args.get('is_paused') == 'false'
        models.DagModel.get_dagmodel(dag_id).set_is_paused(is_paused=is_paused)
        return "OK"

    @expose('/gantt')
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_TASK_INSTANCE),
        ]
    )
    @action_logging
    def legacy_gantt(self):
        """Redirect from url param."""
        return redirect(url_for('Airflow.gantt', **request.args))

    @expose('/dags/<string:dag_id>/gantt')
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_TASK_INSTANCE),
        ]
    )
    @action_logging
    @provide_session
    def gantt(self, dag_id, session=None):
        """Show GANTT chart."""
        dag = get_airflow_app().dag_bag.get_dag(dag_id, session=session)
        dag_model = DagModel.get_dagmodel(dag_id, session=session)
        if not dag:
            flash(f'DAG "{dag_id}" seems to be missing.', "error")
            return redirect(url_for('Airflow.index'))

        wwwutils.check_import_errors(dag.fileloc, session)
        wwwutils.check_dag_warnings(dag.dag_id, session)

        root = request.args.get('root')
        if root:
            dag = dag.partial_subset(task_ids_or_regex=root, include_upstream=True, include_downstream=False)

        dt_nr_dr_data = get_date_time_num_runs_dag_runs_form_data(request, session, dag)
        dttm = dt_nr_dr_data['dttm']
        dag_run = dag.get_dagrun(execution_date=dttm)
        dag_run_id = dag_run.run_id if dag_run else None

        form = DateTimeWithNumRunsWithDagRunsForm(data=dt_nr_dr_data)
        form.execution_date.choices = dt_nr_dr_data['dr_choices']

        tis = (
            session.query(TaskInstance)
            .filter(
                TaskInstance.dag_id == dag_id,
                TaskInstance.run_id == dag_run_id,
                TaskInstance.start_date.isnot(None),
                TaskInstance.state.isnot(None),
            )
            .order_by(TaskInstance.start_date)
        )

        ti_fails = session.query(TaskFail).filter_by(run_id=dag_run_id, dag_id=dag_id)
        if dag.partial:
            ti_fails = ti_fails.filter(TaskFail.task_id.in_([t.task_id for t in dag.tasks]))

        tasks = []
        for ti in tis:
            if not dag.has_task(ti.task_id):
                continue
            # prev_attempted_tries will reflect the currently running try_number
            # or the try_number of the last complete run
            # https://issues.apache.org/jira/browse/AIRFLOW-2143
            try_count = ti.prev_attempted_tries if ti.prev_attempted_tries != 0 else ti.try_number
            task_dict = alchemy_to_dict(ti)
            task_dict['end_date'] = task_dict['end_date'] or timezone.utcnow()
            task_dict['extraLinks'] = dag.get_task(ti.task_id).extra_links
            task_dict['try_number'] = try_count
            task_dict['execution_date'] = dttm.isoformat()
            task_dict['run_id'] = dag_run_id
            tasks.append(task_dict)

        tf_count = 0
        try_count = 1
        prev_task_id = ""
        for failed_task_instance in ti_fails:
            if not dag.has_task(failed_task_instance.task_id):
                continue
            if tf_count != 0 and failed_task_instance.task_id == prev_task_id:
                try_count += 1
            else:
                try_count = 1
            prev_task_id = failed_task_instance.task_id
            tf_count += 1
            task = dag.get_task(failed_task_instance.task_id)
            task_dict = alchemy_to_dict(failed_task_instance)
            end_date = task_dict['end_date'] or timezone.utcnow()
            task_dict['end_date'] = end_date
            task_dict['start_date'] = task_dict['start_date'] or end_date
            task_dict['state'] = State.FAILED
            task_dict['operator'] = task.task_type
            task_dict['try_number'] = try_count
            task_dict['extraLinks'] = task.extra_links
            task_dict['execution_date'] = dttm.isoformat()
            task_dict['run_id'] = dag_run_id
            tasks.append(task_dict)

        task_names = [ti.task_id for ti in tis]
        data = {
            'taskNames': task_names,
            'tasks': tasks,
            'height': len(task_names) * 25 + 25,
        }

        session.commit()

        return self.render_template(
            'airflow/gantt.html',
            dag=dag,
            dag_run_id=dag_run_id,
            execution_date=dttm.isoformat(),
            form=form,
            data=data,
            base_date='',
            root=root,
            dag_model=dag_model,
        )

    @expose('/extra_links')
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_TASK_INSTANCE),
        ]
    )
    @action_logging
    @provide_session
    def extra_links(self, session: "Session" = NEW_SESSION):
        """
        A restful endpoint that returns external links for a given Operator

        It queries the operator that sent the request for the links it wishes
        to provide for a given external link name.

        API: GET
        Args: dag_id: The id of the dag containing the task in question
              task_id: The id of the task in question
              execution_date: The date of execution of the task
              link_name: The name of the link reference to find the actual URL for

        Returns:
            200: {url: <url of link>, error: None} - returned when there was no problem
                finding the URL
            404: {url: None, error: <error message>} - returned when the operator does
                not return a URL
        """
        dag_id = request.args.get('dag_id')
        task_id = request.args.get('task_id')
        map_index = request.args.get('map_index', -1, type=int)
        execution_date = request.args.get('execution_date')
        dttm = _safe_parse_datetime(execution_date)
        dag = get_airflow_app().dag_bag.get_dag(dag_id)

        if not dag or task_id not in dag.task_ids:
            return {'url': None, 'error': f"can't find dag {dag} or task_id {task_id}"}, 404

        task: "AbstractOperator" = dag.get_task(task_id)
        link_name = request.args.get('link_name')
        if link_name is None:
            return {'url': None, 'error': 'Link name not passed'}, 400

        ti = (
            session.query(TaskInstance)
            .filter_by(dag_id=dag_id, task_id=task_id, execution_date=dttm, map_index=map_index)
            .options(joinedload(TaskInstance.dag_run))
            .first()
        )
        if not ti:
            return {'url': None, 'error': 'Task Instances not found'}, 404
        try:
            url = task.get_extra_links(ti, link_name)
        except ValueError as err:
            return {'url': None, 'error': str(err)}, 404
        if url:
            return {'error': None, 'url': url}
        else:
            return {'url': None, 'error': f'No URL found for {link_name}'}, 404

    @expose('/object/task_instances')
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_TASK_INSTANCE),
        ]
    )
    @action_logging
    def task_instances(self):
        """Shows task instances."""
        dag_id = request.args.get('dag_id')
        dag = get_airflow_app().dag_bag.get_dag(dag_id)

        dttm = request.args.get('execution_date')
        if dttm:
            dttm = _safe_parse_datetime(dttm)
        else:
            return {'error': f"Invalid execution_date {dttm}"}, 400

        with create_session() as session:
            task_instances = {
                ti.task_id: wwwutils.get_instance_with_map(ti, session)
                for ti in dag.get_task_instances(dttm, dttm)
            }

        return json.dumps(task_instances, cls=utils_json.AirflowJsonEncoder)

    @expose('/object/grid_data')
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_TASK_INSTANCE),
        ]
    )
    def grid_data(self):
        """Returns grid data"""
        dag_id = request.args.get('dag_id')
        dag = get_airflow_app().dag_bag.get_dag(dag_id)

        if not dag:
            return {'error': f"can't find dag {dag_id}"}, 404

        root = request.args.get('root')
        if root:
            dag = dag.partial_subset(task_ids_or_regex=root, include_downstream=False, include_upstream=True)

        num_runs = request.args.get('num_runs', type=int)
        if num_runs is None:
            num_runs = conf.getint('webserver', 'default_dag_run_display_number')

        try:
            base_date = timezone.parse(request.args["base_date"])
        except (KeyError, ValueError):
            base_date = dag.get_latest_execution_date() or timezone.utcnow()

        with create_session() as session:
            query = session.query(DagRun).filter(
                DagRun.dag_id == dag.dag_id, DagRun.execution_date <= base_date
            )

            run_type = request.args.get("run_type")
            if run_type:
                query = query.filter(DagRun.run_type == run_type)

            run_state = request.args.get("run_state")
            if run_state:
                query = query.filter(DagRun.state == run_state)

            dag_runs = query.order_by(DagRun.execution_date.desc()).limit(num_runs).all()
            dag_runs.reverse()
            encoded_runs = [wwwutils.encode_dag_run(dr) for dr in dag_runs]
            data = {
                'groups': dag_to_grid(dag, dag_runs, session),
                'dag_runs': encoded_runs,
            }
        # avoid spaces to reduce payload size
        return (
            htmlsafe_json_dumps(data, separators=(',', ':'), cls=utils_json.AirflowJsonEncoder),
            {'Content-Type': 'application/json; charset=utf-8'},
        )

    @expose('/object/next_run_datasets/<string:dag_id>')
    @auth.has_access([(permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG)])
    def next_run_datasets(self, dag_id):
        """Returns datasets necessary, and their status, for the next dag run"""
        dag = get_airflow_app().dag_bag.get_dag(dag_id)
        if not dag:
            return {'error': f"can't find dag {dag_id}"}, 404

        with create_session() as session:
            data = [
                dict(info)
                for info in session.query(
                    Dataset.id,
                    Dataset.uri,
                    DatasetDagRunQueue.created_at,
                )
                .join(DatasetDagRef, Dataset.id == DatasetDagRef.dataset_id)
                .join(
                    DatasetDagRunQueue,
                    and_(
                        DatasetDagRunQueue.dataset_id == DatasetDagRef.dataset_id,
                        DatasetDagRunQueue.target_dag_id == DatasetDagRef.dag_id,
                    ),
                    isouter=True,
                )
                .filter(DatasetDagRef.dag_id == dag_id)
                .order_by(Dataset.id)
                .all()
            ]
        return (
            htmlsafe_json_dumps(data, separators=(',', ':'), cls=utils_json.AirflowJsonEncoder),
            {'Content-Type': 'application/json; charset=utf-8'},
        )

    @expose('/robots.txt')
    @action_logging
    def robots(self):
        """
        Returns a robots.txt file for blocking certain search engine crawlers. This mitigates some
        of the risk associated with exposing Airflow to the public internet, however it does not
        address the real security risks associated with such a deployment.
        """
        return send_from_directory(get_airflow_app().static_folder, 'robots.txt')

    @expose('/audit_log')
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_AUDIT_LOG),
        ]
    )
    def legacy_audit_log(self):
        """Redirect from url param."""
        return redirect(url_for('Airflow.audit_log', **request.args))

    @expose('/dags/<string:dag_id>/audit_log')
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_AUDIT_LOG),
        ]
    )
    @provide_session
    def audit_log(self, dag_id: str, session=None):
        dag = get_airflow_app().dag_bag.get_dag(dag_id, session=session)
        dag_model = DagModel.get_dagmodel(dag_id, session=session)
        if not dag:
            flash(f'DAG "{dag_id}" seems to be missing from DagBag.', "error")
            return redirect(url_for('Airflow.index'))

        included_events_raw = conf.get('webserver', 'audit_view_included_events', fallback=None)
        excluded_events_raw = conf.get('webserver', 'audit_view_excluded_events', fallback=None)

        query = session.query(Log).filter(Log.dag_id == dag_id)
        if included_events_raw:
            included_events = {event.strip() for event in included_events_raw.split(',')}
            query = query.filter(Log.event.in_(included_events))
        elif excluded_events_raw:
            excluded_events = {event.strip() for event in excluded_events_raw.split(',')}
            query = query.filter(Log.event.notin_(excluded_events))

        dag_audit_logs = query.all()
        return self.render_template(
            'airflow/dag_audit_log.html',
            dag=dag,
            dag_model=dag_model,
            root=request.args.get('root'),
            dag_id=dag_id,
            dag_logs=dag_audit_logs,
            page_size=PAGE_SIZE,
        )


class ConfigurationView(AirflowBaseView):
    """View to show Airflow Configurations"""

    default_view = 'conf'

    class_permission_name = permissions.RESOURCE_CONFIG
    base_permissions = [
        permissions.ACTION_CAN_READ,
        permissions.ACTION_CAN_ACCESS_MENU,
    ]

    @expose('/configuration')
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_CONFIG),
        ]
    )
    def conf(self):
        """Shows configuration."""
        raw = request.args.get('raw') == "true"
        title = "Airflow Configuration"
        subtitle = AIRFLOW_CONFIG

        expose_config = conf.get('webserver', 'expose_config')

        # Don't show config when expose_config variable is False in airflow config
        # Don't show sensitive config values if expose_config variable is 'non-sensitive-only'
        # in airflow config
        if expose_config.lower() == 'non-sensitive-only':
            from airflow.configuration import SENSITIVE_CONFIG_VALUES

            updater = configupdater.ConfigUpdater()
            updater.read(AIRFLOW_CONFIG)
            for sect, key in SENSITIVE_CONFIG_VALUES:
                if updater.has_option(sect, key):
                    updater[sect][key].value = '< hidden >'
            config = str(updater)

            table = [
                (section, key, str(value), source)
                for section, parameters in conf.as_dict(True, False).items()
                for key, (value, source) in parameters.items()
            ]
        elif expose_config.lower() in ['true', 't', '1']:

            with open(AIRFLOW_CONFIG) as file:
                config = file.read()
            table = [
                (section, key, str(value), source)
                for section, parameters in conf.as_dict(True, True).items()
                for key, (value, source) in parameters.items()
            ]
        else:
            config = (
                "# Your Airflow administrator chose not to expose the "
                "configuration, most likely for security reasons."
            )
            table = None

        if raw:
            return Response(response=config, status=200, mimetype="application/text")
        else:
            code_html = Markup(
                highlight(
                    config,
                    lexers.IniLexer(),  # Lexer call
                    HtmlFormatter(noclasses=True),
                )
            )
            return self.render_template(
                'airflow/config.html',
                pre_subtitle=settings.HEADER + "  v" + airflow.__version__,
                code_html=code_html,
                title=title,
                subtitle=subtitle,
                table=table,
            )


class RedocView(AirflowBaseView):
    """Redoc Open API documentation"""

    default_view = 'redoc'

    @expose('/redoc')
    def redoc(self):
        """Redoc API documentation."""
        openapi_spec_url = url_for("/api/v1./api/v1_openapi_yaml")
        return self.render_template('airflow/redoc.html', openapi_spec_url=openapi_spec_url)


######################################################################################
#                                    ModelViews
######################################################################################


class DagFilter(BaseFilter):
    """Filter using DagIDs"""

    def apply(self, query, func):
        if get_airflow_app().appbuilder.sm.has_all_dags_access(g.user):
            return query
        filter_dag_ids = get_airflow_app().appbuilder.sm.get_accessible_dag_ids(g.user)
        return query.filter(self.model.dag_id.in_(filter_dag_ids))


class AirflowModelView(ModelView):
    """Airflow Mode View."""

    list_widget = AirflowModelListWidget
    page_size = PAGE_SIZE

    CustomSQLAInterface = wwwutils.CustomSQLAInterface


class AirflowPrivilegeVerifierModelView(AirflowModelView):
    """
    This ModelView prevents ability to pass primary keys of objects relating to DAGs you shouldn't be able to
    edit. This only holds for the add, update and delete operations.
    You will still need to use the `action_has_dag_edit_access()` for actions.
    """

    @staticmethod
    def validate_dag_edit_access(item: Union[DagRun, TaskInstance]):
        """Validates whether the user has 'can_edit' access for this specific DAG."""
        if not get_airflow_app().appbuilder.sm.can_edit_dag(item.dag_id):
            raise AirflowException(f"Access denied for dag_id {item.dag_id}")

    def pre_add(self, item: Union[DagRun, TaskInstance]):
        self.validate_dag_edit_access(item)

    def pre_update(self, item: Union[DagRun, TaskInstance]):
        self.validate_dag_edit_access(item)

    def pre_delete(self, item: Union[DagRun, TaskInstance]):
        self.validate_dag_edit_access(item)

    def post_add_redirect(self):  # Required to prevent redirect loop
        return redirect(self.get_default_url())

    def post_edit_redirect(self):  # Required to prevent redirect loop
        return redirect(self.get_default_url())

    def post_delete_redirect(self):  # Required to prevent redirect loop
        return redirect(self.get_default_url())


def action_has_dag_edit_access(action_func: Callable) -> Callable:
    """Decorator for actions which verifies you have DAG edit access on the given tis/drs."""

    @wraps(action_func)
    def check_dag_edit_acl_for_actions(
        self,
        items: Optional[Union[List[TaskInstance], List[DagRun], TaskInstance, DagRun]],
        *args,
        **kwargs,
    ) -> Callable:
        if items is None:
            dag_ids: Set[str] = set()
        elif isinstance(items, list):
            dag_ids = {item.dag_id for item in items if item is not None}
        elif isinstance(items, TaskInstance) or isinstance(items, DagRun):
            dag_ids = {items.dag_id}
        else:
            raise ValueError(
                "Was expecting the first argument of the action to be of type "
                "Optional[Union[List[TaskInstance], List[DagRun], TaskInstance, DagRun]]."
                f"Was of type: {type(items)}"
            )

        for dag_id in dag_ids:
            if not get_airflow_app().appbuilder.sm.can_edit_dag(dag_id):
                flash(f"Access denied for dag_id {dag_id}", "danger")
                logging.warning("User %s tried to modify %s without having access.", g.user.username, dag_id)
                return redirect(self.get_default_url())
        return action_func(self, items, *args, **kwargs)

    return check_dag_edit_acl_for_actions


class SlaMissModelView(AirflowModelView):
    """View to show SlaMiss table"""

    route_base = '/slamiss'

    datamodel = AirflowModelView.CustomSQLAInterface(SlaMiss)  # type: ignore

    class_permission_name = permissions.RESOURCE_SLA_MISS
    method_permission_name = {
        'list': 'read',
    }

    base_permissions = [
        permissions.ACTION_CAN_READ,
        permissions.ACTION_CAN_ACCESS_MENU,
    ]

    list_columns = ['dag_id', 'task_id', 'execution_date', 'email_sent', 'notification_sent', 'timestamp']

    label_columns = {
        'execution_date': 'Logical Date',
    }

    add_columns = ['dag_id', 'task_id', 'execution_date', 'email_sent', 'notification_sent', 'timestamp']
    edit_columns = ['dag_id', 'task_id', 'execution_date', 'email_sent', 'notification_sent', 'timestamp']
    search_columns = ['dag_id', 'task_id', 'email_sent', 'notification_sent', 'timestamp', 'execution_date']
    base_order = ('execution_date', 'desc')
    base_filters = [['dag_id', DagFilter, lambda: []]]

    formatters_columns = {
        'task_id': wwwutils.task_instance_link,
        'execution_date': wwwutils.datetime_f('execution_date'),
        'timestamp': wwwutils.datetime_f('timestamp'),
        'dag_id': wwwutils.dag_link,
        'map_index': wwwutils.format_map_index,
    }


class XComModelView(AirflowModelView):
    """View to show records from XCom table"""

    route_base = '/xcom'

    list_title = 'List XComs'

    datamodel = AirflowModelView.CustomSQLAInterface(XCom)

    class_permission_name = permissions.RESOURCE_XCOM
    method_permission_name = {
        'list': 'read',
        'delete': 'delete',
        'action_muldelete': 'delete',
    }
    base_permissions = [
        permissions.ACTION_CAN_CREATE,
        permissions.ACTION_CAN_READ,
        permissions.ACTION_CAN_DELETE,
        permissions.ACTION_CAN_ACCESS_MENU,
    ]

    search_columns = ['key', 'value', 'timestamp', 'dag_id', 'task_id', 'run_id', 'execution_date']
    list_columns = ['key', 'value', 'timestamp', 'dag_id', 'task_id', 'run_id', 'map_index', 'execution_date']
    base_order = ('dag_run_id', 'desc')

    base_filters = [['dag_id', DagFilter, lambda: []]]

    formatters_columns = {
        'task_id': wwwutils.task_instance_link,
        'timestamp': wwwutils.datetime_f('timestamp'),
        'dag_id': wwwutils.dag_link,
        'map_index': wwwutils.format_map_index,
        'execution_date': wwwutils.datetime_f('execution_date'),
    }

    @action('muldelete', 'Delete', "Are you sure you want to delete selected records?", single=False)
    def action_muldelete(self, items):
        """Multiple delete action."""
        self.datamodel.delete_all(items)
        self.update_redirect()
        return redirect(self.get_redirect())

    def pre_add(self, item):
        """Pre add hook."""
        item.execution_date = timezone.make_aware(item.execution_date)
        item.value = XCom.serialize_value(
            value=item.value,
            key=item.key,
            task_id=item.task_id,
            dag_id=item.dag_id,
            run_id=item.run_id,
            map_index=item.map_index,
        )

    def pre_update(self, item):
        """Pre update hook."""
        item.execution_date = timezone.make_aware(item.execution_date)
        item.value = XCom.serialize_value(
            value=item.value,
            key=item.key,
            task_id=item.task_id,
            dag_id=item.dag_id,
            run_id=item.run_id,
            map_index=item.map_index,
        )


def lazy_add_provider_discovered_options_to_connection_form():
    """Adds provider-discovered connection parameters as late as possible"""

    def _get_connection_types() -> List[Tuple[str, str]]:
        """Returns connection types available."""
        _connection_types = [
            ('fs', 'File (path)'),
            ('mesos_framework-id', 'Mesos Framework ID'),
            ('email', 'Email'),
            ('generic', 'Generic'),
        ]
        providers_manager = ProvidersManager()
        for connection_type, provider_info in providers_manager.hooks.items():
            if provider_info:
                _connection_types.append((connection_type, provider_info.hook_name))
        return _connection_types

    ConnectionForm.conn_type = SelectField(
        lazy_gettext('Connection Type'),
        choices=sorted(_get_connection_types(), key=itemgetter(1)),
        widget=Select2Widget(),
        validators=[InputRequired()],
        description="""
            Connection Type missing?
            Make sure you've installed the corresponding Airflow Provider Package.
        """,
    )
    for key, value in ProvidersManager().connection_form_widgets.items():
        setattr(ConnectionForm, key, value.field)
        ConnectionModelView.extra_field_name_mapping[key] = value.field_name
        ConnectionModelView.add_columns.append(key)
        ConnectionModelView.edit_columns.append(key)
        ConnectionModelView.extra_fields.append(key)


# Used to store a dictionary of field behaviours used to dynamically change available
# fields in ConnectionForm based on type of connection chosen
# See airflow.hooks.base_hook.DiscoverableHook for details on how to customize your Hooks.
#
# Additionally, a list of connection types that support testing via Airflow REST API is stored to dynamically
# enable/disable the Test Connection button.
#
# These field behaviours and testable connection types are rendered as scripts in the conn_create.html and
# conn_edit.html templates.
class ConnectionFormWidget(FormWidget):
    """Form widget used to display connection"""

    @cached_property
    def field_behaviours(self):
        return json.dumps(ProvidersManager().field_behaviours)

    @cached_property
    def testable_connection_types(self):
        return [
            connection_type
            for connection_type, hook_info in ProvidersManager().hooks.items()
            if hook_info and hook_info.connection_testable
        ]


class ConnectionModelView(AirflowModelView):
    """View to show records from Connections table"""

    route_base = '/connection'

    datamodel = AirflowModelView.CustomSQLAInterface(Connection)  # type: ignore

    class_permission_name = permissions.RESOURCE_CONNECTION
    method_permission_name = {
        'add': 'create',
        'list': 'read',
        'edit': 'edit',
        'delete': 'delete',
        'action_muldelete': 'delete',
        'action_mulduplicate': 'create',
    }

    base_permissions = [
        permissions.ACTION_CAN_CREATE,
        permissions.ACTION_CAN_READ,
        permissions.ACTION_CAN_EDIT,
        permissions.ACTION_CAN_DELETE,
        permissions.ACTION_CAN_ACCESS_MENU,
    ]

    list_columns = [
        'conn_id',
        'conn_type',
        'description',
        'host',
        'port',
        'is_encrypted',
        'is_extra_encrypted',
    ]
    add_columns = [
        'conn_id',
        'conn_type',
        'description',
        'host',
        'schema',
        'login',
        'password',
        'port',
        'extra',
    ]
    edit_columns = add_columns.copy()

    # Initialized later by lazy_add_provider_discovered_options_to_connection_form
    extra_fields: List[str] = []

    add_form = edit_form = ConnectionForm
    add_template = 'airflow/conn_create.html'
    edit_template = 'airflow/conn_edit.html'

    add_widget = ConnectionFormWidget
    edit_widget = ConnectionFormWidget

    base_order = ('conn_id', 'asc')

    extra_field_name_mapping: Dict[str, str] = {}

    @action('muldelete', 'Delete', 'Are you sure you want to delete selected records?', single=False)
    @auth.has_access(
        [
            (permissions.ACTION_CAN_EDIT, permissions.RESOURCE_DAG),
        ]
    )
    def action_muldelete(self, items):
        """Multiple delete."""
        self.datamodel.delete_all(items)
        self.update_redirect()
        return redirect(self.get_redirect())

    @action(
        'mulduplicate',
        'Duplicate',
        'Are you sure you want to duplicate the selected connections?',
        single=False,
    )
    @provide_session
    @auth.has_access(
        [
            (permissions.ACTION_CAN_CREATE, permissions.RESOURCE_CONNECTION),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_CONNECTION),
        ]
    )
    def action_mulduplicate(self, connections, session=None):
        """Duplicate Multiple connections"""
        for selected_conn in connections:
            new_conn_id = selected_conn.conn_id
            match = re.search(r"_copy(\d+)$", selected_conn.conn_id)

            base_conn_id = selected_conn.conn_id
            if match:
                base_conn_id = base_conn_id.split('_copy')[0]

            potential_connection_ids = [f"{base_conn_id}_copy{i}" for i in range(1, 11)]

            query = session.query(Connection.conn_id).filter(Connection.conn_id.in_(potential_connection_ids))

            found_conn_id_set = {conn_id for conn_id, in query}

            possible_conn_id_iter = (
                connection_id
                for connection_id in potential_connection_ids
                if connection_id not in found_conn_id_set
            )
            try:
                new_conn_id = next(possible_conn_id_iter)
            except StopIteration:
                flash(
                    f"Connection {new_conn_id} can't be added because it already exists, "
                    f"Please rename the existing connections",
                    "warning",
                )
            else:

                dup_conn = Connection(
                    new_conn_id,
                    selected_conn.conn_type,
                    selected_conn.description,
                    selected_conn.host,
                    selected_conn.login,
                    selected_conn.password,
                    selected_conn.schema,
                    selected_conn.port,
                    selected_conn.extra,
                )

                try:
                    session.add(dup_conn)
                    session.commit()
                    flash(f"Connection {new_conn_id} added successfully.", "success")
                except IntegrityError:
                    flash(
                        f"Connection {new_conn_id} can't be added. Integrity error, "
                        f"probably unique constraint.",
                        "warning",
                    )
                    session.rollback()

        self.update_redirect()
        return redirect(self.get_redirect())

    def process_form(self, form, is_created):
        """Process form data."""
        conn_id = form.data["conn_id"]
        conn_type = form.data["conn_type"]

        # The extra value is the combination of custom fields for this conn_type and the Extra field.
        # The extra form field with all extra values (including custom fields) is in the form being processed
        # so we start with those values, and override them with anything in the custom fields.
        extra = {}

        extra_json = form.data.get("extra")

        if extra_json:
            try:
                extra.update(json.loads(extra_json))
            except (JSONDecodeError, TypeError):
                flash(
                    Markup(
                        "<p>The <em>Extra</em> connection field contained an invalid value for Conn ID: "
                        f"<q>{conn_id}</q>.</p>"
                        "<p>If connection parameters need to be added to <em>Extra</em>, "
                        "please make sure they are in the form of a single, valid JSON object.</p><br>"
                        "The following <em>Extra</em> parameters were <b>not</b> added to the connection:<br>"
                        f"{extra_json}",
                    ),
                    category="error",
                )
        del extra_json

        for key in self.extra_fields:
            if key in form.data and key.startswith("extra__"):
                # Check to ensure the extra field corresponds to the connection type of the form submission
                # before adding to extra_field_name_mapping.
                conn_type_from_extra_field = key.split("__")[1]
                if conn_type_from_extra_field == conn_type:
                    value = form.data[key]
                    # Some extra fields have a default value of False so we need to explicitly check the
                    # value isn't an empty string.
                    if value != "":
                        field_name = self.extra_field_name_mapping[key]
                        extra[field_name] = value

        if extra.keys():
            form.extra.data = json.dumps(extra)

    def prefill_form(self, form, pk):
        """Prefill the form."""
        try:
            extra = form.data.get('extra')
            if extra is None:
                extra_dictionary = {}
            else:
                extra_dictionary = json.loads(extra)
        except JSONDecodeError:
            extra_dictionary = {}

        if not isinstance(extra_dictionary, dict):
            logging.warning('extra field for %s is not a dictionary', form.data.get('conn_id', '<unknown>'))
            return

        for field_key in self.extra_fields:
            field_name = self.extra_field_name_mapping[field_key]
            value = extra_dictionary.get(field_name, '')

            if not value:
                # check if connection `extra` json is using old prefixed field name style
                value = extra_dictionary.get(field_key, '')

            if value:
                field = getattr(form, field_key)
                field.data = value


class PluginView(AirflowBaseView):
    """View to show Airflow Plugins"""

    default_view = 'list'

    class_permission_name = permissions.RESOURCE_PLUGIN

    method_permission_name = {
        'list': 'read',
    }

    base_permissions = [
        permissions.ACTION_CAN_READ,
        permissions.ACTION_CAN_ACCESS_MENU,
    ]

    plugins_attributes_to_dump = [
        "hooks",
        "executors",
        "macros",
        "admin_views",
        "flask_blueprints",
        "menu_links",
        "appbuilder_views",
        "appbuilder_menu_items",
        "global_operator_extra_links",
        "operator_extra_links",
        "source",
    ]

    @expose('/plugin')
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_PLUGIN),
        ]
    )
    def list(self):
        """List loaded plugins."""
        plugins_manager.ensure_plugins_loaded()
        plugins_manager.integrate_executor_plugins()
        plugins_manager.initialize_extra_operators_links_plugins()
        plugins_manager.initialize_web_ui_plugins()

        plugins = []
        for plugin_no, plugin in enumerate(plugins_manager.plugins, 1):
            plugin_data = {
                'plugin_no': plugin_no,
                'plugin_name': plugin.name,
                'attrs': {},
            }
            for attr_name in self.plugins_attributes_to_dump:
                attr_value = getattr(plugin, attr_name)
                plugin_data['attrs'][attr_name] = attr_value

            plugins.append(plugin_data)

        title = "Airflow Plugins"
        doc_url = get_docs_url("plugins.html")
        return self.render_template(
            'airflow/plugin.html',
            plugins=plugins,
            title=title,
            doc_url=doc_url,
        )


class ProviderView(AirflowBaseView):
    """View to show Airflow Providers"""

    default_view = 'list'

    class_permission_name = permissions.RESOURCE_PROVIDER

    method_permission_name = {
        'list': 'read',
    }

    base_permissions = [
        permissions.ACTION_CAN_READ,
        permissions.ACTION_CAN_ACCESS_MENU,
    ]

    @expose('/provider')
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_PROVIDER),
        ]
    )
    def list(self):
        """List providers."""
        providers_manager = ProvidersManager()

        providers = []
        for pi in providers_manager.providers.values():
            provider_info = pi.data
            provider_data = {
                "package_name": provider_info["package-name"],
                "description": self._clean_description(provider_info["description"]),
                "version": pi.version,
                "documentation_url": get_doc_url_for_provider(provider_info["package-name"], pi.version),
            }
            providers.append(provider_data)

        title = "Providers"
        doc_url = get_docs_url("apache-airflow-providers/index.html")
        return self.render_template(
            'airflow/providers.html',
            providers=providers,
            title=title,
            doc_url=doc_url,
        )

    def _clean_description(self, description):
        def _build_link(match_obj):
            text = match_obj.group(1)
            url = match_obj.group(2)
            return markupsafe.Markup(f'<a href="{url}">{text}</a>')

        cd = markupsafe.escape(description)
        cd = re.sub(r"`(.*)[\s+]+&lt;(.*)&gt;`__", _build_link, cd)
        cd = re.sub(r"\n", r"<br>", cd)
        return markupsafe.Markup(cd)


class PoolModelView(AirflowModelView):
    """View to show records from Pool table"""

    route_base = '/pool'

    datamodel = AirflowModelView.CustomSQLAInterface(models.Pool)  # type: ignore

    class_permission_name = permissions.RESOURCE_POOL
    method_permission_name = {
        'add': 'create',
        'list': 'read',
        'edit': 'edit',
        'delete': 'delete',
        'action_muldelete': 'delete',
    }

    base_permissions = [
        permissions.ACTION_CAN_CREATE,
        permissions.ACTION_CAN_READ,
        permissions.ACTION_CAN_EDIT,
        permissions.ACTION_CAN_DELETE,
        permissions.ACTION_CAN_ACCESS_MENU,
    ]

    list_columns = ['pool', 'slots', 'running_slots', 'queued_slots']
    add_columns = ['pool', 'slots', 'description']
    edit_columns = ['pool', 'slots', 'description']

    base_order = ('pool', 'asc')

    @action('muldelete', 'Delete', 'Are you sure you want to delete selected records?', single=False)
    def action_muldelete(self, items):
        """Multiple delete."""
        if any(item.pool == models.Pool.DEFAULT_POOL_NAME for item in items):
            flash(f"{models.Pool.DEFAULT_POOL_NAME} cannot be deleted", 'error')
            self.update_redirect()
            return redirect(self.get_redirect())
        self.datamodel.delete_all(items)
        self.update_redirect()
        return redirect(self.get_redirect())

    @expose("/delete/<pk>", methods=["GET", "POST"])
    @has_access
    def delete(self, pk):
        """Single delete."""
        if models.Pool.is_default_pool(pk):
            flash(f"{models.Pool.DEFAULT_POOL_NAME} cannot be deleted", 'error')
            self.update_redirect()
            return redirect(self.get_redirect())

        return super().delete(pk)

    def pool_link(self):
        """Pool link rendering."""
        pool_id = self.get('pool')
        if pool_id is not None:
            url = url_for('TaskInstanceModelView.list', _flt_3_pool=pool_id)
            return Markup("<a href='{url}'>{pool_id}</a>").format(url=url, pool_id=pool_id)
        else:
            return Markup('<span class="label label-danger">Invalid</span>')

    def frunning_slots(self):
        """Running slots rendering."""
        pool_id = self.get('pool')
        running_slots = self.get('running_slots')
        if pool_id is not None and running_slots is not None:
            url = url_for('TaskInstanceModelView.list', _flt_3_pool=pool_id, _flt_3_state='running')
            return Markup("<a href='{url}'>{running_slots}</a>").format(url=url, running_slots=running_slots)
        else:
            return Markup('<span class="label label-danger">Invalid</span>')

    def fqueued_slots(self):
        """Queued slots rendering."""
        pool_id = self.get('pool')
        queued_slots = self.get('queued_slots')
        if pool_id is not None and queued_slots is not None:
            url = url_for('TaskInstanceModelView.list', _flt_3_pool=pool_id, _flt_3_state='queued')
            return Markup("<a href='{url}'>{queued_slots}</a>").format(url=url, queued_slots=queued_slots)
        else:
            return Markup('<span class="label label-danger">Invalid</span>')

    formatters_columns = {'pool': pool_link, 'running_slots': frunning_slots, 'queued_slots': fqueued_slots}

    validators_columns = {'pool': [validators.DataRequired()], 'slots': [validators.NumberRange(min=-1)]}


def _can_create_variable() -> bool:
    return get_airflow_app().appbuilder.sm.has_access(
        permissions.ACTION_CAN_CREATE, permissions.RESOURCE_VARIABLE
    )


class VariableModelView(AirflowModelView):
    """View to show records from Variable table"""

    route_base = '/variable'

    list_template = 'airflow/variable_list.html'
    edit_template = 'airflow/variable_edit.html'
    show_template = 'airflow/variable_show.html'

    show_widget = AirflowVariableShowWidget

    datamodel = AirflowModelView.CustomSQLAInterface(models.Variable)  # type: ignore

    class_permission_name = permissions.RESOURCE_VARIABLE
    method_permission_name = {
        'add': 'create',
        'list': 'read',
        'edit': 'edit',
        'show': 'read',
        'delete': 'delete',
        'action_muldelete': 'delete',
        'action_varexport': 'read',
    }
    base_permissions = [
        permissions.ACTION_CAN_CREATE,
        permissions.ACTION_CAN_READ,
        permissions.ACTION_CAN_EDIT,
        permissions.ACTION_CAN_DELETE,
        permissions.ACTION_CAN_ACCESS_MENU,
    ]

    list_columns = ['key', 'val', 'description', 'is_encrypted']
    add_columns = ['key', 'val', 'description']
    edit_columns = ['key', 'val', 'description']
    show_columns = ['key', 'val', 'description']
    search_columns = ['key', 'val']

    base_order = ('key', 'asc')

    def hidden_field_formatter(self):
        """Formats hidden fields"""
        key = self.get('key')
        val = self.get('val')
        if secrets_masker.should_hide_value_for_key(key):
            return Markup('*' * 8)
        if val:
            return val
        else:
            return Markup('<span class="label label-danger">Invalid</span>')

    formatters_columns = {
        'val': hidden_field_formatter,
    }

    validators_columns = {'key': [validators.DataRequired()]}

    def prefill_form(self, form, request_id):
        if secrets_masker.should_hide_value_for_key(form.key.data):
            form.val.data = '*' * 8

    def prefill_show(self, item):
        if secrets_masker.should_hide_value_for_key(item.key):
            item.val = '*' * 8

    def _show(self, pk):
        pages = get_page_args()
        page_sizes = get_page_size_args()
        orders = get_order_args()

        item = self.datamodel.get(pk, self._base_filters)
        if not item:
            abort(404)
        self.prefill_show(item)
        widgets = self._get_show_widget(pk, item)
        self.update_redirect()

        return self._get_related_views_widgets(
            item, orders=orders, pages=pages, page_sizes=page_sizes, widgets=widgets
        )

    extra_args = {"can_create_variable": _can_create_variable}

    @action('muldelete', 'Delete', 'Are you sure you want to delete selected records?', single=False)
    def action_muldelete(self, items):
        """Multiple delete."""
        self.datamodel.delete_all(items)
        self.update_redirect()
        return redirect(self.get_redirect())

    @action('varexport', 'Export', '', single=False)
    def action_varexport(self, items):
        """Export variables."""
        var_dict = {}
        decoder = json.JSONDecoder()
        for var in items:
            try:
                val = decoder.decode(var.val)
            except Exception:
                val = var.val
            var_dict[var.key] = val

        response = make_response(json.dumps(var_dict, sort_keys=True, indent=4))
        response.headers["Content-Disposition"] = "attachment; filename=variables.json"
        response.headers["Content-Type"] = "application/json; charset=utf-8"
        return response

    @expose('/varimport', methods=["POST"])
    @auth.has_access([(permissions.ACTION_CAN_CREATE, permissions.RESOURCE_VARIABLE)])
    @action_logging
    def varimport(self):
        """Import variables"""
        try:
            variable_dict = json.loads(request.files['file'].read())
        except Exception:
            self.update_redirect()
            flash("Missing file or syntax error.", 'error')
            return redirect(self.get_redirect())
        else:
            suc_count = fail_count = 0
            for k, v in variable_dict.items():
                try:
                    models.Variable.set(k, v, serialize_json=not isinstance(v, str))
                except Exception as e:
                    logging.info('Variable import failed: %s', repr(e))
                    fail_count += 1
                else:
                    suc_count += 1
            flash(f"{suc_count} variable(s) successfully updated.")
            if fail_count:
                flash(f"{fail_count} variable(s) failed to be updated.", 'error')
            self.update_redirect()
            return redirect(self.get_redirect())


class JobModelView(AirflowModelView):
    """View to show records from Job table"""

    route_base = '/job'

    datamodel = AirflowModelView.CustomSQLAInterface(BaseJob)  # type: ignore

    class_permission_name = permissions.RESOURCE_JOB
    method_permission_name = {
        'list': 'read',
    }
    base_permissions = [
        permissions.ACTION_CAN_READ,
        permissions.ACTION_CAN_ACCESS_MENU,
    ]

    list_columns = [
        'id',
        'dag_id',
        'state',
        'job_type',
        'start_date',
        'end_date',
        'latest_heartbeat',
        'executor_class',
        'hostname',
        'unixname',
    ]
    search_columns = [
        'id',
        'dag_id',
        'state',
        'job_type',
        'start_date',
        'end_date',
        'latest_heartbeat',
        'executor_class',
        'hostname',
        'unixname',
    ]

    base_order = ('start_date', 'desc')

    base_filters = [['dag_id', DagFilter, lambda: []]]

    formatters_columns = {
        'start_date': wwwutils.datetime_f('start_date'),
        'end_date': wwwutils.datetime_f('end_date'),
        'hostname': wwwutils.nobr_f('hostname'),
        'state': wwwutils.state_f,
        'latest_heartbeat': wwwutils.datetime_f('latest_heartbeat'),
    }


class DagRunModelView(AirflowPrivilegeVerifierModelView):
    """View to show records from DagRun table"""

    route_base = '/dagrun'

    datamodel = AirflowModelView.CustomSQLAInterface(models.DagRun)  # type: ignore

    class_permission_name = permissions.RESOURCE_DAG_RUN
    method_permission_name = {
        'list': 'read',
        'action_clear': 'edit',
        'action_muldelete': 'delete',
        'action_set_queued': 'edit',
        'action_set_running': 'edit',
        'action_set_failed': 'edit',
        'action_set_success': 'edit',
    }
    base_permissions = [
        permissions.ACTION_CAN_CREATE,
        permissions.ACTION_CAN_READ,
        permissions.ACTION_CAN_EDIT,
        permissions.ACTION_CAN_DELETE,
        permissions.ACTION_CAN_ACCESS_MENU,
    ]

    list_columns = [
        'state',
        'dag_id',
        'execution_date',
        'run_id',
        'run_type',
        'queued_at',
        'start_date',
        'end_date',
        'external_trigger',
        'conf',
        'duration',
    ]
    search_columns = [
        'state',
        'dag_id',
        'execution_date',
        'run_id',
        'run_type',
        'start_date',
        'end_date',
        'external_trigger',
    ]
    label_columns = {
        'execution_date': 'Logical Date',
    }
    edit_columns = ['state', 'dag_id', 'execution_date', 'start_date', 'end_date', 'run_id', 'conf']

    # duration is not a DB column, its derived
    order_columns = [
        'state',
        'dag_id',
        'execution_date',
        'run_id',
        'run_type',
        'queued_at',
        'start_date',
        'end_date',
        'external_trigger',
        'conf',
    ]

    base_order = ('execution_date', 'desc')

    base_filters = [['dag_id', DagFilter, lambda: []]]

    edit_form = DagRunEditForm

    def duration_f(self):
        """Duration calculation."""
        end_date = self.get('end_date')
        start_date = self.get('start_date')

        difference = '0s'
        if start_date and end_date:
            difference = td_format(end_date - start_date)

        return difference

    formatters_columns = {
        'execution_date': wwwutils.datetime_f('execution_date'),
        'state': wwwutils.state_f,
        'start_date': wwwutils.datetime_f('start_date'),
        'end_date': wwwutils.datetime_f('end_date'),
        'queued_at': wwwutils.datetime_f('queued_at'),
        'dag_id': wwwutils.dag_link,
        'run_id': wwwutils.dag_run_link,
        'conf': wwwutils.json_f('conf'),
        'duration': duration_f,
    }

    @action('muldelete', "Delete", "Are you sure you want to delete selected records?", single=False)
    @action_has_dag_edit_access
    @action_logging
    def action_muldelete(self, items: List[DagRun]):
        """Multiple delete."""
        self.datamodel.delete_all(items)
        self.update_redirect()
        return redirect(self.get_redirect())

    @action('set_queued', "Set state to 'queued'", '', single=False)
    @action_has_dag_edit_access
    @action_logging
    def action_set_queued(self, drs: List[DagRun]):
        """Set state to queued."""
        return self._set_dag_runs_to_active_state(drs, State.QUEUED)

    @action('set_running', "Set state to 'running'", '', single=False)
    @action_has_dag_edit_access
    @action_logging
    def action_set_running(self, drs: List[DagRun]):
        """Set state to running."""
        return self._set_dag_runs_to_active_state(drs, State.RUNNING)

    @provide_session
    def _set_dag_runs_to_active_state(self, drs: List[DagRun], state: str, session=None):
        """This routine only supports Running and Queued state."""
        try:
            count = 0
            for dr in session.query(DagRun).filter(DagRun.id.in_([dagrun.id for dagrun in drs])):
                count += 1
                if state == State.RUNNING:
                    dr.start_date = timezone.utcnow()
                dr.state = state
            session.commit()
            flash(f"{count} dag runs were set to {state}.")
        except Exception as ex:
            flash(str(ex), 'error')
            flash('Failed to set state', 'error')
        return redirect(self.get_default_url())

    @action(
        'set_failed',
        "Set state to 'failed'",
        "All running task instances would also be marked as failed, are you sure?",
        single=False,
    )
    @action_has_dag_edit_access
    @provide_session
    @action_logging
    def action_set_failed(self, drs: List[DagRun], session=None):
        """Set state to failed."""
        try:
            count = 0
            altered_tis = []
            for dr in session.query(DagRun).filter(DagRun.id.in_([dagrun.id for dagrun in drs])).all():
                count += 1
                altered_tis += set_dag_run_state_to_failed(
                    dag=get_airflow_app().dag_bag.get_dag(dr.dag_id),
                    run_id=dr.run_id,
                    commit=True,
                    session=session,
                )
            altered_ti_count = len(altered_tis)
            flash(f"{count} dag runs and {altered_ti_count} task instances were set to failed")
        except Exception:
            flash('Failed to set state', 'error')
        return redirect(self.get_default_url())

    @action(
        'set_success',
        "Set state to 'success'",
        "All task instances would also be marked as success, are you sure?",
        single=False,
    )
    @action_has_dag_edit_access
    @provide_session
    @action_logging
    def action_set_success(self, drs: List[DagRun], session=None):
        """Set state to success."""
        try:
            count = 0
            altered_tis = []
            for dr in session.query(DagRun).filter(DagRun.id.in_([dagrun.id for dagrun in drs])).all():
                count += 1
                altered_tis += set_dag_run_state_to_success(
                    dag=get_airflow_app().dag_bag.get_dag(dr.dag_id),
                    run_id=dr.run_id,
                    commit=True,
                    session=session,
                )
            altered_ti_count = len(altered_tis)
            flash(f"{count} dag runs and {altered_ti_count} task instances were set to success")
        except Exception:
            flash('Failed to set state', 'error')
        return redirect(self.get_default_url())

    @action('clear', "Clear the state", "All task instances would be cleared, are you sure?", single=False)
    @action_has_dag_edit_access
    @provide_session
    @action_logging
    def action_clear(self, drs: List[DagRun], session=None):
        """Clears the state."""
        try:
            count = 0
            cleared_ti_count = 0
            dag_to_tis: Dict[DAG, List[TaskInstance]] = {}
            for dr in session.query(DagRun).filter(DagRun.id.in_([dagrun.id for dagrun in drs])).all():
                count += 1
                dag = get_airflow_app().dag_bag.get_dag(dr.dag_id)
                tis_to_clear = dag_to_tis.setdefault(dag, [])
                tis_to_clear += dr.get_task_instances()

            for dag, tis in dag_to_tis.items():
                cleared_ti_count += len(tis)
                models.clear_task_instances(tis, session, dag=dag)

            flash(f"{count} dag runs and {cleared_ti_count} task instances were cleared")
        except Exception:
            flash('Failed to clear state', 'error')
        return redirect(self.get_default_url())


class LogModelView(AirflowModelView):
    """View to show records from Log table"""

    route_base = '/log'

    datamodel = AirflowModelView.CustomSQLAInterface(Log)  # type:ignore

    class_permission_name = permissions.RESOURCE_AUDIT_LOG
    method_permission_name = {
        'list': 'read',
    }
    base_permissions = [
        permissions.ACTION_CAN_READ,
        permissions.ACTION_CAN_ACCESS_MENU,
    ]

    list_columns = ['id', 'dttm', 'dag_id', 'task_id', 'event', 'execution_date', 'owner', 'extra']
    search_columns = ['dttm', 'dag_id', 'task_id', 'event', 'execution_date', 'owner', 'extra']

    label_columns = {
        'execution_date': 'Logical Date',
    }

    base_order = ('dttm', 'desc')

    base_filters = [['dag_id', DagFilter, lambda: []]]

    formatters_columns = {
        'dttm': wwwutils.datetime_f('dttm'),
        'execution_date': wwwutils.datetime_f('execution_date'),
        'dag_id': wwwutils.dag_link,
    }


class TaskRescheduleModelView(AirflowModelView):
    """View to show records from Task Reschedule table"""

    route_base = '/taskreschedule'

    datamodel = AirflowModelView.CustomSQLAInterface(models.TaskReschedule)  # type: ignore
    related_views = [DagRunModelView]

    class_permission_name = permissions.RESOURCE_TASK_RESCHEDULE
    method_permission_name = {
        'list': 'read',
    }

    base_permissions = [
        permissions.ACTION_CAN_READ,
        permissions.ACTION_CAN_ACCESS_MENU,
    ]

    list_columns = [
        'id',
        'dag_id',
        'run_id',
        'dag_run.execution_date',
        'task_id',
        'map_index',
        'try_number',
        'start_date',
        'end_date',
        'duration',
        'reschedule_date',
    ]

    label_columns = {
        'dag_run.execution_date': 'Logical Date',
    }

    search_columns = [
        'dag_id',
        'task_id',
        'run_id',
        'execution_date',
        'start_date',
        'end_date',
        'reschedule_date',
    ]

    base_order = ('id', 'desc')

    base_filters = [['dag_id', DagFilter, lambda: []]]

    def duration_f(self):
        """Duration calculation."""
        end_date = self.get('end_date')
        duration = self.get('duration')
        if end_date and duration:
            return td_format(timedelta(seconds=duration))
        return None

    formatters_columns = {
        'dag_id': wwwutils.dag_link,
        'task_id': wwwutils.task_instance_link,
        'start_date': wwwutils.datetime_f('start_date'),
        'end_date': wwwutils.datetime_f('end_date'),
        'dag_run.execution_date': wwwutils.datetime_f('dag_run.execution_date'),
        'reschedule_date': wwwutils.datetime_f('reschedule_date'),
        'duration': duration_f,
        'map_index': wwwutils.format_map_index,
    }


class TriggerModelView(AirflowModelView):
    """View to show records from Task Reschedule table"""

    route_base = '/triggerview'

    datamodel = AirflowModelView.CustomSQLAInterface(models.Trigger)  # type: ignore

    class_permission_name = permissions.RESOURCE_TRIGGER
    method_permission_name = {
        'list': 'read',
    }

    base_permissions = [
        permissions.ACTION_CAN_READ,
        permissions.ACTION_CAN_ACCESS_MENU,
    ]

    list_columns = [
        'id',
        'classpath',
        'created_date',
        'triggerer_id',
    ]

    search_columns = [
        'id',
        'classpath',
        'created_date',
        'triggerer_id',
    ]

    # add_exclude_columns = ["kwargs"]

    base_order = ('id', 'created_date')

    formatters_columns = {
        'created_date': wwwutils.datetime_f('created_date'),
    }


class TaskInstanceModelView(AirflowPrivilegeVerifierModelView):
    """View to show records from TaskInstance table"""

    route_base = '/taskinstance'

    datamodel = AirflowModelView.CustomSQLAInterface(models.TaskInstance)  # type: ignore

    class_permission_name = permissions.RESOURCE_TASK_INSTANCE
    method_permission_name = {
        'list': 'read',
        'action_muldelete': 'delete',
    }
    base_permissions = [
        permissions.ACTION_CAN_CREATE,
        permissions.ACTION_CAN_READ,
        permissions.ACTION_CAN_EDIT,
        permissions.ACTION_CAN_DELETE,
        permissions.ACTION_CAN_ACCESS_MENU,
    ]

    page_size = PAGE_SIZE

    list_columns = [
        'state',
        'dag_id',
        'task_id',
        'run_id',
        'map_index',
        'dag_run.execution_date',
        'operator',
        'start_date',
        'end_date',
        'duration',
        'job_id',
        'hostname',
        'unixname',
        'priority_weight',
        'queue',
        'queued_dttm',
        'try_number',
        'pool',
        'queued_by_job_id',
        'external_executor_id',
        'log_url',
    ]

    order_columns = [
        item for item in list_columns if item not in ['try_number', 'log_url', 'external_executor_id']
    ]

    label_columns = {
        'dag_run.execution_date': 'Logical Date',
    }

    search_columns = [
        'state',
        'dag_id',
        'task_id',
        'run_id',
        'map_index',
        'execution_date',
        'operator',
        'start_date',
        'end_date',
        'hostname',
        'priority_weight',
        'queue',
        'queued_dttm',
        'try_number',
        'pool',
        'queued_by_job_id',
    ]

    edit_columns = [
        'state',
        'start_date',
        'end_date',
    ]

    add_exclude_columns = ["next_method", "next_kwargs", "trigger_id"]

    edit_form = TaskInstanceEditForm

    base_order = ('job_id', 'asc')

    base_filters = [['dag_id', DagFilter, lambda: []]]

    def log_url_formatter(self):
        """Formats log URL."""
        log_url = self.get('log_url')
        return Markup(
            '<a href="{log_url}"><span class="material-icons" aria-hidden="true">reorder</span></a>'
        ).format(log_url=log_url)

    def duration_f(self):
        """Formats duration."""
        end_date = self.get('end_date')
        duration = self.get('duration')
        if end_date and duration:
            return td_format(timedelta(seconds=duration))
        return None

    formatters_columns = {
        'log_url': log_url_formatter,
        'task_id': wwwutils.task_instance_link,
        'run_id': wwwutils.dag_run_link,
        'map_index': wwwutils.format_map_index,
        'hostname': wwwutils.nobr_f('hostname'),
        'state': wwwutils.state_f,
        'dag_run.execution_date': wwwutils.datetime_f('dag_run.execution_date'),
        'start_date': wwwutils.datetime_f('start_date'),
        'end_date': wwwutils.datetime_f('end_date'),
        'queued_dttm': wwwutils.datetime_f('queued_dttm'),
        'dag_id': wwwutils.dag_link,
        'duration': duration_f,
    }

    @action(
        'clear',
        lazy_gettext('Clear'),
        lazy_gettext(
            'Are you sure you want to clear the state of the selected task'
            ' instance(s) and set their dagruns to the QUEUED state?'
        ),
        single=False,
    )
    @action_has_dag_edit_access
    @provide_session
    @action_logging
    def action_clear(self, task_instances, session=None):
        """Clears the action."""
        try:
            dag_to_tis = collections.defaultdict(list)

            for ti in task_instances:
                dag = get_airflow_app().dag_bag.get_dag(ti.dag_id)
                dag_to_tis[dag].append(ti)

            for dag, task_instances_list in dag_to_tis.items():
                models.clear_task_instances(task_instances_list, session, dag=dag)

            session.commit()
            flash(f"{len(task_instances)} task instances have been cleared")
        except Exception as e:
            flash(f'Failed to clear task instances: "{e}"', 'error')
        self.update_redirect()
        return redirect(self.get_redirect())

    @action('muldelete', 'Delete', "Are you sure you want to delete selected records?", single=False)
    @action_has_dag_edit_access
    @action_logging
    def action_muldelete(self, items):
        self.datamodel.delete_all(items)
        self.update_redirect()
        return redirect(self.get_redirect())

    @provide_session
    def set_task_instance_state(self, tis, target_state, session=None):
        """Set task instance state."""
        try:
            count = len(tis)
            for ti in tis:
                ti.set_state(target_state, session)
            session.commit()
            flash(f"{count} task instances were set to '{target_state}'")
        except Exception:
            flash('Failed to set state', 'error')

    @action('set_running', "Set state to 'running'", '', single=False)
    @action_has_dag_edit_access
    @action_logging
    def action_set_running(self, tis):
        """Set state to 'running'"""
        self.set_task_instance_state(tis, State.RUNNING)
        self.update_redirect()
        return redirect(self.get_redirect())

    @action('set_failed', "Set state to 'failed'", '', single=False)
    @action_has_dag_edit_access
    @action_logging
    def action_set_failed(self, tis):
        """Set state to 'failed'"""
        self.set_task_instance_state(tis, State.FAILED)
        self.update_redirect()
        return redirect(self.get_redirect())

    @action('set_success', "Set state to 'success'", '', single=False)
    @action_has_dag_edit_access
    @action_logging
    def action_set_success(self, tis):
        """Set state to 'success'"""
        self.set_task_instance_state(tis, State.SUCCESS)
        self.update_redirect()
        return redirect(self.get_redirect())

    @action('set_retry', "Set state to 'up_for_retry'", '', single=False)
    @action_has_dag_edit_access
    @action_logging
    def action_set_retry(self, tis):
        """Set state to 'up_for_retry'"""
        self.set_task_instance_state(tis, State.UP_FOR_RETRY)
        self.update_redirect()
        return redirect(self.get_redirect())

    @action('set_skipped', "Set state to 'skipped'", '', single=False)
    @action_has_dag_edit_access
    @action_logging
    def action_set_skipped(self, tis):
        """Set state to skipped."""
        self.set_task_instance_state(tis, TaskInstanceState.SKIPPED)
        self.update_redirect()
        return redirect(self.get_redirect())


class AutocompleteView(AirflowBaseView):
    """View to provide autocomplete results"""

    @auth.has_access([(permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG)])
    @provide_session
    @expose('/dagmodel/autocomplete')
    def autocomplete(self, session=None):
        """Autocomplete."""
        query = unquote(request.args.get('query', ''))

        if not query:
            return wwwutils.json_response([])

        # Provide suggestions of dag_ids and owners
        dag_ids_query = session.query(
            sqla.literal('dag').label('type'),
            DagModel.dag_id.label('name'),
        ).filter(~DagModel.is_subdag, DagModel.is_active, DagModel.dag_id.ilike('%' + query + '%'))

        owners_query = (
            session.query(
                sqla.literal('owner').label('type'),
                DagModel.owners.label('name'),
            )
            .distinct()
            .filter(~DagModel.is_subdag, DagModel.is_active, DagModel.owners.ilike('%' + query + '%'))
        )

        # Hide DAGs if not showing status: "all"
        status = flask_session.get(FILTER_STATUS_COOKIE)
        if status == 'active':
            dag_ids_query = dag_ids_query.filter(~DagModel.is_paused)
            owners_query = owners_query.filter(~DagModel.is_paused)
        elif status == 'paused':
            dag_ids_query = dag_ids_query.filter(DagModel.is_paused)
            owners_query = owners_query.filter(DagModel.is_paused)

        filter_dag_ids = get_airflow_app().appbuilder.sm.get_accessible_dag_ids(g.user)

        dag_ids_query = dag_ids_query.filter(DagModel.dag_id.in_(filter_dag_ids))
        owners_query = owners_query.filter(DagModel.dag_id.in_(filter_dag_ids))

        payload = [
            row._asdict() for row in dag_ids_query.union(owners_query).order_by('name').limit(10).all()
        ]
        return wwwutils.json_response(payload)


class DagDependenciesView(AirflowBaseView):
    """View to show dependencies between DAGs"""

    refresh_interval = timedelta(
        seconds=conf.getint(
            "webserver",
            "dag_dependencies_refresh_interval",
            fallback=conf.getint("scheduler", "dag_dir_list_interval"),
        )
    )
    last_refresh = timezone.utcnow() - refresh_interval
    nodes: List[Dict[str, Any]] = []
    edges: List[Dict[str, str]] = []

    @expose('/dag-dependencies')
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG_DEPENDENCIES),
        ]
    )
    @gzipped
    @action_logging
    def list(self):
        """Display DAG dependencies"""
        title = "DAG Dependencies"

        if not self.nodes or not self.edges:
            self._calculate_graph()
            self.last_refresh = timezone.utcnow()
        elif timezone.utcnow() > self.last_refresh + self.refresh_interval:
            max_last_updated = SerializedDagModel.get_max_last_updated_datetime()
            if max_last_updated is None or max_last_updated > self.last_refresh:
                self._calculate_graph()
            self.last_refresh = timezone.utcnow()

        return self.render_template(
            "airflow/dag_dependencies.html",
            title=title,
            nodes=self.nodes,
            edges=self.edges,
            last_refresh=self.last_refresh,
            arrange=conf.get("webserver", "dag_orientation"),
            width=request.args.get("width", "100%"),
            height=request.args.get("height", "800"),
        )

    def _calculate_graph(self):

        nodes_dict: Dict[str, Any] = {}
        edge_tuples: Set[Dict[str, str]] = set()

        for dag, dependencies in SerializedDagModel.get_dag_dependencies().items():
            dag_node_id = f"dag:{dag}"
            if dag_node_id not in nodes_dict:
                nodes_dict[dag_node_id] = self._node_dict(dag_node_id, dag, "dag")

            for dep in dependencies:
                if dep.node_id not in nodes_dict:
                    nodes_dict[dep.node_id] = self._node_dict(
                        dep.node_id, dep.dependency_id, dep.dependency_type
                    )
                edge_tuples.add((f"dag:{dep.source}", dep.node_id))
                edge_tuples.add((dep.node_id, f"dag:{dep.target}"))

        self.nodes = list(nodes_dict.values())
        self.edges = [{"u": u, "v": v} for u, v in edge_tuples]

    @staticmethod
    def _node_dict(node_id, label, node_class):
        return {
            "id": node_id,
            "value": {"label": label, "rx": 5, "ry": 5, "class": node_class},
        }


class ActionModelView(PermissionModelView):
    """Customize permission names for FAB's builtin PermissionModelView."""

    class_permission_name = permissions.RESOURCE_ACTION
    route_base = "/actions"
    method_permission_name = {
        'list': 'read',
    }
    base_permissions = [
        permissions.ACTION_CAN_READ,
    ]

    list_title = lazy_gettext("List Actions")
    show_title = lazy_gettext("Show Action")
    add_title = lazy_gettext("Add Action")
    edit_title = lazy_gettext("Edit Action")

    label_columns = {"name": lazy_gettext("Name")}


class PermissionPairModelView(PermissionViewModelView):
    """Customize permission names for FAB's builtin PermissionViewModelView."""

    class_permission_name = permissions.RESOURCE_PERMISSION
    route_base = "/permissions"
    method_permission_name = {
        'list': 'read',
    }
    base_permissions = [
        permissions.ACTION_CAN_READ,
    ]

    list_title = lazy_gettext("List Permissions")
    show_title = lazy_gettext("Show Permission")
    add_title = lazy_gettext("Add Permission")
    edit_title = lazy_gettext("Edit Permission")

    label_columns = {
        "action": lazy_gettext("Action"),
        "resource": lazy_gettext("Resource"),
    }
    list_columns = ["action", "resource"]


class CustomResetMyPasswordView(ResetMyPasswordView):
    """Customize permission names for FAB's builtin ResetMyPasswordView."""

    class_permission_name = permissions.RESOURCE_MY_PASSWORD
    method_permission_name = {
        'this_form_get': 'read',
        'this_form_post': 'edit',
    }
    base_permissions = [permissions.ACTION_CAN_EDIT, permissions.ACTION_CAN_READ]


class CustomResetPasswordView(ResetPasswordView):
    """Customize permission names for FAB's builtin ResetPasswordView."""

    class_permission_name = permissions.RESOURCE_PASSWORD
    method_permission_name = {
        'this_form_get': 'read',
        'this_form_post': 'edit',
    }

    base_permissions = [permissions.ACTION_CAN_EDIT, permissions.ACTION_CAN_READ]


class CustomRoleModelView(RoleModelView):
    """Customize permission names for FAB's builtin RoleModelView."""

    class_permission_name = permissions.RESOURCE_ROLE
    method_permission_name = {
        'delete': 'delete',
        'download': 'read',
        'show': 'read',
        'list': 'read',
        'edit': 'edit',
        'add': 'create',
        'copy_role': 'create',
    }
    base_permissions = [
        permissions.ACTION_CAN_CREATE,
        permissions.ACTION_CAN_READ,
        permissions.ACTION_CAN_EDIT,
        permissions.ACTION_CAN_DELETE,
    ]


class ResourceModelView(ViewMenuModelView):
    """Customize permission names for FAB's builtin ViewMenuModelView."""

    class_permission_name = permissions.RESOURCE_RESOURCE
    route_base = "/resources"
    method_permission_name = {
        'list': 'read',
    }
    base_permissions = [
        permissions.ACTION_CAN_READ,
    ]

    list_title = lazy_gettext("List Resources")
    show_title = lazy_gettext("Show Resource")
    add_title = lazy_gettext("Add Resource")
    edit_title = lazy_gettext("Edit Resource")

    label_columns = {"name": lazy_gettext("Name")}


class CustomUserInfoEditView(UserInfoEditView):
    """Customize permission names for FAB's builtin UserInfoEditView."""

    class_permission_name = permissions.RESOURCE_MY_PROFILE
    route_base = "/userinfoeditview"
    method_permission_name = {
        'this_form_get': 'edit',
        'this_form_post': 'edit',
    }
    base_permissions = [permissions.ACTION_CAN_EDIT, permissions.ACTION_CAN_READ]


class CustomUserStatsChartView(UserStatsChartView):
    """Customize permission names for FAB's builtin UserStatsChartView."""

    class_permission_name = permissions.RESOURCE_USER_STATS_CHART
    route_base = "/userstatschartview"
    method_permission_name = {
        'chart': 'read',
        'list': 'read',
    }
    base_permissions = [permissions.ACTION_CAN_READ]


class MultiResourceUserMixin:
    """Remaps UserModelView permissions to new resources and actions."""

    _class_permission_name = permissions.RESOURCE_USER

    class_permission_name_mapping = {
        'userinfoedit': permissions.RESOURCE_MY_PROFILE,
        'userinfo': permissions.RESOURCE_MY_PROFILE,
    }

    method_permission_name = {
        'userinfo': 'read',
        'download': 'read',
        'show': 'read',
        'list': 'read',
        'edit': 'edit',
        'userinfoedit': 'edit',
        'delete': 'delete',
    }

    base_permissions = [
        permissions.ACTION_CAN_READ,
        permissions.ACTION_CAN_EDIT,
        permissions.ACTION_CAN_DELETE,
    ]

    @property
    def class_permission_name(self):
        """Returns appropriate permission name depending on request method name."""
        if request:
            action_name = request.view_args.get("name")
            _, method_name = request.url_rule.endpoint.rsplit(".", 1)
            if method_name == 'action' and action_name:
                return self.class_permission_name_mapping.get(action_name, self._class_permission_name)
            if method_name:
                return self.class_permission_name_mapping.get(method_name, self._class_permission_name)
        return self._class_permission_name

    @class_permission_name.setter
    def class_permission_name(self, name):
        self._class_permission_name = name

    @expose("/show/<pk>", methods=["GET"])
    @has_access
    def show(self, pk):
        pk = self._deserialize_pk_if_composite(pk)
        widgets = self._show(pk)
        widgets['show'].template_args['actions'].pop('userinfoedit')
        return self.render_template(
            self.show_template,
            pk=pk,
            title=self.show_title,
            widgets=widgets,
            related_views=self._related_views,
        )


class CustomUserDBModelView(MultiResourceUserMixin, UserDBModelView):
    """Customize permission names for FAB's builtin UserDBModelView."""

    _class_permission_name = permissions.RESOURCE_USER

    class_permission_name_mapping = {
        'resetmypassword': permissions.RESOURCE_MY_PASSWORD,
        'resetpasswords': permissions.RESOURCE_PASSWORD,
        'userinfoedit': permissions.RESOURCE_MY_PROFILE,
        'userinfo': permissions.RESOURCE_MY_PROFILE,
    }

    method_permission_name = {
        'add': 'create',
        'download': 'read',
        'show': 'read',
        'list': 'read',
        'edit': 'edit',
        'delete': 'delete',
        'resetmypassword': 'read',
        'resetpasswords': 'read',
        'userinfo': 'read',
        'userinfoedit': 'read',
    }

    base_permissions = [
        permissions.ACTION_CAN_CREATE,
        permissions.ACTION_CAN_READ,
        permissions.ACTION_CAN_EDIT,
        permissions.ACTION_CAN_DELETE,
    ]


class CustomUserLDAPModelView(MultiResourceUserMixin, UserLDAPModelView):
    """Customize permission names for FAB's builtin UserLDAPModelView."""

    _class_permission_name = permissions.RESOURCE_USER

    class_permission_name_mapping = {
        'userinfoedit': permissions.RESOURCE_MY_PROFILE,
        'userinfo': permissions.RESOURCE_MY_PROFILE,
    }

    method_permission_name = {
        'add': 'create',
        'userinfo': 'read',
        'download': 'read',
        'show': 'read',
        'list': 'read',
        'edit': 'edit',
        'userinfoedit': 'edit',
        'delete': 'delete',
    }

    base_permissions = [
        permissions.ACTION_CAN_CREATE,
        permissions.ACTION_CAN_READ,
        permissions.ACTION_CAN_EDIT,
        permissions.ACTION_CAN_DELETE,
    ]


class CustomUserOAuthModelView(MultiResourceUserMixin, UserOAuthModelView):
    """Customize permission names for FAB's builtin UserOAuthModelView."""


class CustomUserOIDModelView(MultiResourceUserMixin, UserOIDModelView):
    """Customize permission names for FAB's builtin UserOIDModelView."""


class CustomUserRemoteUserModelView(MultiResourceUserMixin, UserRemoteUserModelView):
    """Customize permission names for FAB's builtin UserRemoteUserModelView."""

    _class_permission_name = permissions.RESOURCE_USER

    class_permission_name_mapping = {
        'userinfoedit': permissions.RESOURCE_MY_PROFILE,
        'userinfo': permissions.RESOURCE_MY_PROFILE,
    }

    method_permission_name = {
        'add': 'create',
        'userinfo': 'read',
        'download': 'read',
        'show': 'read',
        'list': 'read',
        'edit': 'edit',
        'userinfoedit': 'edit',
        'delete': 'delete',
    }

    base_permissions = [
        permissions.ACTION_CAN_CREATE,
        permissions.ACTION_CAN_READ,
        permissions.ACTION_CAN_EDIT,
        permissions.ACTION_CAN_DELETE,
    ]


def add_user_permissions_to_dag(sender, template, context, **extra):
    """
    Adds `.can_edit`, `.can_trigger`, and `.can_delete` properties
    to DAG based on current user's permissions.
    Located in `views.py` rather than the DAG model to keep
    permissions logic out of the Airflow core.
    """
    if 'dag' in context:
        dag = context['dag']
        can_create_dag_run = get_airflow_app().appbuilder.sm.has_access(
            permissions.ACTION_CAN_CREATE, permissions.RESOURCE_DAG_RUN
        )

        dag.can_edit = get_airflow_app().appbuilder.sm.can_edit_dag(dag.dag_id)
        dag.can_trigger = dag.can_edit and can_create_dag_run
        dag.can_delete = get_airflow_app().appbuilder.sm.can_delete_dag(dag.dag_id)
        context['dag'] = dag


# NOTE: Put this at the end of the file. Pylance is too clever and detects that
# before_render_template.connect() is declared as NoReturn, and marks everything
# after this line as unreachable code. It's technically correct based on the
# lint-time information, but that's not what actually happens at runtime.
before_render_template.connect(add_user_permissions_to_dag)