#       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.

from six.moves.urllib.parse import unquote, urlsplit, parse_qs
from datetime import datetime
import logging

import pymongo
from tg import expose, redirect, validate, request, flash, response
from tg.decorators import with_trailing_slash, without_trailing_slash, before_render, before_validate
from decorator import decorator

from tg import tmpl_context as c, app_globals as g
from webob import exc

from ming.base import Object
from ming.odm import session
from ming.utils import LazyProperty

from allura import model as M
from .base import BaseController
from allura.lib import utils
from allura.lib import helpers as h
from allura.lib.decorators import require_post, memorable_forget
from allura.lib.security import has_access, require_access

from allura.tasks import notification_tasks

from allura.lib.widgets import discuss as DW
from allura.lib.widgets import form_fields as ffw

from allura.model.auth import User
from allura.model.artifact import ArtifactReference
from .attachments import AttachmentsController, AttachmentController
from .feed import FeedArgs, FeedController
import six

log = logging.getLogger(__name__)


class pass_validator:
    def validate(self, v, s):
        return v


pass_validator = pass_validator()


class ModelConfig:
    Discussion = M.Discussion
    Thread = M.Thread
    Post = M.Post
    Attachment = M.DiscussionAttachment


class WidgetConfig:
    # Forms
    subscription_form = DW.SubscriptionForm()
    edit_post = DW.EditPost()
    moderate_thread = DW.ModerateThread()
    moderate_post = DW.ModeratePost()
    post_filter = DW.PostFilter()
    moderate_posts = DW.ModeratePosts()
    # Other widgets
    thread = DW.Thread()
    post = DW.Post()
    thread_header = DW.ThreadHeader()
    page_list = ffw.PageList()

# Controllers


class DiscussionController(BaseController, FeedController):
    M = ModelConfig
    W = WidgetConfig

    def __init__(self):
        if not hasattr(self, 'ThreadController'):
            self.ThreadController = ThreadController
        if not hasattr(self, 'PostController'):
            self.PostController = PostController
        if not hasattr(self, 'AttachmentController'):
            self.AttachmentController = DiscussionAttachmentController
        self.thread = ThreadsController(self)
        if not hasattr(self, 'moderate'):
            self.moderate = ModerationController(self)

    def error_handler(self, *args, **kwargs):
        redirect(six.ensure_text(request.referer or '/'))

    @h.vardec
    @expose()
    @validate(pass_validator, error_handler=error_handler)
    def subscribe(self, **kw):
        threads = kw.pop('threads', [])
        for t in threads:
            thread = self.M.Thread.query.get(_id=t['_id'])
            if t.get('subscription'):
                thread.subscribe()
            else:
                thread.unsubscribe()
            session(self.M.Thread)._get().skip_mod_date = True
            session(self.M.Thread)._get().skip_last_updated = True
        redirect(six.ensure_text(request.referer or '/'))

    def get_feed(self, project, app, user):
        """Return a :class:`allura.controllers.feed.FeedArgs` object describing
        the xml feed for this controller.

        Overrides :meth:`allura.controllers.feed.FeedController.get_feed`.

        """
        def query(since, until, page, limit, **kwargs):
            if not since and not until and not page:
                # simplest default case, so make the threads list shorter by grabbing only needed ones
                discussion_threads = self.discussion.thread_class().query.find(dict(
                    discussion_id=self.discussion._id,
                    num_replies={'$gt': 0},  # exclude empty threads (spam/deleted) like ForumController does
                )).sort([('last_post_date', pymongo.DESCENDING)]).limit(limit)
            else:
                discussion_threads = self.discussion.threads
            return dict(ref_id={'$in': [t.index_id() for t in discussion_threads]})
        return FeedArgs(
            query,
            'Recent posts to %s' % self.discussion.name,
            self.discussion.url())


class AppDiscussionController(DiscussionController):

    @LazyProperty
    def discussion(self):
        return self.M.Discussion.query.get(
            shortname=c.app.config.options.mount_point,
            app_config_id=c.app.config._id)


class ThreadsController(BaseController, metaclass=h.ProxiedAttrMeta):
    M = h.attrproxy('_discussion_controller', 'M')
    W = h.attrproxy('_discussion_controller', 'W')
    ThreadController = h.attrproxy(
        '_discussion_controller', 'ThreadController')
    PostController = h.attrproxy('_discussion_controller', 'PostController')
    AttachmentController = h.attrproxy(
        '_discussion_controller', 'AttachmentController')

    def __init__(self, discussion_controller):
        self._discussion_controller = discussion_controller

    @expose()
    def _lookup(self, id=None, *remainder):
        if id:
            id = unquote(id)
            return self.ThreadController(self._discussion_controller, id), remainder
        else:
            raise exc.HTTPNotFound()


class ThreadController(BaseController, FeedController, metaclass=h.ProxiedAttrMeta):
    M = h.attrproxy('_discussion_controller', 'M')
    W = h.attrproxy('_discussion_controller', 'W')
    ThreadController = h.attrproxy(
        '_discussion_controller', 'ThreadController')
    PostController = h.attrproxy('_discussion_controller', 'PostController')
    AttachmentController = h.attrproxy(
        '_discussion_controller', 'AttachmentController')

    def _check_security(self):
        require_access(self.thread, 'read')
        if self.thread.ref:
            require_access(self.thread.ref.artifact, 'read')

    def __init__(self, discussion_controller, thread_id):
        self._discussion_controller = discussion_controller
        self.discussion = discussion_controller.discussion
        self.thread = self.M.Thread.query.get(_id=thread_id)
        if not self.thread:
            url = '/p/{}/discussion/{}/'.format(c.project.shortname, c.forum.shortname)
            utils.permanent_redirect(url)

    @expose()
    def _lookup(self, id, *remainder):
        id = unquote(id)
        return self.PostController(self._discussion_controller, self.thread, id), remainder

    @with_trailing_slash
    @expose('jinja:allura:templates/discussion/thread.html')
    def index(self, limit=None, page=0, count=0, **kw):
        c.thread = self.W.thread
        c.thread_header = self.W.thread_header
        limit, page, start = g.handle_paging(limit, page)
        self.thread.num_views += 1
        # the update to num_views shouldn't affect it
        M.session.artifact_orm_session._get().skip_mod_date = True
        M.session.artifact_orm_session._get().skip_last_updated = True
        count = self.thread.query_posts(page=page, limit=int(limit)).count()

        return dict(discussion=self.thread.discussion,
                    thread=self.thread,
                    page=int(page),
                    count=int(count),
                    limit=int(limit),
                    show_moderate=kw.get('show_moderate'))

    def error_handler(self, *args, **kwargs):
        redirect(six.ensure_text(request.referer or '/'))

    @memorable_forget()
    @h.vardec
    @expose()
    @require_post()
    @validate(pass_validator, error_handler=error_handler)
    @utils.AntiSpam.validate('Spambot protection engaged')
    def post(self, **kw):
        handle_post_or_reply(thread=self.thread,
                             edit_widget=self.W.edit_post,
                             rate_limit=self.rate_limit,
                             kw=kw)

    @expose()
    @require_post()
    def tag(self, labels, **kw):
        require_access(self.thread, 'post')
        if self.thread.ref:
            require_access(self.thread.ref.artifact, 'post')
        self.thread.labels = labels.split(',')
        redirect(six.ensure_text(request.referer or '/'))

    @expose()
    def flag_as_spam(self, **kw):
        require_access(self.thread, 'moderate')
        self.thread.spam()
        flash('Thread flagged as spam.')
        redirect(self.discussion.url())

    def get_feed(self, project, app, user):
        """Return a :class:`allura.controllers.feed.FeedArgs` object describing
        the xml feed for this controller.

        Overrides :meth:`allura.controllers.feed.FeedController.get_feed`.

        """
        return FeedArgs(
            dict(ref_id=self.thread.index_id()),
            'Recent posts to %s' % (self.thread.subject or '(no subject)'),
            self.thread.url())


def handle_post_or_reply(thread, edit_widget, rate_limit, kw, parent_post_id=None):
    require_access(thread, 'post')
    rate_limit(M.Post, "Comment", redir=six.ensure_text(request.referer or '/'))
    if thread.ref:
        require_access(thread.ref.artifact, 'post')
    kw = edit_widget.to_python(kw, None)  # could raise Invalid, but doesn't seem like it ever does
    if not kw['text']:
        flash('Your post was not saved. You must provide content.',
              'error')
        redirect(six.ensure_text(request.referer or '/'))
    file_info = kw.get('file_info', None)
    p = thread.add_post(parent_id=parent_post_id, **kw)
    p.add_multiple_attachments(file_info)
    if thread.artifact:
        thread.artifact.mod_date = datetime.utcnow()
    flash('Message posted')
    notification_tasks.send_usermentions_notification.post(p.index_id(), kw['text'])
    redirect(six.ensure_text(request.referer or '/'))


class PostController(BaseController, metaclass=h.ProxiedAttrMeta):
    M = h.attrproxy('_discussion_controller', 'M')
    W = h.attrproxy('_discussion_controller', 'W')
    ThreadController = h.attrproxy(
        '_discussion_controller', 'ThreadController')
    PostController = h.attrproxy('_discussion_controller', 'PostController')
    AttachmentController = h.attrproxy(
        '_discussion_controller', 'AttachmentController')

    def _check_security(self):
        require_access(self.post, 'read')

    def __init__(self, discussion_controller, thread, slug):
        self._discussion_controller = discussion_controller
        self.thread = thread
        self._post_slug = slug
        self.attachment = DiscussionAttachmentsController(self.post)

    @LazyProperty
    def post(self):
        post = self.M.Post.query.get(
            slug=self._post_slug, thread_id=self.thread._id)
        if post:
            return post
        else:
            redirect('..')

    @h.vardec
    @expose('jinja:allura:templates/discussion/post.html')
    @validate(pass_validator)
    @utils.AntiSpam.validate('Spambot protection engaged')
    def index(self, version=None, **kw):
        c.post = self.W.post
        if request.method == 'POST':
            old_text = self.post.text
            require_access(self.post, 'moderate')
            post_fields = self.W.edit_post.to_python(kw, None)  # could raise Invalid, but doesn't seem like it does
            file_info = post_fields.pop('file_info', None)
            self.post.add_multiple_attachments(file_info)
            for k, v in post_fields.items():
                try:
                    setattr(self.post, k, v)
                except AttributeError:
                    continue
            self.post.edit_count = self.post.edit_count + 1
            self.post.last_edit_date = datetime.utcnow()
            self.post.last_edit_by_id = c.user._id
            self.thread.is_spam(self.post)  # run spam checker, nothing to do with result yet
            self.post.commit()
            notification_tasks.send_usermentions_notification.post(self.post.index_id(), kw['text'], old_text)
            g.director.create_activity(c.user, 'modified', self.post,
                                       target=self.post.thread.artifact or self.post.thread,
                                       related_nodes=[self.post.app_config.project],
                                       tags=['comment'])
            redirect(six.ensure_text(request.referer or '/'))
        elif request.method == 'GET':
            if self.post.deleted:
                raise exc.HTTPNotFound
            if version is not None:
                HC = self.post.__mongometa__.history_class
                ss = HC.query.find(
                    {'artifact_id': self.post._id, 'version': int(version)}).first()
                if not ss:
                    url = '/p/{}/discussion/{}/thread/{}/{}'.format(c.project.shortname, c.forum.shortname,
                                                                    self.thread._id, self._post_slug)
                    utils.permanent_redirect(url)

                class VersionedSnapshotTempObject(Object):
                    pass

                post = VersionedSnapshotTempObject(
                    ss.data,
                    acl=self.post.acl,
                    author=self.post.author,
                    url=self.post.url,
                    thread=self.post.thread,
                    reply_subject=self.post.reply_subject,
                    attachments=self.post.attachments,
                    related_artifacts=self.post.related_artifacts,
                    parent_security_context=lambda: None,
                    last_edit_by=lambda: self.post.last_edit_by(),
                    react_users=self.post.react_users
                )
            else:
                post = self.post
            return dict(discussion=self.post.discussion,
                        post=post)

    @without_trailing_slash
    @expose('json:')
    @require_post()
    def update_markdown(self, text=None, **kw):
        if has_access(self.post, 'moderate'):
            self.post.text = text
            self.post.edit_count = self.post.edit_count + 1
            self.post.last_edit_date = datetime.utcnow()
            self.post.last_edit_by_id = c.user._id
            self.post.commit()
            g.director.create_activity(c.user, 'modified', self.post,
                                       target=self.post.thread.artifact or self.post.thread,
                                       related_nodes=[self.post.app_config.project],
                                       tags=['comment'])
            return {
                'status': 'success'
            }
        else:
            return {
                'status': 'no_permission'
            }

    @expose()
    @without_trailing_slash
    def get_markdown(self):
        return self.post.text

    @expose('json:')
    @without_trailing_slash
    @require_post()
    def post_reaction(self, r, **kw):
        if c.user.is_anonymous():
            return {
                'error': 'no_permission'
            }
        status = 'ok'
        if r in utils.get_reaction_emoji_list():
            self.post.post_reaction(r, c.user)
        else:
            status = 'error'
        return dict(status=status, counts=self.post.react_counts)

    def error_handler(self, *args, **kwargs):
        redirect(six.ensure_text(request.referer or '/'))

    @memorable_forget()
    @h.vardec
    @expose()
    @require_post()
    @validate(pass_validator, error_handler=error_handler)
    @utils.AntiSpam.validate('Spambot protection engaged')
    @require_post(redir='.')
    def reply(self, **kw):
        handle_post_or_reply(thread=self.thread,
                             parent_post_id=self.post._id,
                             edit_widget=self.W.edit_post,
                             rate_limit=self.rate_limit,
                             kw=kw)

    @h.vardec
    @expose('json')
    @require_post()
    @validate(pass_validator, error_handler=error_handler)
    def moderate(self, **kw):
        require_access(self.post.thread, 'moderate')
        if kw.pop('delete', None):
            self.post.delete()
        elif kw.pop('spam', None):
            self.post.spam()
        elif kw.pop('undo', None):
            prev_status = kw.pop('prev_status', None)
            if self.post.status == 'spam' and prev_status == 'ok':
                g.spam_checker.submit_ham(self.post.text, artifact=self.post, user=self.post.author())
            self.post.undo(prev_status)
        elif kw.pop('approve', None):
            if self.post.status != 'ok':
                self.post.approve()
                g.spam_checker.submit_ham(self.post.text, artifact=self.post, user=self.post.author())
                self.post.thread.post_to_feed(self.post)
        return dict(result='success')

    @h.vardec
    @expose()
    @require_post()
    def attach(self, file_info=None):
        require_access(self.post, 'moderate')
        self.post.add_multiple_attachments(file_info)
        redirect(six.ensure_text(request.referer or '/'))

    @expose()
    def _lookup(self, id, *remainder):
        id = unquote(id)
        return self.PostController(
            self._discussion_controller,
            self.thread, self._post_slug + '/' + id), remainder


class DiscussionAttachmentController(AttachmentController):
    AttachmentClass = M.DiscussionAttachment
    edit_perm = 'moderate'


class DiscussionAttachmentsController(AttachmentsController):
    AttachmentControllerClass = DiscussionAttachmentController


class ModerationController(BaseController, metaclass=h.ProxiedAttrMeta):
    PostModel = M.Post
    M = h.attrproxy('_discussion_controller', 'M')
    W = h.attrproxy('_discussion_controller', 'W')
    ThreadController = h.attrproxy(
        '_discussion_controller', 'ThreadController')
    PostController = h.attrproxy('_discussion_controller', 'PostController')
    AttachmentController = h.attrproxy(
        '_discussion_controller', 'AttachmentController')

    def _check_security(self):
        require_access(self.discussion, 'moderate')

    def __init__(self, discussion_controller):
        self._discussion_controller = discussion_controller

    @LazyProperty
    def discussion(self):
        return self._discussion_controller.discussion

    @h.vardec
    @expose('jinja:allura:templates/discussion/moderate.html')
    @validate(pass_validator)
    def index(self, **kw):
        kw = WidgetConfig.post_filter.validate(kw, None)
        page = kw.pop('page', 0)
        limit = kw.pop('limit', 50)
        status = kw.pop('status', 'pending')
        username = kw.pop('username', None)
        flag = kw.pop('flag', None)
        c.post_filter = WidgetConfig.post_filter
        c.moderate_posts = WidgetConfig.moderate_posts
        c.page_list = WidgetConfig.page_list
        query = dict(
            discussion_id=self.discussion._id,
            deleted=False)
        if status != '-':
            query['status'] = status
        if flag:
            query['flags'] = {'$gte': int(flag)}
        if username:
            filtered_user = User.by_username(username)
            query['author_id'] = filtered_user._id if filtered_user else None
        q = self.PostModel.query.find(query).sort('timestamp', -1)
        count = q.count()
        limit, page, start = g.handle_paging(limit, page or 0, default=50)
        q = q.skip(start)
        q = q.limit(limit)
        pgnum = (page // limit) + 1
        pages = (count // limit) + 1
        return dict(discussion=self.discussion,
                    posts=q, page=page, limit=limit,
                    status=status, flag=flag, username=username,
                    pgnum=pgnum, pages=pages, count=count)

    @h.vardec
    @expose()
    @require_post()
    def save_moderation(self, post=[], delete=None, spam=None, approve=None, **kw):
        count = 0
        for p in post:
            posted = None
            if isinstance(p, dict):
                # regular form submit
                if 'checked' in p:
                    posted = self.PostModel.query.get(
                        _id=p['_id'],
                        # make sure nobody hacks the HTML form to moderate other
                        # posts
                        discussion_id=self.discussion._id,
                    )
            elif isinstance(p, self.PostModel):
                # called from save_moderation_bulk_user with models already
                posted = p
            else:
                raise TypeError('post list should be form fields, or Post models')

            if posted:
                if delete:
                    posted.delete()
                    # If we just deleted the last post in the
                    # thread, delete the thread.
                    if posted.thread and posted.thread.num_replies == 0:
                        count += 1
                        posted.thread.delete()
                elif spam and posted.status != 'spam':
                    count += 1
                    posted.spam()
                elif approve and posted.status != 'ok':
                    count += 1
                    posted.approve()
                    g.spam_checker.submit_ham(posted.text, artifact=posted, user=posted.author())
                    posted.thread.post_to_feed(posted)
        flash('{} {}'.format(h.text.plural(count, 'post', 'posts'),
                             'deleted' if delete else 'marked as spam' if spam else 'approved'))
        redirect(six.ensure_text(request.referer or '/'))

    @expose()
    @require_post()
    def save_moderation_bulk_user(self, username, **kw):
        # this is used by post.js as a quick way to deal with all a user's posts
        user = User.by_username(username)
        posts = self.PostModel.query.find({
            'author_id': user._id,
            'deleted': False,
            # this is what the main moderation forms does (e.g. single discussion within a forum app)
            # 'discussion_id': self.discussion._id
            # but instead want to do all discussions within this app
            'app_config_id': c.app.config._id
        })
        return self.save_moderation(posts, **kw)


class PostRestController(PostController):

    @expose('json:')
    def index(self, **kw):
        return dict(post=self.post.__json__())

    @h.vardec
    @expose()
    @require_post()
    @validate(pass_validator, error_handler=h.json_validation_error)
    def reply(self, **kw):
        require_access(self.thread, 'post')
        kw = self.W.edit_post.to_python(kw, None)  # could raise Invalid, but doesn't seem like it ever does
        post = self.thread.post(parent_id=self.post._id, **kw)
        self.thread.num_replies += 1
        redirect(post.slug.split('/')[-1] + '/')


class ThreadRestController(ThreadController):

    @expose('json:')
    def index(self, limit=25, page=None, **kw):
        limit, page = h.paging_sanitizer(limit, page)
        return dict(thread=self.thread.__json__(limit=limit, page=page))

    @h.vardec
    @expose()
    @require_post()
    @validate(pass_validator, error_handler=h.json_validation_error)
    def new(self, **kw):
        require_access(self.thread, 'post')
        kw = self.W.edit_post.to_python(kw, None)  # could raise Invalid, but doesn't seem like it ever does
        p = self.thread.add_post(**kw)
        redirect(p.slug + '/')


class AppDiscussionRestController(AppDiscussionController):
    ThreadController = ThreadRestController
    PostController = PostRestController