# 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 os
import re
import subprocess
import time
import unittest
from datetime import datetime
from subprocess import check_call, check_output

import requests
import requests.exceptions
from requests.adapters import HTTPAdapter
from urllib3.util.retry import Retry

CLUSTER_FORWARDED_PORT = os.environ.get('CLUSTER_FORWARDED_PORT') or "8080"
KUBERNETES_HOST_PORT = (os.environ.get('CLUSTER_HOST') or "localhost") + ":" + CLUSTER_FORWARDED_PORT

print()
print(f"Cluster host/port used: ${KUBERNETES_HOST_PORT}")
print()


class TestKubernetesExecutor(unittest.TestCase):
    @staticmethod
    def _describe_resources(namespace: str):
        print("=" * 80)
        print(f"Describe resources for namespace {namespace}")
        print(f"Datetime: {datetime.utcnow()}")
        print("=" * 80)
        print("Describing pods")
        print("-" * 80)
        subprocess.call(["kubectl", "describe", "pod", "--namespace", namespace])
        print("=" * 80)
        print("Describing persistent volumes")
        print("-" * 80)
        subprocess.call(["kubectl", "describe", "pv", "--namespace", namespace])
        print("=" * 80)
        print("Describing persistent volume claims")
        print("-" * 80)
        subprocess.call(["kubectl", "describe", "pvc", "--namespace", namespace])
        print("=" * 80)

    @staticmethod
    def _num_pods_in_namespace(namespace):
        air_pod = check_output(['kubectl', 'get', 'pods', '-n', namespace]).decode()
        air_pod = air_pod.split('\n')
        names = [re.compile(r'\s+').split(x)[0] for x in air_pod if 'airflow' in x]
        return len(names)

    @staticmethod
    def _delete_airflow_pod(name=''):
        suffix = '-' + name if name else ''
        air_pod = check_output(['kubectl', 'get', 'pods']).decode()
        air_pod = air_pod.split('\n')
        names = [re.compile(r'\s+').split(x)[0] for x in air_pod if 'airflow' + suffix in x]
        if names:
            check_call(['kubectl', 'delete', 'pod', names[0]])

    def _get_session_with_retries(self):
        session = requests.Session()
        retries = Retry(total=3, backoff_factor=1)
        session.mount('http://', HTTPAdapter(max_retries=retries))
        session.mount('https://', HTTPAdapter(max_retries=retries))
        return session

    def _ensure_airflow_webserver_is_healthy(self):
        response = self.session.get(
            f"http://{KUBERNETES_HOST_PORT}/health",
            timeout=1,
        )

        assert response.status_code == 200

    def setUp(self):
        self.session = self._get_session_with_retries()
        self._ensure_airflow_webserver_is_healthy()

    def tearDown(self):
        self.session.close()

    def monitor_task(self, host, execution_date, dag_id, task_id, expected_final_state, timeout):
        tries = 0
        state = ''
        max_tries = max(int(timeout / 5), 1)
        # Wait some time for the operator to complete
        while tries < max_tries:
            time.sleep(5)
            # Trigger a new dagrun
            try:
                get_string = (
                    f'http://{host}/api/experimental/dags/{dag_id}/'
                    f'dag_runs/{execution_date}/tasks/{task_id}'
                )
                print(f"Calling [monitor_task]#1 {get_string}")
                result = self.session.get(get_string)
                if result.status_code == 404:
                    check_call(["echo", "api returned 404."])
                    tries += 1
                    continue
                assert result.status_code == 200, "Could not get the status"
                result_json = result.json()
                print(f"Received [monitor_task]#2: {result_json}")
                state = result_json['state']
                print(f"Attempt {tries}: Current state of operator is {state}")

                if state == expected_final_state:
                    break
                self._describe_resources(namespace="airflow")
                self._describe_resources(namespace="default")
                tries += 1
            except requests.exceptions.ConnectionError as e:
                check_call(["echo", f"api call failed. trying again. error {e}"])
        if state != expected_final_state:
            print(f"The expected state is wrong {state} != {expected_final_state} (expected)!")
        assert state == expected_final_state

    def ensure_dag_expected_state(self, host, execution_date, dag_id, expected_final_state, timeout):
        tries = 0
        state = ''
        max_tries = max(int(timeout / 5), 1)
        # Wait some time for the operator to complete
        while tries < max_tries:
            time.sleep(5)
            get_string = f'http://{host}/api/experimental/dags/{dag_id}/' f'dag_runs/{execution_date}'
            print(f"Calling {get_string}")
            # Trigger a new dagrun
            result = self.session.get(get_string)
            assert result.status_code == 200, "Could not get the status"
            result_json = result.json()
            print(f"Received: {result}")
            state = result_json['state']
            check_call(["echo", f"Attempt {tries}: Current state of dag is {state}"])
            print(f"Attempt {tries}: Current state of dag is {state}")

            if state == expected_final_state:
                break
            self._describe_resources("airflow")
            self._describe_resources("default")
            tries += 1
        assert state == expected_final_state

        # Maybe check if we can retrieve the logs, but then we need to extend the API

    def start_dag(self, dag_id, host):
        get_string = f'http://{host}/api/experimental/' f'dags/{dag_id}/paused/false'
        print(f"Calling [start_dag]#1 {get_string}")
        result = self.session.get(get_string)
        try:
            result_json = result.json()
        except ValueError:
            result_json = str(result)
        print(f"Received [start_dag]#1 {result_json}")
        assert result.status_code == 200, f"Could not enable DAG: {result_json}"
        post_string = f'http://{host}/api/experimental/' f'dags/{dag_id}/dag_runs'
        print(f"Calling [start_dag]#2 {post_string}")
        # Trigger a new dagrun
        result = self.session.post(post_string, json={})
        try:
            result_json = result.json()
        except ValueError:
            result_json = str(result)
        print(f"Received [start_dag]#2 {result_json}")
        assert result.status_code == 200, f"Could not trigger a DAG-run: {result_json}"

        time.sleep(1)

        get_string = f'http://{host}/api/experimental/latest_runs'
        print(f"Calling [start_dag]#3 {get_string}")
        result = self.session.get(get_string)
        assert result.status_code == 200, "Could not get the latest DAG-run:" " {result}".format(
            result=result.json()
        )
        result_json = result.json()
        print(f"Received: [start_dag]#3 {result_json}")
        return result_json

    def start_job_in_kubernetes(self, dag_id, host):
        result_json = self.start_dag(dag_id=dag_id, host=host)
        assert len(result_json['items']) > 0
        execution_date = None
        for dag_run in result_json['items']:
            if dag_run['dag_id'] == dag_id:
                execution_date = dag_run['execution_date']
                break
        assert execution_date is not None, f"No execution_date can be found for the dag with {dag_id}"
        return execution_date

    def test_integration_run_dag(self):
        host = KUBERNETES_HOST_PORT
        dag_id = 'example_kubernetes_executor_config'

        execution_date = self.start_job_in_kubernetes(dag_id, host)
        print(f"Found the job with execution date {execution_date}")

        # Wait some time for the operator to complete
        self.monitor_task(
            host=host,
            execution_date=execution_date,
            dag_id=dag_id,
            task_id='start_task',
            expected_final_state='success',
            timeout=300,
        )

        self.ensure_dag_expected_state(
            host=host,
            execution_date=execution_date,
            dag_id=dag_id,
            expected_final_state='success',
            timeout=300,
        )

    def test_integration_run_dag_with_scheduler_failure(self):
        host = KUBERNETES_HOST_PORT
        dag_id = 'example_kubernetes_executor_config'

        execution_date = self.start_job_in_kubernetes(dag_id, host)

        self._delete_airflow_pod("scheduler")

        time.sleep(10)  # give time for pod to restart

        # Wait some time for the operator to complete
        self.monitor_task(
            host=host,
            execution_date=execution_date,
            dag_id=dag_id,
            task_id='start_task',
            expected_final_state='success',
            timeout=300,
        )

        self.monitor_task(
            host=host,
            execution_date=execution_date,
            dag_id=dag_id,
            task_id='other_namespace_task',
            expected_final_state='success',
            timeout=300,
        )

        self.ensure_dag_expected_state(
            host=host,
            execution_date=execution_date,
            dag_id=dag_id,
            expected_final_state='success',
            timeout=300,
        )

        assert self._num_pods_in_namespace('test-namespace') == 0, "failed to delete pods in other namespace"