"""Backfill episode guids from megaphone.

Run this in dev with command
PYTHONPATH=. env/bin/python3.6 dev/backfill_episodes_guids.py -- -env dev -api_key=megaphone_token
"""

import argparse
import time

from podcast import config
from podcast.connectors import mysql
from podcast.models import episode as episode_model
from podcast.models.api_episode import ApiEpisode
from podcast.models.podcast import Podcast
from podcast.utils import api_utils


users = {
    'dev': '366',
    'qa': '1298',
    'prod': '88'
}


request_headers = None


def get_all_podcasts():
    """Return podcast id, network id, and podcast megaphone id of all the podcasts.

    Returns:
        list: containing the tuple of podcast id, network id, and megaphone id.
    """
    with mysql.pod_db_session(read_only=True) as session:
        podcasts = session.query(Podcast) \
            .with_entities(Podcast.id, Podcast.network_id, Podcast.megaphone_id) \
            .filter(Podcast.is_deleted.isnot(True)).all()

        return podcasts


def get_episodes_by_podcast_id(podcast_id):
    """Return all the episodes by podcast id.

    Args:
        podcast_id (int): the podcast identifier
    Returns:
        list: containing the dict of episodes.
    """
    with mysql.pod_db_session(read_only=True) as session:
        episodes = session.query(episode_model.Episode).filter(
            episode_model.Episode.podcast_id == podcast_id,
            episode_model.Episode.is_deleted.isnot(True)
        ).all()

        return [episode.to_dict() for episode in episodes]


def backfill_episodes_guids():
    """Backfill all the non-matching episode guids from megaphone.

    Get all podcasts from db
    Iterate each db podcast
        Get all episodes for each podcast from db and megaphone
            Iterate each db episode
                Check if megaphone episode matches with db episode
                    If match, check if megaphone guid exist and matches db episode uuid
                        Update episode uuid with megaphone guid for the episode in db
        Log any error/exception, one of the known exception is podcast not found in megaphone which gives 403 error
    """
    mp_api_call_count = 0
    all_orch_podcasts = get_all_podcasts()
    for orch_podcast in all_orch_podcasts:
        podcast_id, network_id, podcast_mp_id = orch_podcast
        try:
            if mp_api_call_count > 10:  # avoid status 429 too many calls to megaphone api
                mp_api_call_count = 0
                time.sleep(10)

            orch_episodes = get_episodes_by_podcast_id(podcast_id)
            mp_api_episode = ApiEpisode(network_id)
            mp_api_call_count += 1
            mp_episodes = mp_api_episode.get_all(podcast_mp_id, page=1, per_page=500)['items']
            for orch_episode in orch_episodes:
                mp_episode = next((
                    mp_episode for mp_episode in mp_episodes if mp_episode['id'] == orch_episode['megaphone_id']
                ), None)

                if mp_episode:
                    if mp_episode['guid'] and mp_episode['guid'] != orch_episode['uuid']:
                        updated_episode = episode_model.update_episode(orch_episode['id'], {'uuid': mp_episode['guid']})

                        success_message = 'Updated guid of episode: {} from: {} to: {}\n'.format(
                            orch_episode['id'], orch_episode['uuid'], updated_episode['uuid'])
                        print(success_message)
        except Exception as error:
            error_message = 'Failed for podcast: {} with error: {}\n'.format(podcast_id, error)
            print(error_message)


def main():
    """Extract shell arguments and start backfilling episode guids."""
    global request_headers
    argparser = argparse.ArgumentParser(prog='Backfill episodes guids')
    argparser.add_argument('-api_key', required=True, help='Megaphone API Key')
    argparser.add_argument('-env', required=True, help='env', default='qa')

    args = argparser.parse_args()
    config.MEGAPHONE_API_TOKEN = args.api_key
    env = args.env

    def get_user_id():
        """Mock get user id return value."""
        return users[env]

    api_utils.get_user_id = get_user_id

    request_headers = {
        'Grass-Account-Type': 'vendor',
        'Grass-Account-Id': '1',
        'Correlation-Id': '12',
        'Orchard-Identity-UUID': 'podcast-admin',
        'Content-Type': 'application/json'
    }

    backfill_episodes_guids()


if __name__ == '__main__':
    main()