import asyncio

from sqlalchemy import select, event
import json

from orm.author import Author, AuthorFollower
from orm.topic import Topic, TopicFollower
from resolvers.stat import add_author_stat_columns, add_topic_stat_columns
from services.rediscache import redis


async def update_author(author):
    redis_key = f'user:{author.user}:author'

    await redis.execute(
        'SET',
        redis_key,
        json.dumps(
            {
                'id': author.id,
                'name': author.name,
                'slug': author.slug,
                'pic': author.pic,
                'bio': author.bio,
                'stat': author.stat,
            }
        ),
    )
    await redis.execute('EXPIRE', redis_key, 25 * 60 * 60)


@event.listens_for(Author, 'after_insert')
@event.listens_for(Author, 'after_update')
def after_author_update(mapper, connection, author: Author):
    asyncio.create_task(update_author(author))


@event.listens_for(TopicFollower, 'after_insert')
def after_topic_follower_insert(mapper, connection, target: TopicFollower):
    asyncio.create_task(
        handle_topic_follower_change(connection, target.topic, target.follower, True)
    )


@event.listens_for(TopicFollower, 'after_delete')
def after_topic_follower_delete(mapper, connection, target: TopicFollower):
    asyncio.create_task(
        handle_topic_follower_change(connection, target.topic, target.follower, False)
    )


@event.listens_for(AuthorFollower, 'after_insert')
def after_author_follower_insert(mapper, connection, target: AuthorFollower):
    asyncio.create_task(
        handle_author_follower_change(connection, target.author, target.follower, True)
    )


@event.listens_for(AuthorFollower, 'after_delete')
def after_author_follower_delete(mapper, connection, target: AuthorFollower):
    asyncio.create_task(
        handle_author_follower_change(connection, target.author, target.follower, False)
    )


async def update_follows_for_user(
    connection, user_id, entity_type, entity: dict, is_insert
):
    redis_key = f'user:{user_id}:follows'
    follows_str = await redis.get(redis_key)
    if follows_str:
        follows = json.loads(follows_str)
    else:
        follows = {
            'topics': [],
            'authors': [],
            'communities': [
                {'slug': 'discours', 'name': 'Дискурс', 'id': 1, 'desc': ''}
            ],
        }
    if is_insert:
        follows[f'{entity_type}s'].append(entity)
    else:
        # Remove the entity from follows
        follows[f'{entity_type}s'] = [
            e for e in follows[f'{entity_type}s'] if e['id'] != entity['id']
        ]
    await redis.execute('set', redis_key, json.dumps(follows))


async def handle_author_follower_change(connection, author_id, follower_id, is_insert):
    q = select(Author).filter(Author.id == author_id)
    q = add_author_stat_columns(q)
    async with connection.begin() as conn:
        [author, shouts_stat, followers_stat, followings_stat] = await conn.execute(
            q
        ).first()
        author.stat = {
            'shouts': shouts_stat,
            # 'viewed': await ViewedStorage.get_author(author.slug),
            'followers': followers_stat,
            'followings': followings_stat,
        }
        follower = await conn.execute(
            select(Author).filter(Author.id == follower_id)
        ).first()
        if follower and author:
            await update_follows_for_user(
                connection,
                follower.user,
                'author',
                {
                    'id': author.id,
                    'name': author.name,
                    'slug': author.slug,
                    'pic': author.pic,
                    'bio': author.bio,
                    'stat': author.stat,
                },
                is_insert,
            )


async def handle_topic_follower_change(connection, topic_id, follower_id, is_insert):
    q = select(Topic).filter(Topic.id == topic_id)
    q = add_topic_stat_columns(q)
    async with connection.begin() as conn:
        [topic, shouts_stat, authors_stat, followers_stat] = await conn.execute(
            q
        ).first()
        topic.stat = {
            'shouts': shouts_stat,
            'authors': authors_stat,
            'followers': followers_stat,
            # 'viewed': await ViewedStorage.get_topic(topic.slug),
        }
        follower = connection.execute(
            select(Author).filter(Author.id == follower_id)
        ).first()
        if follower and topic:
            await update_follows_for_user(
                connection,
                follower.user,
                'topic',
                {
                    'id': topic.id,
                    'title': topic.title,
                    'slug': topic.slug,
                    'body': topic.body,
                    'stat': topic.stat,
                },
                is_insert,
            )