import json
import time

from sqlalchemy import desc, select, or_, distinct, func
from sqlalchemy.orm import aliased

from orm.author import Author, AuthorFollower
from orm.shout import ShoutAuthor, ShoutTopic
from orm.topic import Topic
from resolvers.follower import query_follows
from resolvers.stat import (
    get_authors_with_stat,
    execute_with_ministat,
    author_follows_authors,
    author_follows_topics,
)
from services.auth import login_required
from services.db import local_session
from services.rediscache import redis
from services.schema import mutation, query
from services.logger import root_logger as logger


@mutation.field('update_author')
@login_required
def update_author(_, info, profile):
    user_id = info.context['user_id']
    with local_session() as session:
        author = session.query(Author).where(Author.user == user_id).first()
        Author.update(author, profile)
        session.add(author)
        session.commit()
    return {'error': None, 'author': author}


# TODO: caching query
@query.field('get_authors_all')
def get_authors_all(_, _info):
    with local_session() as session:
        authors = session.query(Author).all()
        return authors


@query.field('get_author')
def get_author(_, _info, slug='', author_id=None):
    q = None
    author = None
    try:
        if slug or author_id:
            if bool(slug):
                q = select(Author).where(Author.slug == slug)
            if author_id:
                q = select(Author).where(Author.id == author_id)

        [author] = get_authors_with_stat(q, ratings=True)
    except Exception as exc:
        logger.error(exc)
    return author


async def get_author_by_user_id(user_id: str, ratings=False):
    redis_key = f'user:{user_id}:author'
    author = None
    try:
        res = await redis.execute('GET', redis_key)
        if isinstance(res, str):
            author = json.loads(res)
            if author.get('id'):
                logger.debug(f'got cached author: {author}')
                return author

        logger.info(f'getting author id for {user_id}')
        q = select(Author).filter(Author.user == user_id)

        [author] = get_authors_with_stat(q, ratings)
    except Exception as exc:
        logger.error(exc)
    return author


@query.field('get_author_id')
async def get_author_id(_, _info, user: str):
    return await get_author_by_user_id(user, ratings=True)


@query.field('load_authors_by')
def load_authors_by(_, _info, by, limit, offset):
    q = select(Author)
    if by.get('slug'):
        q = q.filter(Author.slug.ilike(f"%{by['slug']}%"))
    elif by.get('name'):
        q = q.filter(Author.name.ilike(f"%{by['name']}%"))
    elif by.get('topic'):
        q = (
            q.join(ShoutAuthor)
            .join(ShoutTopic)
            .join(Topic)
            .where(Topic.slug == str(by['topic']))
        )

    if by.get('last_seen'):  # in unix time
        before = int(time.time()) - by['last_seen']
        q = q.filter(Author.last_seen > before)
    elif by.get('created_at'):  # in unix time
        before = int(time.time()) - by['created_at']
        q = q.filter(Author.created_at > before)

    order = by.get('order')
    if order == 'followers' or order == 'shouts':
        q = q.order_by(desc(f'{order}_stat'))

    q = q.limit(limit).offset(offset)

    authors = get_authors_with_stat(q)

    return authors


@query.field('get_author_follows')
def get_author_follows(_, _info, slug='', user=None, author_id=None):
    with local_session() as session:
        if user or slug:
            author_id_result = (
                session.query(Author.id)
                .filter(or_(Author.user == user, Author.slug == slug))
                .first()
            )
            author_id = author_id_result[0] if author_id_result else None
        if author_id:
            follows = query_follows(author_id)
            return follows
        else:
            raise ValueError('Author not found')


@query.field('get_author_follows_topics')
def get_author_follows_topics(_, _info, slug='', user=None, author_id=None):
    with local_session() as session:
        if user or slug:
            author_id_result = (
                session.query(Author.id)
                .filter(or_(Author.user == user, Author.slug == slug))
                .first()
            )
            author_id = author_id_result[0] if author_id_result else None
        if author_id:
            follows = author_follows_authors(author_id)
            return follows
        else:
            raise ValueError('Author not found')


@query.field('get_author_follows_authors')
def get_author_follows_authors(_, _info, slug='', user=None, author_id=None):
    with local_session() as session:
        if user or slug:
            author_id_result = (
                session.query(Author.id)
                .filter(or_(Author.user == user, Author.slug == slug))
                .first()
            )
            author_id = author_id_result[0] if author_id_result else None
        if author_id:
            follows = author_follows_topics(author_id)
            return follows
        else:
            raise ValueError('Author not found')


def create_author(user_id: str, slug: str, name: str = ''):
    with local_session() as session:
        new_author = Author(user=user_id, slug=slug, name=name)
        session.add(new_author)
        session.commit()
        logger.info(f'author created by webhook {new_author.dict()}')


@query.field('get_author_followers')
def get_author_followers(_, _info, slug: str):
    author_alias = aliased(Author)
    alias_author_followers = aliased(AuthorFollower)
    alias_author_authors = aliased(AuthorFollower)
    alias_author_follower_followers = aliased(AuthorFollower)
    alias_shout_author = aliased(ShoutAuthor)

    q = (
        select(author_alias)
        .join(alias_author_authors, alias_author_authors.follower == author_alias.id)
        .join(alias_author_followers, alias_author_followers.author == author_alias.id)
        .filter(author_alias.slug == slug)
        .add_columns(
            func.count(distinct(alias_shout_author.shout)).label('shouts_stat'),
            func.count(distinct(alias_author_authors.author)).label('authors_stat'),
            func.count(distinct(alias_author_follower_followers.follower)).label(
                'followers_stat'
            ),
        )
        .outerjoin(alias_shout_author, author_alias.id == alias_shout_author.author)
        .group_by(author_alias.id)
    )

    return execute_with_ministat(q)