import asyncio
import sys
from typing import Any, Optional

from sqlalchemy import and_, distinct, func, join, select
from sqlalchemy.orm import aliased
from sqlalchemy.sql.expression import Select

from auth.orm import Author, AuthorFollower
from cache.cache import cache_author
from orm.community import Community, CommunityFollower
from orm.reaction import Reaction, ReactionKind
from orm.shout import Shout, ShoutAuthor, ShoutTopic
from orm.topic import Topic, TopicFollower
from services.db import local_session
from utils.logger import root_logger as logger

# Type alias for queries
QueryType = Select


def add_topic_stat_columns(q: QueryType) -> QueryType:
    """
    Добавляет статистические колонки к запросу тем.

    :param q: SQL-запрос для получения тем.
    :return: Запрос с добавленными колонками статистики.
    """
    # Создаем алиасы для предотвращения конфликтов имен
    aliased_shout = aliased(ShoutTopic)

    # Создаем новый объект запроса для тем
    new_q = select(Topic)

    # Применяем необходимые фильтры и добавляем колонки статистики
    new_q = (
        new_q.join(
            aliased_shout,
            aliased_shout.topic == Topic.id,
        )
        .join(
            Shout,
            and_(
                aliased_shout.shout == Shout.id,
                Shout.deleted_at.is_(None),
            ),
        )
        .add_columns(
            func.count(distinct(aliased_shout.shout)).label("shouts_stat")
        )  # Подсчет уникальных публикаций для темы
    )

    aliased_follower = aliased(TopicFollower)

    # Добавляем количество подписчиков темы
    new_q = new_q.outerjoin(aliased_follower, aliased_follower.topic == Topic.id).add_columns(
        func.count(distinct(aliased_follower.follower)).label("followers_stat")
    )

    # Группировка по идентификатору темы
    return new_q.group_by(Topic.id)


def add_author_stat_columns(q: QueryType) -> QueryType:
    """
    Добавляет статистические колонки к запросу авторов.

    :param q: SQL-запрос для получения авторов.
    :return: Запрос с добавленными колонками статистики.
    """
    # Подзапрос для подсчета публикаций
    shouts_subq = (
        select(func.count(distinct(Shout.id)))
        .select_from(ShoutAuthor)
        .join(Shout, and_(Shout.id == ShoutAuthor.shout, Shout.deleted_at.is_(None)))
        .where(ShoutAuthor.author == Author.id)
        .scalar_subquery()
    )

    # Подзапрос для подсчета подписчиков
    followers_subq = (
        select(func.count(distinct(AuthorFollower.follower)))
        .where(AuthorFollower.author == Author.id)
        .scalar_subquery()
    )

    # Основной запрос
    return (
        q.select_from(Author)
        .add_columns(shouts_subq.label("shouts_stat"), followers_subq.label("followers_stat"))
        .group_by(Author.id)
    )


def get_topic_shouts_stat(topic_id: int) -> int:
    """
    Получает количество опубликованных постов для темы
    """
    q = (
        select(func.count(distinct(ShoutTopic.shout)))
        .select_from(join(ShoutTopic, Shout, ShoutTopic.shout == Shout.id))
        .filter(
            and_(
                ShoutTopic.topic == topic_id,
                Shout.published_at.is_not(None),
                Shout.deleted_at.is_(None),
            )
        )
    )

    with local_session() as session:
        result = session.execute(q).scalar()
        return int(result) if result else 0


def get_topic_authors_stat(topic_id: int) -> int:
    """
    Получает количество уникальных авторов для указанной темы.

    :param topic_id: Идентификатор темы.
    :return: Количество уникальных авторов, связанных с темой.
    """
    count_query = (
        select(func.count(distinct(ShoutAuthor.author)))
        .select_from(join(ShoutTopic, Shout, ShoutTopic.shout == Shout.id))
        .join(ShoutAuthor, ShoutAuthor.shout == Shout.id)
        .filter(
            and_(
                ShoutTopic.topic == topic_id,
                Shout.published_at.is_not(None),
                Shout.deleted_at.is_(None),
            )
        )
    )

    # Выполнение запроса и получение результата
    with local_session() as session:
        result = session.execute(count_query).scalar()
        return int(result) if result else 0


def get_topic_followers_stat(topic_id: int) -> int:
    """
    Получает количество подписчиков для указанной темы.

    :param topic_id: Идентификатор темы.
    :return: Количество уникальных подписчиков темы.
    """
    aliased_followers = aliased(TopicFollower)
    q = select(func.count(distinct(aliased_followers.follower))).filter(aliased_followers.topic == topic_id)
    with local_session() as session:
        result = session.execute(q).scalar()
        return int(result) if result else 0


def get_topic_comments_stat(topic_id: int) -> int:
    """
    Получает количество комментариев для всех публикаций в указанной теме.

    :param topic_id: Идентификатор темы.
    :return: Общее количество комментариев к публикациям темы.
    """
    # Подзапрос для получения количества комментариев для каждой публикации
    sub_comments = (
        select(
            Shout.id.label("shout_id"),
            func.coalesce(func.count(Reaction.id), 0).label("comments_count"),
        )
        .join(ShoutTopic, ShoutTopic.shout == Shout.id)
        .join(Topic, ShoutTopic.topic == Topic.id)
        .outerjoin(
            Reaction,
            and_(
                Reaction.shout == Shout.id,
                Reaction.kind == ReactionKind.COMMENT.value,
                Reaction.deleted_at.is_(None),
            ),
        )
        .group_by(Shout.id)
        .subquery()
    )
    # Запрос для суммирования количества комментариев по теме
    q = select(func.coalesce(func.sum(sub_comments.c.comments_count), 0)).filter(ShoutTopic.topic == topic_id)
    q = q.outerjoin(sub_comments, ShoutTopic.shout == sub_comments.c.shout_id)
    with local_session() as session:
        result = session.execute(q).scalar()
        return int(result) if result else 0


def get_author_shouts_stat(author_id: int) -> int:
    """
    Получает количество опубликованных постов для автора
    """
    aliased_shout_author = aliased(ShoutAuthor)
    aliased_shout = aliased(Shout)

    q = (
        select(func.count(distinct(aliased_shout.id)))
        .select_from(aliased_shout)
        .join(aliased_shout_author, aliased_shout.id == aliased_shout_author.shout)
        .filter(
            and_(
                aliased_shout_author.author == author_id,
                aliased_shout.published_at.is_not(None),
                aliased_shout.deleted_at.is_(None),
            )
        )
    )

    with local_session() as session:
        result = session.execute(q).scalar()
        return int(result) if result else 0


def get_author_authors_stat(author_id: int) -> int:
    """
    Получает количество уникальных авторов, с которыми взаимодействовал указанный автор
    """
    q = (
        select(func.count(distinct(ShoutAuthor.author)))
        .select_from(ShoutAuthor)
        .join(Shout, ShoutAuthor.shout == Shout.id)
        .join(Reaction, Reaction.shout == Shout.id)
        .filter(
            and_(
                Reaction.created_by == author_id,
                Shout.published_at.is_not(None),
                Shout.deleted_at.is_(None),
                Reaction.deleted_at.is_(None),
            )
        )
    )

    with local_session() as session:
        result = session.execute(q).scalar()
        return int(result) if result else 0


def get_author_followers_stat(author_id: int) -> int:
    """
    Получает количество подписчиков для указанного автора
    """
    q = select(func.count(AuthorFollower.follower)).filter(AuthorFollower.author == author_id)

    with local_session() as session:
        result = session.execute(q).scalar()
        return int(result) if result else 0


def get_author_comments_stat(author_id: int) -> int:
    q = (
        select(func.coalesce(func.count(Reaction.id), 0).label("comments_count"))
        .select_from(Author)
        .outerjoin(
            Reaction,
            and_(
                Reaction.created_by == Author.id,
                Reaction.kind == ReactionKind.COMMENT.value,
                Reaction.deleted_at.is_(None),
            ),
        )
        .where(Author.id == author_id)
        .group_by(Author.id)
    )

    with local_session() as session:
        result = session.execute(q).scalar()
        if result and hasattr(result, "comments_count"):
            return int(result.comments_count)
        return 0


def get_with_stat(q: QueryType) -> list[Any]:
    """
    Выполняет запрос с добавлением статистики.

    :param q: SQL-запрос для выполнения.
    :return: Список объектов с добавленной статистикой.
    """
    records = []
    try:
        with local_session() as session:
            # Определяем, является ли запрос запросом авторов
            author_prefixes = ("select author", "select * from author")
            is_author = f"{q}".lower().startswith(author_prefixes)

            # Добавляем колонки статистики в запрос
            q = add_author_stat_columns(q) if is_author else add_topic_stat_columns(q)

            # Выполняем запрос
            result = session.execute(q).unique()
            for cols in result:
                entity = cols[0]
                stat = {}
                stat["shouts"] = cols[1]  # Статистика по публикациям
                stat["followers"] = cols[2]  # Статистика по подписчикам
                if is_author:
                    # Дополнительная проверка типа entity.id
                    if not hasattr(entity, "id"):
                        logger.error(f"Entity does not have id attribute: {entity}")
                        continue
                    entity_id = entity.id
                    if not isinstance(entity_id, int):
                        logger.error(f"Entity id is not integer: {entity_id} (type: {type(entity_id)})")
                        continue

                    stat["authors"] = get_author_authors_stat(entity_id)  # Статистика по подпискам на авторов
                    stat["comments"] = get_author_comments_stat(entity_id)  # Статистика по комментариям
                else:
                    # Дополнительная проверка типа entity.id для тем
                    if not hasattr(entity, "id"):
                        logger.error(f"Entity does not have id attribute: {entity}")
                        continue
                    entity_id = entity.id
                    if not isinstance(entity_id, int):
                        logger.error(f"Entity id is not integer: {entity_id} (type: {type(entity_id)})")
                        continue

                    stat["authors"] = get_topic_authors_stat(entity_id)  # Статистика по авторам темы
                entity.stat = stat
                records.append(entity)
    except Exception as exc:
        import traceback

        logger.debug(q)
        traceback.print_exc()
        logger.error(exc, exc_info=True)
    return records


def author_follows_authors(author_id: int) -> list[Any]:
    """
    Получает список авторов, на которых подписан указанный автор.

    :param author_id: Идентификатор автора.
    :return: Список авторов с добавленной статистикой.
    """
    af = aliased(AuthorFollower, name="af")
    author_follows_authors_query = (
        select(Author).select_from(join(Author, af, Author.id == af.author)).where(af.follower == author_id)
    )
    return get_with_stat(author_follows_authors_query)


def author_follows_topics(author_id: int) -> list[Any]:
    """
    Получает список тем, на которые подписан указанный автор.

    :param author_id: Идентификатор автора.
    :return: Список тем с добавленной статистикой.
    """
    author_follows_topics_query = (
        select(Topic)
        .select_from(join(Topic, TopicFollower, Topic.id == TopicFollower.topic))
        .where(TopicFollower.follower == author_id)
    )
    return get_with_stat(author_follows_topics_query)


def update_author_stat(author_id: int) -> None:
    """
    Обновляет статистику для указанного автора и сохраняет её в кэше.

    :param author_id: Идентификатор автора.
    """
    author_query = select(Author).where(Author.id == author_id)
    try:
        result = get_with_stat(author_query)
        if result:
            author_with_stat = result[0]
            if isinstance(author_with_stat, Author):
                author_dict = author_with_stat.dict()
                # Асинхронное кэширование данных автора
                task = asyncio.create_task(cache_author(author_dict))
                # Store task reference to prevent garbage collection
                if not hasattr(update_author_stat, "_background_tasks"):
                    update_author_stat._background_tasks = set()  # type: ignore[attr-defined]
                update_author_stat._background_tasks.add(task)  # type: ignore[attr-defined]
                task.add_done_callback(update_author_stat._background_tasks.discard)  # type: ignore[attr-defined]
    except Exception as exc:
        logger.error(exc, exc_info=True)


def get_followers_count(entity_type: str, entity_id: int) -> int:
    """Получает количество подписчиков для сущности"""
    try:
        with local_session() as session:
            if entity_type == "topic":
                result = (
                    session.query(func.count(TopicFollower.follower)).filter(TopicFollower.topic == entity_id).scalar()
                )
            elif entity_type == "author":
                # Count followers of this author
                result = (
                    session.query(func.count(AuthorFollower.follower))
                    .filter(AuthorFollower.author == entity_id)
                    .scalar()
                )
            elif entity_type == "community":
                result = (
                    session.query(func.count(CommunityFollower.follower))
                    .filter(CommunityFollower.community == entity_id)
                    .scalar()
                )
            else:
                return 0

            return int(result) if result else 0
    except Exception as e:
        logger.error(f"Error getting followers count: {e}")
        return 0


def get_following_count(entity_type: str, entity_id: int) -> int:
    """Получает количество подписок сущности"""
    try:
        with local_session() as session:
            if entity_type == "author":
                # Count what this author follows
                topic_follows = (
                    session.query(func.count(TopicFollower.topic)).filter(TopicFollower.follower == entity_id).scalar()
                    or 0
                )
                community_follows = (
                    session.query(func.count(CommunityFollower.community))
                    .filter(CommunityFollower.follower == entity_id)
                    .scalar()
                    or 0
                )
                return int(topic_follows) + int(community_follows)
            return 0
    except Exception as e:
        logger.error(f"Error getting following count: {e}")
        return 0


def get_shouts_count(
    author_id: Optional[int] = None, topic_id: Optional[int] = None, community_id: Optional[int] = None
) -> int:
    """Получает количество публикаций"""
    try:
        with local_session() as session:
            query = session.query(func.count(Shout.id)).filter(Shout.published_at.isnot(None))

            if author_id:
                query = query.filter(Shout.created_by == author_id)
            if topic_id:
                # This would need ShoutTopic association table
                pass
            if community_id:
                query = query.filter(Shout.community == community_id)

            result = query.scalar()
            return int(result) if result else 0
    except Exception as e:
        logger.error(f"Error getting shouts count: {e}")
        return 0


def get_authors_count(community_id: Optional[int] = None) -> int:
    """Получает количество авторов"""
    try:
        with local_session() as session:
            if community_id:
                # Count authors in specific community
                result = (
                    session.query(func.count(distinct(CommunityFollower.follower)))
                    .filter(CommunityFollower.community == community_id)
                    .scalar()
                )
            else:
                # Count all authors
                result = session.query(func.count(Author.id)).filter(Author.deleted == False).scalar()

            return int(result) if result else 0
    except Exception as e:
        logger.error(f"Error getting authors count: {e}")
        return 0


def get_topics_count(author_id: Optional[int] = None) -> int:
    """Получает количество топиков"""
    try:
        with local_session() as session:
            if author_id:
                # Count topics followed by author
                result = (
                    session.query(func.count(TopicFollower.topic)).filter(TopicFollower.follower == author_id).scalar()
                )
            else:
                # Count all topics
                result = session.query(func.count(Topic.id)).scalar()

            return int(result) if result else 0
    except Exception as e:
        logger.error(f"Error getting topics count: {e}")
        return 0


def get_communities_count() -> int:
    """Получает количество сообществ"""
    try:
        with local_session() as session:
            result = session.query(func.count(Community.id)).scalar()
            return int(result) if result else 0
    except Exception as e:
        logger.error(f"Error getting communities count: {e}")
        return 0


def get_reactions_count(shout_id: Optional[int] = None, author_id: Optional[int] = None) -> int:
    """Получает количество реакций"""
    try:
        from orm.reaction import Reaction

        with local_session() as session:
            query = session.query(func.count(Reaction.id))

            if shout_id:
                query = query.filter(Reaction.shout == shout_id)
            if author_id:
                query = query.filter(Reaction.created_by == author_id)

            result = query.scalar()
            return int(result) if result else 0
    except Exception as e:
        logger.error(f"Error getting reactions count: {e}")
        return 0


def get_comments_count_by_shout(shout_id: int) -> int:
    """Получает количество комментариев к статье"""
    try:
        from orm.reaction import Reaction

        with local_session() as session:
            # Using text() to access 'kind' column which might be enum
            result = (
                session.query(func.count(Reaction.id))
                .filter(
                    and_(
                        Reaction.shout == shout_id,
                        Reaction.kind == "comment",  # Assuming 'comment' is a valid enum value
                    )
                )
                .scalar()
            )

            return int(result) if result else 0
    except Exception as e:
        logger.error(f"Error getting comments count: {e}")
        return 0


async def get_stat_background_task() -> None:
    """Фоновая задача для обновления статистики"""
    try:
        if not hasattr(sys.modules[__name__], "_background_tasks"):
            sys.modules[__name__]._background_tasks = set()  # type: ignore[attr-defined]

        # Perform background statistics calculations
        logger.info("Running background statistics update")

        # Here you would implement actual background statistics updates
        # This is just a placeholder

    except Exception as e:
        logger.error(f"Error in background statistics task: {e}")