from sqlalchemy import delete, func, insert, select, update
from sqlalchemy.exc import SQLAlchemyError
from sqlalchemy.ext.asyncio import AsyncSession

from core.cache_config import SERVERS_CACHE_TTL_SEC
from core.redis_cache import cache_delete_pattern, cache_get, cache_key, cache_set
from database.models import Key, Server, ServerSpecialgroup, ServerSubgroup, Tariff
from logger import logger


async def _invalidate_servers_cache() -> None:
    await cache_delete_pattern("servers:*")


async def create_server(
    session: AsyncSession,
    cluster_name: str,
    server_name: str,
    api_url: str,
    subscription_url: str,
    inbound_id: str,
):
    try:
        stmt = insert(Server).values(
            cluster_name=cluster_name,
            server_name=server_name,
            api_url=api_url,
            subscription_url=subscription_url,
            inbound_id=inbound_id,
        )
        await session.execute(stmt)
        await session.commit()
        await _invalidate_servers_cache()
        logger.info(f"✅ Сервер {server_name} добавлен в кластер {cluster_name}")
    except SQLAlchemyError as e:
        logger.error(f"❌ Ошибка при добавлении сервера {server_name}: {e}")
        await session.rollback()
        raise


async def delete_server(session: AsyncSession, server_name: str):
    try:
        stmt = delete(Server).where(Server.server_name == server_name)
        await session.execute(stmt)
        await session.commit()
        await _invalidate_servers_cache()
        logger.info(f"🗑 Сервер {server_name} удалён")
    except SQLAlchemyError as e:
        logger.error(f"❌ Ошибка при удалении сервера {server_name}: {e}")
        await session.rollback()
        raise


async def get_servers(session: AsyncSession, include_enabled: bool = False) -> dict:
    from handlers.utils import ALLOWED_GROUP_CODES

    cache_key_servers = cache_key("servers", int(include_enabled))
    cached = await cache_get(cache_key_servers)
    if isinstance(cached, dict):
        return cached

    try:
        stmt = select(Server)
        result = await session.execute(stmt)
        servers = result.scalars().all()

        ids = [s.id for s in servers]
        subs_map = {}
        tariffs_map = {}
        if ids:
            r = await session.execute(
                select(ServerSubgroup.server_id, ServerSubgroup.subgroup_title).where(ServerSubgroup.server_id.in_(ids))
            )
            for sid, sg in r.all():
                if sg and sg.isdigit():
                    tariffs_map.setdefault(sid, []).append(int(sg))
                else:
                    subs_map.setdefault(sid, []).append(sg)

        groups_map = {}
        if ids:
            r2 = await session.execute(
                select(ServerSpecialgroup.server_id, ServerSpecialgroup.group_code).where(
                    ServerSpecialgroup.server_id.in_(ids)
                )
            )
            for sid, gc in r2.all():
                groups_map.setdefault(sid, []).append(gc)

        allowed = set(ALLOWED_GROUP_CODES)

        grouped = {}
        for s in servers:
            if not include_enabled and not s.enabled:
                continue
            cluster = s.cluster_name
            special = sorted({g for g in groups_map.get(s.id, []) if g in allowed})
            grouped.setdefault(cluster, []).append({
                "server_name": s.server_name,
                "api_url": s.api_url,
                "subscription_url": s.subscription_url,
                "inbound_id": s.inbound_id,
                "panel_type": s.panel_type,
                "enabled": s.enabled,
                "max_keys": s.max_keys,
                "tariff_group": s.tariff_group,
                "tariff_subgroups": subs_map.get(s.id, []),
                "tariff_ids": tariffs_map.get(s.id, []),
                "special_groups": special,
                "cluster_name": cluster,
                "server_id": s.id,
            })
        await cache_set(cache_key_servers, grouped, SERVERS_CACHE_TTL_SEC)
        return grouped
    except SQLAlchemyError as e:
        logger.error(f"Ошибка при получении серверов: {e}")
        await session.rollback()
        return {}


async def get_clusters(session: AsyncSession) -> list[str]:
    stmt = select(Server.cluster_name).distinct().order_by(Server.cluster_name)
    result = await session.execute(stmt)
    return [r[0] for r in result.all()]


async def check_unique_server_name(session: AsyncSession, server_name: str, cluster_name: str | None = None) -> bool:
    stmt = select(Server).where(Server.server_name == server_name)
    if cluster_name:
        stmt = stmt.where(Server.cluster_name == cluster_name)
    result = await session.execute(stmt.limit(1))
    return result.scalar_one_or_none() is None


async def check_server_name_by_cluster(session: AsyncSession, server_name: str) -> dict | None:
    try:
        result = await session.execute(select(Server.cluster_name).where(Server.server_name == server_name))
        row = result.first()
        return {"cluster_name": row[0]} if row else None
    except SQLAlchemyError as e:
        logger.error(f"Ошибка при поиске кластера для сервера {server_name}: {e}")
        await session.rollback()
        return None


async def get_cluster_name_by_server(session: AsyncSession, server_id_or_name: str) -> str | None:
    stmt = (
        select(Server.cluster_name)
        .where((Server.id == server_id_or_name) | (Server.server_name == server_id_or_name))
        .limit(1)
    )

    result = await session.execute(stmt)
    row = result.scalar_one_or_none()
    return row


async def get_server_by_name(session: AsyncSession, server_name: str) -> dict | None:
    try:
        stmt = select(Server).where(Server.server_name == server_name)
        result = await session.execute(stmt)
        server = result.scalar_one_or_none()

        if server:
            return {
                "id": server.id,
                "cluster_name": server.cluster_name,
                "server_name": server.server_name,
                "api_url": server.api_url,
                "subscription_url": server.subscription_url,
                "inbound_id": server.inbound_id,
                "panel_type": server.panel_type,
                "enabled": server.enabled,
                "max_keys": server.max_keys,
                "tariff_group": server.tariff_group,
            }
        return None
    except SQLAlchemyError as e:
        logger.error(f"Ошибка при получении сервера {server_name}: {e}")
        await session.rollback()
        return None


async def update_server_field(session: AsyncSession, server_name: str, field: str, value: any) -> bool:
    try:
        stmt = update(Server).where(Server.server_name == server_name).values(**{field: value})
        await session.execute(stmt)
        await session.commit()
        await _invalidate_servers_cache()
        logger.info(f"✅ Поле {field} сервера {server_name} обновлено на {value}")
        return True
    except SQLAlchemyError as e:
        logger.error(f"❌ Ошибка при обновлении поля {field} сервера {server_name}: {e}")
        await session.rollback()
        return False


async def update_server_name_with_keys(session: AsyncSession, old_name: str, new_name: str) -> bool:
    try:
        from sqlalchemy import update

        from database.models import Key

        if not await check_unique_server_name(session, new_name):
            logger.error(f"❌ Сервер с именем {new_name} уже существует")
            return False

        stmt_server = update(Server).where(Server.server_name == old_name).values(server_name=new_name)
        await session.execute(stmt_server)

        stmt_keys = update(Key).where(Key.server_id == old_name).values(server_id=new_name)
        await session.execute(stmt_keys)

        await session.commit()
        await _invalidate_servers_cache()
        logger.info(f"✅ Сервер переименован с {old_name} на {new_name}")
        return True
    except SQLAlchemyError as e:
        logger.error(f"❌ Ошибка при переименовании сервера {old_name}: {e}")
        await session.rollback()
        return False


async def get_available_clusters(session: AsyncSession) -> list[str]:
    try:
        stmt = select(Server.cluster_name).distinct().order_by(Server.cluster_name)
        result = await session.execute(stmt)
        return [row[0] for row in result.all()]
    except SQLAlchemyError as e:
        logger.error(f"Ошибка при получении списка кластеров: {e}")
        await session.rollback()
        return []


async def update_server_cluster(session: AsyncSession, server_name: str, new_cluster: str) -> bool:
    try:
        server_data = await get_server_by_name(session, server_name)
        if not server_data:
            return False

        old_cluster = server_data["cluster_name"]

        stmt_remaining = select(func.count()).where(
            (Server.cluster_name == old_cluster) & (Server.server_name != server_name)
        )
        result = await session.execute(stmt_remaining)
        remaining_servers = result.scalar_one()

        if remaining_servers == 0:
            stmt_update_keys = update(Key).where(Key.server_id == old_cluster).values(server_id=new_cluster)
            await session.execute(stmt_update_keys)

        stmt_new_cluster = select(Server.tariff_group).where(Server.cluster_name == new_cluster).limit(1)
        result = await session.execute(stmt_new_cluster)
        new_tariff_group = result.scalar_one_or_none()

        await session.execute(
            update(Server)
            .where(Server.server_name == server_name)
            .values(cluster_name=new_cluster, tariff_group=new_tariff_group)
        )

        if server_data.get("id") is None:
            rid = await session.execute(select(Server.id).where(Server.server_name == server_name).limit(1))
            server_id = rid.scalar_one_or_none()
        else:
            server_id = server_data["id"]

        if server_id is not None and new_tariff_group is not None:
            await session.execute(
                update(ServerSubgroup).where(ServerSubgroup.server_id == server_id).values(group_code=new_tariff_group)
            )

        await session.commit()
        await _invalidate_servers_cache()
        logger.info(
            f"✅ Сервер {server_name} перемещен в кластер {new_cluster} с обновлением тарифной группы и привязок подгрупп"
        )
        return True
    except SQLAlchemyError as e:
        logger.error(f"❌ Ошибка при обновлении кластера сервера {server_name}: {e}")
        await session.rollback()
        return False


async def resolve_device_limit_from_group(session: AsyncSession, server_id: str) -> int | None:
    r = await session.execute(select(Server.tariff_group).where(Server.server_name == server_id))
    group = r.scalar_one_or_none()
    if not group:
        return None
    q = await session.execute(
        select(Tariff.device_limit)
        .where(Tariff.group_code == group, Tariff.is_active.is_(True))
        .order_by(Tariff.duration_days.desc())
        .limit(1)
    )
    dl = q.scalar_one_or_none()
    return int(dl) if dl is not None else None


async def filter_cluster_by_subgroup(
    session: AsyncSession,
    cluster: list,
    target_subgroup: str,
    cluster_id: str,
    tariff_id: int | None = None,
) -> list:
    names = [s.get("server_name") for s in cluster if s.get("server_name")]
    if not names:
        return []

    if tariff_id:
        tariff_id_str = str(tariff_id)
        q_by_tariff = await session.execute(
            select(Server.server_name)
            .join(ServerSubgroup, ServerSubgroup.server_id == Server.id)
            .where(
                Server.server_name.in_(names),
                Server.enabled.is_(True),
                ServerSubgroup.subgroup_title == tariff_id_str,
            )
        )
        allowed_by_tariff = {n for (n,) in q_by_tariff.all()}
        if allowed_by_tariff:
            logger.debug(f"Найдены серверы по tariff_id={tariff_id}: {allowed_by_tariff}")
            return [s for s in cluster if s.get("server_name") in allowed_by_tariff]

    q_allowed = await session.execute(
        select(Server.server_name)
        .join(ServerSubgroup, ServerSubgroup.server_id == Server.id)
        .where(
            Server.server_name.in_(names),
            Server.enabled.is_(True),
            ServerSubgroup.subgroup_title == target_subgroup,
        )
    )
    allowed = {n for (n,) in q_allowed.all()}
    if allowed:
        return [s for s in cluster if s.get("server_name") in allowed]

    check_values = [target_subgroup]
    if tariff_id:
        check_values.append(str(tariff_id))

    total_bindings = await session.scalar(
        select(func.count()).select_from(ServerSubgroup).where(ServerSubgroup.subgroup_title.in_(check_values))
    )
    if not total_bindings:
        logger.info(f"Для подгруппы/тарифа нет привязок. Используем весь кластер {cluster_id}.")
        return cluster

    q_any = await session.execute(
        select(Server.server_name)
        .join(ServerSubgroup, ServerSubgroup.server_id == Server.id)
        .where(
            Server.server_name.in_(names),
            Server.enabled.is_(True),
        )
    )
    any_bound = {n for (n,) in q_any.all()}
    if any_bound:
        logger.warning(f"Нет серверов под подгруппу {target_subgroup} в кластере {cluster_id}.")
        return []

    logger.info(f"В кластере {cluster_id} нет привязок. Используем весь кластер.")
    return cluster


async def filter_cluster_by_tariff(session: AsyncSession, cluster: list, tariff_id: int, cluster_id: str) -> list:
    names = [s.get("server_name") for s in cluster if s.get("server_name")]
    if not names:
        return []

    tariff_id_str = str(tariff_id)

    q_allowed = await session.execute(
        select(Server.server_name)
        .join(ServerSubgroup, ServerSubgroup.server_id == Server.id)
        .where(
            Server.server_name.in_(names),
            Server.enabled.is_(True),
            ServerSubgroup.subgroup_title == tariff_id_str,
        )
    )
    allowed = {n for (n,) in q_allowed.all()}
    if allowed:
        return [s for s in cluster if s.get("server_name") in allowed]

    total_for_tariff = await session.scalar(
        select(func.count()).select_from(ServerSubgroup).where(ServerSubgroup.subgroup_title == tariff_id_str)
    )
    if not total_for_tariff:
        logger.info(f"Для тарифа {tariff_id} нет привязок серверов. Используем весь кластер {cluster_id}.")
        return cluster

    q_any = await session.execute(
        select(Server.server_name)
        .join(ServerSubgroup, ServerSubgroup.server_id == Server.id)
        .where(
            Server.server_name.in_(names),
            Server.enabled.is_(True),
        )
    )
    any_bound = {n for (n,) in q_any.all()}
    if any_bound:
        logger.warning(f"Нет серверов под тариф {tariff_id} в кластере {cluster_id}.")
        return []

    logger.info(f"В кластере {cluster_id} нет привязок тарифов. Используем весь кластер.")
    return cluster


async def has_legacy_subgroup_bindings(session: AsyncSession, server_ids: list[int]) -> bool:
    if not server_ids:
        return False

    result = await session.execute(
        select(ServerSubgroup.subgroup_title).where(ServerSubgroup.server_id.in_(server_ids))
    )
    for (title,) in result.all():
        if title and not title.isdigit():
            return True
    return False