import time

from collections.abc import Awaitable, Callable
from typing import Any

from aiogram import BaseMiddleware
from aiogram.types import Message, Update
from sqlalchemy.ext.asyncio import AsyncSession

from config import DISABLE_DIRECT_START
from core.bootstrap import MODES_CONFIG
from database import check_user_exists
from logger import logger


_TTL = 20
_cache_user_exists: dict[int, tuple[float, bool]] = {}


class DirectStartBlockerMiddleware(BaseMiddleware):
    def __init__(self) -> None:
        self.allowed_prefixes = ("gift_", "referral_", "coupons_", "utm", "partner_")

    async def __call__(
        self,
        handler: Callable[[Update, dict[str, Any]], Awaitable[Any]],
        event: Update,
        data: dict[str, Any],
    ) -> Any:
        direct_start_disabled = bool(MODES_CONFIG.get("DIRECT_START_DISABLED", DISABLE_DIRECT_START))
        if not direct_start_disabled:
            return await handler(event, data)

        message: Message | None = getattr(event, "message", None)
        if not message or not message.text:
            return await handler(event, data)

        fsm = data.get("state")
        if fsm:
            current_state = await fsm.get_state()
            if current_state:
                return await handler(event, data)

        session = data.get("session")
        if not isinstance(session, AsyncSession):
            return await handler(event, data)

        tg_id = message.from_user.id
        text = message.text.strip()
        now = time.time()
        user_in_data = bool(data.get("user"))

        async def user_exists_cached() -> bool:
            if user_in_data:
                return True

            cached = _cache_user_exists.get(tg_id)
            if cached and cached[0] > now:
                return cached[1]

            exists = await check_user_exists(session, tg_id)
            _cache_user_exists[tg_id] = (now + _TTL, exists)
            return exists

        if not text.startswith("/"):
            if await user_exists_cached():
                return await handler(event, data)
            return

        parts = text.split(maxsplit=1)
        if parts[0] != "/start":
            if await user_exists_cached():
                return await handler(event, data)
            logger.info(
                f"[DirectStartBlocker] Команда '{text}' отклонена для незарегистрированного пользователя {tg_id}"
            )
            return

        if len(parts) == 1:
            if await user_exists_cached():
                return await handler(event, data)
            logger.info(f"[DirectStartBlocker] Прямой старт запрещён для нового пользователя {tg_id}")
            return

        start_param = parts[1].strip()
        if not start_param or not start_param.startswith(self.allowed_prefixes):
            if await user_exists_cached():
                return await handler(event, data)
            logger.info(f"[DirectStartBlocker] Отклонена неизвестная ссылка от {tg_id}: {start_param!r}")
            return

        logger.info(f"[DirectStartBlocker] Разрешённая ссылка от {tg_id}: {start_param!r}")
        return await handler(event, data)