import asyncio
import hashlib
import secrets
import logging
from datetime import datetime, timedelta
from typing import Dict, Optional

from config.settings import settings

logger = logging.getLogger(__name__)

ADMIN_PASSWORD = settings.ADMIN_PASSWORD


class AuthManager:
    """Управляет авторизацией: хеширование паролей, сессии, верификация, роли."""

    def __init__(self, session_timeout_minutes: int = 120):
        self._sessions: Dict[int, datetime] = {}
        self._roles: Dict[int, str] = {}  # user_id -> "admin" or "user"
        self._failed_attempts: Dict[int, list] = {}
        self._max_attempts = 5
        self._lockout_duration = 300
        self._session_timeout = timedelta(minutes=session_timeout_minutes)

    @staticmethod
    def _hash_password(password: str, salt: str = None) -> tuple:
        if salt is None:
            salt = secrets.token_hex(16)
        result = hashlib.sha256((salt + password).encode()).hexdigest()
        return result, salt

    def verify_password(self, password: str, password_hash: str, salt: str) -> bool:
        computed, _ = self._hash_password(password, salt)
        return secrets.compare_digest(computed, password_hash)

    def is_authenticated(self, user_id: int) -> bool:
        if user_id not in self._sessions:
            return False
        # Обычные пользователи — сессия бесконечная
        if self._roles.get(user_id) != "admin":
            return True
        # Админы — таймаут применяется
        if datetime.now() - self._sessions[user_id] > self._session_timeout:
            self.logout(user_id)
            return False
        return True

    def is_admin(self, user_id: int) -> bool:
        return self._roles.get(user_id) == "admin"

    def login(self, user_id: int, is_admin: bool = False):
        self._sessions[user_id] = datetime.now()
        self._roles[user_id] = "admin" if is_admin else "user"
        self._failed_attempts.pop(user_id, None)
        logger.info(f"User {user_id} logged in as {self._roles[user_id]}")

    def logout(self, user_id: int):
        self._sessions.pop(user_id, None)
        self._roles.pop(user_id, None)
        self._failed_attempts.pop(user_id, None)
        logger.info(f"User {user_id} logged out")

    def is_locked_out(self, user_id: int) -> bool:
        if user_id not in self._failed_attempts:
            return False
        attempts = self._failed_attempts[user_id]
        recent = [t for t in attempts if datetime.now() - t < timedelta(minutes=5)]
        self._failed_attempts[user_id] = recent
        if len(recent) >= self._max_attempts:
            return True
        return False

    def record_failed_attempt(self, user_id: int):
        if user_id not in self._failed_attempts:
            self._failed_attempts[user_id] = []
        self._failed_attempts[user_id].append(datetime.now())

    def get_session_info(self, user_id: int) -> Optional[dict]:
        if user_id not in self._sessions:
            return None
        login_time = self._sessions[user_id]
        elapsed = datetime.now() - login_time
        return {
            "user_id": user_id,
            "login_time": login_time.isoformat(),
            "elapsed_minutes": int(elapsed.total_seconds() // 60),
        }