from datetime import datetime, timedelta, timezone
from typing import Optional

import bcrypt
from jose import JWTError, jwt
from fastapi import Request, HTTPException

from app.config import JWT_SECRET, ACCESS_TOKEN_EXPIRE_MINUTES

ALGORITHM = "HS256"

_token_version_cache: dict[str, int] = {}


def get_cached_token_version(user_id: str) -> int | None:
    return _token_version_cache.get(user_id)


def set_cached_token_version(user_id: str, version: int):
    _token_version_cache[user_id] = version


def hash_password(password: str) -> str:
    return bcrypt.hashpw(password.encode("utf-8"), bcrypt.gensalt()).decode("utf-8")


def verify_password(plain_password: str, hashed_password: str) -> bool:
    return bcrypt.checkpw(plain_password.encode("utf-8"), hashed_password.encode("utf-8"))


def create_access_token(data: dict, expires_delta: Optional[timedelta] = None) -> str:
    to_encode = data.copy()
    expire = datetime.now(timezone.utc) + (expires_delta or timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES))
    to_encode.update({"exp": expire})
    return jwt.encode(to_encode, JWT_SECRET, algorithm=ALGORITHM)


def decode_access_token(token: str) -> dict:
    return jwt.decode(token, JWT_SECRET, algorithms=[ALGORITHM])


def get_current_user(request: Request) -> dict:
    if hasattr(request.state, "user") and request.state.user:
        return request.state.user
    token = request.cookies.get("access_token", "")
    if not token:
        raise HTTPException(status_code=401, detail="未登录")
    try:
        payload = decode_access_token(token)
        return payload
    except JWTError:
        raise HTTPException(status_code=401, detail="登录已过期，请重新登录")