from datetime import datetime, timedelta
from typing import Annotated

from fastapi import Depends, HTTPException, status
from fastapi.security import HTTPAuthorizationCredentials, HTTPBearer
from jose import JWTError, jwt
from passlib.context import CryptContext
from sqlalchemy.orm import Session

from app.config import settings
from app.database import get_db
from app.models import User

pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")
bearer = HTTPBearer(auto_error=False)


def hash_password(password: str) -> str:
    return pwd_context.hash(password)


def verify_password(plain: str, hashed: str) -> bool:
    return pwd_context.verify(plain, hashed)


def create_access_token(user_id: int, role: str) -> str:
    expire = datetime.utcnow() + timedelta(hours=settings.jwt_expire_hours)
    payload = {"sub": str(user_id), "role": role, "exp": expire}
    return jwt.encode(payload, settings.jwt_secret, algorithm=settings.jwt_algorithm)


def get_current_user(
    creds: Annotated[HTTPAuthorizationCredentials | None, Depends(bearer)],
    db: Annotated[Session, Depends(get_db)],
) -> User:
    if not creds or not creds.credentials:
        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="未登录")
    try:
        payload = jwt.decode(
            creds.credentials, settings.jwt_secret, algorithms=[settings.jwt_algorithm]
        )
        user_id = int(payload.get("sub", 0))
    except (JWTError, ValueError):
        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="无效令牌")
    user = db.get(User, user_id)
    if not user or not user.is_active:
        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="用户不可用")
    return user


def require_admin(user: Annotated[User, Depends(get_current_user)]) -> User:
    if user.role != "admin":
        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="需要管理员权限")
    return user