from fastapi import Depends, HTTPException, status, Request
from sqlalchemy.orm import Session
from jose import JWTError

from app.core.database import get_db
from app.core.security import decode_token
from app.models.user import User
from app.services import user_service


def get_token_from_request(request: Request) -> str:
    auth = request.headers.get("Authorization", "")
    if auth.startswith("Bearer "):
        return auth[7:]
    # Fallback to query param for some special cases
    token = request.query_params.get("token")
    if token:
        return token
    raise HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="缺少认证令牌",
        headers={"WWW-Authenticate": "Bearer"},
    )


def get_current_user(
    request: Request,
    db: Session = Depends(get_db),
) -> User:
    token = get_token_from_request(request)
    payload = decode_token(token)
    if not payload:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="无效的认证令牌",
            headers={"WWW-Authenticate": "Bearer"},
        )
    user = user_service.get_user_by_id(db, int(payload.get("sub")))
    if not user:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="用户不存在")
    if not user.is_active:
        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="用户已被禁用")
    return user


def get_current_active_user(
    current_user: User = Depends(get_current_user),
) -> User:
    return current_user