from collections.abc import Generator
from typing import Annotated

import jwt
from fastapi import Depends, HTTPException, status
from fastapi.security import OAuth2PasswordBearer
from jwt.exceptions import InvalidTokenError
from pydantic import ValidationError
from sqlmodel import Session

from app.core import security
from app.core.config import settings
from app.core.db import engine
from app.models import TokenPayload, User

reusable_oauth2 = OAuth2PasswordBearer(
    tokenUrl=f"{settings.API_V1_STR}/login/access-token"
)


def get_db() -> Generator[Session, None, None]:
    with Session(engine) as session:
        yield session


SessionDep = Annotated[Session, Depends(get_db)]
TokenDep = Annotated[str, Depends(reusable_oauth2)]


def get_current_user(session: SessionDep, token: TokenDep) -> User:
    try:
        payload = jwt.decode(
            token, settings.SECRET_KEY, algorithms=[security.ALGORITHM]
        )
        token_data = TokenPayload(**payload)
    except (InvalidTokenError, ValidationError):
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="无法验证凭据",
        )
    user = session.get(User, token_data.sub)
    if not user:
        raise HTTPException(status_code=404, detail="用户未找到")
    if not user.is_active:
        raise HTTPException(status_code=400, detail="用户未激活")
    return user


CurrentUser = Annotated[User, Depends(get_current_user)]


def get_current_active_superuser(current_user: CurrentUser) -> User:
    if not current_user.is_superuser:
        raise HTTPException(
            status_code=403, detail="用户权限不足"
        )
    return current_user