from fastapi import Depends, HTTPException, status
from fastapi.security import HTTPAuthorizationCredentials, HTTPBearer
from sqlalchemy.ext.asyncio import AsyncSession

from app.models.base import async_session
from app.models.user import User
from app.services.auth import decode_access_token
from sqlalchemy import select

security = HTTPBearer(auto_error=False)


async def get_db():
    async with async_session() as session:
        try:
            yield session
            await session.commit()
        except Exception:
            await session.rollback()
            raise
        finally:
            await session.close()


async def get_current_user(
    credentials: HTTPAuthorizationCredentials | None = Depends(security),
    db: AsyncSession = Depends(get_db),
) -> User:
    if not credentials:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="未登录",
        )

    user_id = decode_access_token(credentials.credentials)
    if not user_id:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="登录已过期",
        )

    # Skip captcha tokens
    if user_id.startswith("captcha:"):
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="无效的凭证",
        )

    result = await db.execute(select(User).where(User.id == user_id))
    user = result.scalar_one_or_none()
    if not user or not user.is_active:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="账号不存在或已禁用",
        )
    return user


async def get_admin_user(
    current_user: User = Depends(get_current_user),
) -> User:
    if not current_user.is_admin or current_user.user_type != "admin":
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="需要管理员权限",
        )
    return current_user