from fastapi import Depends, HTTPException, status
from fastapi.security import OAuth2PasswordBearer
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy import select

from app.database import get_db
from app.models.user import User
from app.services.auth import decode_token


oauth2_scheme = OAuth2PasswordBearer(tokenUrl="/api/auth/login")


async def get_current_user(
    token: str = Depends(oauth2_scheme),
    db: AsyncSession = Depends(get_db),
) -> User:
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": "Bearer"},
    )

    payload = decode_token(token)
    if payload is None:
        raise credentials_exception

    user_id_str: str | None = payload.get("sub")
    if user_id_str is None:
        raise credentials_exception

    try:
        user_id = int(user_id_str)
    except (ValueError, TypeError):
        raise credentials_exception

    result = await db.execute(select(User).where(User.id == user_id))
    user = result.scalar_one_or_none()

    if user is None:
        raise credentials_exception

    if not user.is_active:
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="Inactive user",
        )

    return user


async def get_current_admin(
    current_user: User = Depends(get_current_user),
) -> User:
    if current_user.role != "admin":
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="Admin access required",
        )
    return current_user