"""FastAPI dependencies: DB, current user, admin-only."""
from __future__ import annotations

from typing import AsyncIterator

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

from app.core.security import decode_access_token
from app.db import get_db_dep
from app.models import User

oauth2_scheme = OAuth2PasswordBearer(tokenUrl="/api/auth/login", auto_error=False)


async def get_current_user(
    token: str | None = Depends(oauth2_scheme),
    db: AsyncSession = Depends(get_db_dep),
) -> User:
    if not token:
        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="missing_token")
    payload = decode_access_token(token)
    if not payload or payload.get("type") != "access":
        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="invalid_token")
    user_id = payload.get("sub")
    if not user_id:
        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="invalid_token")
    result = await db.execute(select(User).where(User.id == user_id))
    user = result.scalars().first()
    if not user or not user.is_active:
        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="user_not_found")
    return user


async def require_admin(user: User = Depends(get_current_user)) -> User:
    if not user.is_admin:
        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="admin_required")
    return user