"""Shared API dependencies: current user extraction from JWT."""

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

from app.core.database import get_db
from app.core.exceptions import ForbiddenError, UnauthorizedError
from app.core.security import decode_token
from app.models.user import User

bearer_scheme = HTTPBearer(auto_error=False)


async def get_current_user(
    credentials: HTTPAuthorizationCredentials | None = Depends(bearer_scheme),
    db: AsyncSession = Depends(get_db),
) -> User:
    if credentials is None:
        raise UnauthorizedError("Authorization header fehlt")
    payload = decode_token(credentials.credentials)
    username = payload.get("sub")
    if not username:
        raise UnauthorizedError("Token enthält keinen Benutzer")

    from sqlalchemy import select

    result = await db.execute(select(User).where(User.username == username))
    user = result.scalar_one_or_none()
    if not user or not user.is_active:
        raise UnauthorizedError("Benutzer unbekannt oder deaktiviert")
    return user


async def require_admin(user: User = Depends(get_current_user)) -> User:
    if not user.is_admin:
        raise ForbiddenError("Administratorrechte erforderlich")
    return user


def client_ip(request: Request) -> str | None:
    return request.client.host if request.client else None