from __future__ import annotations

from dataclasses import dataclass

from fastapi import Depends, Header, HTTPException, status
from sqlalchemy.orm import Session

from app.db.models import ApiKey, User
from app.db.session import get_session
from app.security.api_keys import authenticate_api_key, has_scope


@dataclass(slots=True)
class ApiPrincipal:
    api_key: ApiKey
    user: User
    tenant_id: str


def _extract_api_key(authorization: str | None, x_api_key: str | None) -> str | None:
    if x_api_key:
        return x_api_key.strip()
    if authorization and authorization.lower().startswith("bearer "):
        return authorization[7:].strip()
    return None


def get_api_principal(
    session: Session = Depends(get_session),
    authorization: str | None = Header(default=None),
    x_api_key: str | None = Header(default=None, alias="X-API-Key"),
) -> ApiPrincipal:
    secret = _extract_api_key(authorization, x_api_key)
    if not secret:
        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="Missing API key")
    api_key = authenticate_api_key(session, secret)
    if not api_key:
        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="Invalid API key")
    user = session.get(User, api_key.user_id)
    if not user or not user.is_active:
        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="Inactive user")
    session.commit()
    return ApiPrincipal(api_key=api_key, user=user, tenant_id=api_key.tenant_id)


def require_scope(required_scope: str):
    def dependency(principal: ApiPrincipal = Depends(get_api_principal)) -> ApiPrincipal:
        if not has_scope(principal.api_key, required_scope):
            raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail=f"Missing scope: {required_scope}")
        return principal

    return dependency