from __future__ import annotations

from typing import Any

from fastapi import APIRouter, Depends, HTTPException, Query
from sqlalchemy.orm import Session

from ...diff import compute_diff, filter_by_owner
from ...snapshot import Snapshot
from .. import models
from ..db import get_db

router = APIRouter(tags=["diff"])


@router.get("/diff")
def get_diff(
    old: int = Query(..., description="older snapshot id"),
    new: int = Query(..., description="newer snapshot id"),
    owner: str | None = Query(None, description="restrict to one class, e.g. CMC_Animo"),
    db: Session = Depends(get_db),
) -> dict[str, Any]:
    a = db.get(models.Snapshot, old)
    b = db.get(models.Snapshot, new)
    if a is None or b is None:
        raise HTTPException(404, "snapshot not found")
    diff = compute_diff(Snapshot(a.data), Snapshot(b.data))
    if owner:
        diff = filter_by_owner(diff, owner)
    return diff