"""Recommendation freshness contracts."""
from __future__ import annotations

import shutil
from pathlib import Path

import pytest

from backend.core import Backend

_SEED = Path(__file__).resolve().parent.parent / "deploy/hf/seed/hf_bundled_store.db"


@pytest.mark.skipif(not _SEED.is_file(), reason="bundled seed DB not present")
def test_saved_recommendation_kink_must_not_appear_in_following_recommend_list(tmp_path: Path) -> None:
    """Fails when HTTP cache is not invalidated on play save (stale deck still lists the saved kink)."""
    dest = tmp_path / "rec_inval.db"
    shutil.copyfile(_SEED, dest)
    b = Backend(dest)
    u = b.create_user()
    first = b.recommend(u.id, limit=8)
    kid = first[0]["kink"]["id"]
    b.save_play_preference(u.id, kid, "like", ["together"])
    after = b.recommend(u.id, limit=8)
    ids = {x["kink"]["id"] for x in after}
    assert kid not in ids, "saved kink must be excluded after invalidate + recompute"


@pytest.mark.skipif(not _SEED.is_file(), reason="bundled seed DB not present")
def test_recommendations_are_fresh_without_http_response_cache(tmp_path: Path) -> None:
    """Back-to-back stochastic lists may differ, but must stay valid and uncached."""
    dest = tmp_path / "rec_fresh.db"
    shutil.copyfile(_SEED, dest)
    b = Backend(dest)
    u = b.create_user()
    a = b.recommend(u.id, limit=8)
    b2 = b.recommend(u.id, limit=8)
    assert a and b2
    for batch in (a, b2):
        ids = [x["kink"]["id"] for x in batch]
        assert len(ids) == len(set(ids))
        assert not (set(ids) & set(b.get_user(u.id)["plays"]))
    assert not hasattr(b, "_recommend_http_cache")


@pytest.mark.skipif(not _SEED.is_file(), reason="bundled seed DB not present")
def test_play_board_lists_dual_direction_play_in_to_me_and_by_me(tmp_path: Path) -> None:
    """Server board must place one play in every active direction bucket (regression guard)."""
    dest = tmp_path / "board_dual.db"
    shutil.copyfile(_SEED, dest)
    b = Backend(dest)
    u = b.create_user()
    kid = next(iter(b._catalog()["detail_by_id"]))
    b.save_play_preference(u.id, kid, "like", ["to_me", "by_me"])
    board = b.play_board(u.id)
    to_me = {x["id"] for x in board["to_me"]}
    by_me = {x["id"] for x in board["by_me"]}
    assert kid in to_me and kid in by_me