"""Regression tests for the recipe empty-prune guard (issue #1116).

A scan that finds no recipe files at all is not a trustworthy deletion signal:
an unmounted drive, a ``recipes_path`` that silently fell back to another LoRA
root, or a cache shared with a second instance all look identical to a real
wipe. Before this guard, such a scan overwrote the persistent cache with an
empty one, destroying the user's only record of their recipes.

Covered contracts:

1. ``_reconcile_recipe_cache`` reports the "every persisted file vanished"
   condition and does not treat an empty directory as a trustworthy prune.
2. ``_initialize_recipe_cache_sync`` keeps the stored cache in that case
   instead of persisting the empty result.
3. A partial orphan (some files still present) still prunes normally, so
   ordinary manual deletions keep working.
4. ``PersistentRecipeCache.save_cache(skip_if_empty=True)`` is the
   storage-level backstop and a manual rebuild can still clear the cache.
"""

from __future__ import annotations

import json
import logging
from pathlib import Path
from types import SimpleNamespace

import pytest

from py.config import config
from py.services import recipe_scanner as recipe_scanner_module
from py.services import settings_manager as settings_manager_module
from py.services.persistent_recipe_cache import (
    PersistedRecipeData,
    PersistentRecipeCache,
)
from py.services.recipe_cache import RecipeCache
from py.services.recipe_scanner import RecipeScanner


def _write_recipe_json(path: Path, recipe_id: str) -> None:
    path.parent.mkdir(parents=True, exist_ok=True)
    path.write_text(
        json.dumps(
            {
                "id": recipe_id,
                "file_path": str(path.with_suffix(".png")),
                "title": f"Recipe {recipe_id}",
                "modified": 0.0,
                "created_date": 0.0,
                "loras": [],
            }
        ),
        encoding="utf-8",
    )


def _persisted_for(paths: list[Path]) -> PersistedRecipeData:
    """Build persisted cache state describing *paths* as known recipe files."""
    raw_data = []
    file_stats = {}
    for path in paths:
        recipe_id = path.name[: -len(".recipe.json")]
        raw_data.append({"id": recipe_id, "title": f"Recipe {recipe_id}"})
        stat = path.stat()
        file_stats[str(path)] = (stat.st_mtime, stat.st_size)
    return PersistedRecipeData(
        raw_data=raw_data, file_stats=file_stats, image_id_map={}
    )


@pytest.fixture
def guard_scanner(tmp_path: Path, monkeypatch):
    """RecipeScanner wired to a real persistent cache, without a ComfyUI app."""
    RecipeScanner._instance = None
    settings_manager_module.reset_settings_manager()
    monkeypatch.setattr(config, "loras_roots", [str(tmp_path / "loras-root")])

    scanner = RecipeScanner.__new__(RecipeScanner)
    scanner._persistent_cache = PersistentRecipeCache(
        db_path=str(tmp_path / "recipe_cache.sqlite")
    )
    scanner._cache = None
    scanner._json_path_map = {}
    scanner._lora_scanner = SimpleNamespace()

    yield scanner, scanner._persistent_cache

    RecipeScanner._instance = None
    settings_manager_module.reset_settings_manager()


def test_reconcile_flags_prune_when_every_persisted_file_is_gone(
    guard_scanner, tmp_path: Path
):
    """An empty recipes dir must not be reported as a trustworthy prune."""
    scanner, _cache = guard_scanner
    recipes_dir = tmp_path / "recipes"
    recipes_dir.mkdir()

    # The files used to live at another root (a changed recipes_path) and are
    # all gone from the directory the scanner resolved this time.
    old_files = [tmp_path / "elsewhere" / f"r{idx}.recipe.json" for idx in range(3)]
    for path in old_files:
        _write_recipe_json(path, path.name[: -len(".recipe.json")])
    persisted = _persisted_for(old_files)
    for path in old_files:
        path.unlink()

    recipes, changed, json_paths, skipped_prune_reason = (
        scanner._reconcile_recipe_cache(persisted, str(recipes_dir))
    )

    assert recipes == []
    assert json_paths == {}
    assert changed is True
    assert skipped_prune_reason is not None
    assert str(recipes_dir) in skipped_prune_reason
    assert "3" in skipped_prune_reason


def test_reconcile_prunes_normally_when_only_some_files_disappear(
    guard_scanner, tmp_path: Path
):
    """A partial orphan is an ordinary deletion and keeps its old behaviour."""
    scanner, _cache = guard_scanner
    recipes_dir = tmp_path / "recipes"

    survivor = recipes_dir / "survivor.recipe.json"
    _write_recipe_json(survivor, "survivor")
    vanished = recipes_dir / "vanished.recipe.json"
    _write_recipe_json(vanished, "vanished")
    persisted = _persisted_for([survivor, vanished])
    vanished.unlink()

    recipes, changed, _json_paths, skipped_prune_reason = (
        scanner._reconcile_recipe_cache(persisted, str(recipes_dir))
    )

    assert skipped_prune_reason is None
    assert changed is True
    assert [recipe["id"] for recipe in recipes] == ["survivor"]


def test_reconcile_ignores_empty_persisted_cache(guard_scanner, tmp_path: Path):
    """A genuinely empty cache has nothing to lose and must not be guarded."""
    scanner, _cache = guard_scanner
    recipes_dir = tmp_path / "recipes"
    recipes_dir.mkdir()

    persisted = PersistedRecipeData(raw_data=[], file_stats={}, image_id_map={})

    _recipes, changed, _json_paths, skipped_prune_reason = (
        scanner._reconcile_recipe_cache(persisted, str(recipes_dir))
    )

    assert changed is False
    assert skipped_prune_reason is None


def test_reconcile_prunes_when_stored_metadata_is_inconsistent(
    guard_scanner, tmp_path: Path
):
    """A stale row set must not masquerade as a fresh mass disappearance.

    Leftover rows (rows without a recorded file stat) mean the stored cache is
    already out of date; guarding them would preserve orphans forever.
    """
    scanner, _cache = guard_scanner
    recipes_dir = tmp_path / "recipes"
    recipes_dir.mkdir()

    gone = tmp_path / "old-location" / "kept.recipe.json"
    _write_recipe_json(gone, "kept")
    persisted = _persisted_for([gone])
    gone.unlink()
    # A row with no matching file record: the cache diverged at some point.
    persisted.raw_data.append({"id": "orphan-row", "title": "Orphan"})

    recipes, changed, _json_paths, skipped_prune_reason = (
        scanner._reconcile_recipe_cache(persisted, str(recipes_dir))
    )

    assert recipes == []
    assert changed is True
    assert skipped_prune_reason is None


def test_sync_init_keeps_stored_cache_when_scan_finds_nothing(
    guard_scanner, tmp_path: Path, caplog: pytest.LogCaptureFixture
):
    """The startup path must not overwrite the stored cache with an empty one."""
    scanner, cache = guard_scanner
    recipes_dir = Path(config.loras_roots[0]) / "recipes"
    gone = tmp_path / "old-location" / "kept.recipe.json"
    _write_recipe_json(gone, "kept")

    assert cache.save_cache(
        [{"id": "kept", "title": "Recipe kept"}], {"kept": str(gone)}
    )
    gone.unlink()

    with caplog.at_level(logging.WARNING, logger=recipe_scanner_module.__name__):
        scanner._initialize_recipe_cache_sync()

    assert "Recipe cache prune skipped" in caplog.text
    assert scanner._prune_skipped is True
    # The stored cache survived, so the recipes remain recoverable.
    persisted = cache.load_cache()
    assert persisted is not None
    assert [recipe["id"] for recipe in persisted.raw_data] == ["kept"]


def test_skipped_prune_leaves_fts_index_untouched(guard_scanner, tmp_path: Path):
    """A skipped prune must not rebuild the FTS index from the empty view."""
    scanner, cache = guard_scanner
    gone = tmp_path / "old-location" / "kept.recipe.json"
    _write_recipe_json(gone, "kept")
    assert cache.save_cache(
        [{"id": "kept", "title": "Recipe kept"}], {"kept": str(gone)}
    )
    gone.unlink()

    schedule_calls = []
    scanner._schedule_fts_index_build = lambda: schedule_calls.append(True)

    scanner._initialize_recipe_cache_sync()

    assert scanner._prune_skipped is True
    assert schedule_calls == []


def test_sync_init_persists_when_recipes_are_found(guard_scanner, tmp_path: Path):
    """The guard must not block a normal successful scan."""
    scanner, cache = guard_scanner
    recipes_dir = Path(config.loras_roots[0]) / "recipes"
    _write_recipe_json(recipes_dir / "fresh.recipe.json", "fresh")

    scanner._initialize_recipe_cache_sync()

    persisted = cache.load_cache()
    assert persisted is not None
    assert [recipe["id"] for recipe in persisted.raw_data] == ["fresh"]


def test_save_cache_skip_if_empty_preserves_existing_rows(tmp_path: Path):
    """The storage-level backstop refuses to empty a populated cache."""
    cache = PersistentRecipeCache(db_path=str(tmp_path / "recipe_cache.sqlite"))
    assert cache.save_cache([{"id": "r1", "title": "One"}], {"r1": "/tmp/r1.json"})

    written = cache.save_cache([], {}, skip_if_empty=True)

    assert written is False
    persisted = cache.load_cache()
    assert persisted is not None
    assert [recipe["id"] for recipe in persisted.raw_data] == ["r1"]


def test_save_cache_skip_if_empty_allows_clearing_an_empty_cache(tmp_path: Path):
    """Nothing to protect: an already-empty cache still returns success."""
    cache = PersistentRecipeCache(db_path=str(tmp_path / "recipe_cache.sqlite"))

    assert cache.save_cache([], {}, skip_if_empty=True) is True


def test_save_cache_default_still_allows_intentional_full_clear(tmp_path: Path):
    """A manual rebuild passes skip_if_empty=False and must clear the cache."""
    cache = PersistentRecipeCache(db_path=str(tmp_path / "recipe_cache.sqlite"))
    assert cache.save_cache([{"id": "r1", "title": "One"}], {"r1": "/tmp/r1.json"})

    assert cache.save_cache([], {}) is True

    persisted = cache.load_cache()
    assert persisted is None or persisted.raw_data == []