feat(services): add key resolution for orphaned anime folders

- Add key_resolution_service.py to resolve provider keys for folders without key/data files
- Search anime provider and match folder names (case-insensitive, exact match required)
- Only save to DB if exactly one match found; otherwise skip
- Add comprehensive unit tests (28 tests)
- Integrate into scheduler_service after nfo_repair scan
- Update ARCHITECTURE.md documentation

Docker/VERSION

@@ -1 +1 @@
-v1.2.2
+v1.3.0

docs/ARCHITECTURE.md

@@ -293,7 +293,7 @@ The FastAPI lifespan function (`src/server/fastapi_app.py`) runs the following s
 9. Scheduler service started
    +-- Cron-based library rescans configured
    +-- Optional: auto-download missing episodes after rescan
-   +-- Optional: folder maintenance (NFO repair, renaming, poster checks) during scheduled runs
+   +-- Optional: folder maintenance (NFO repair, key resolution, renaming, poster checks) during scheduled runs
 ```
 
 ### 12.2 Temp Folder Guarantee

package.json

@@ -1,6 +1,6 @@
 {
   "name": "aniworld-web",
-  "version": "1.2.2",
+  "version": "1.3.0",
   "description": "Aniworld Anime Download Manager - Web Frontend",
   "type": "module",
   "scripts": {

src/server/services/key_resolution_service.py

@@ -0,0 +1,317 @@
+"""Key resolution service for orphaned anime folders.
+
+Attempts to resolve provider keys for anime folders that have no key/data
+file and no database entry, by searching the anime provider and matching
+folder names to search results.
+
+This service runs after nfo_repair_service during the daily folder scan.
+"""
+from __future__ import annotations
+
+import asyncio
+import re
+from pathlib import Path
+from typing import Optional
+
+import structlog
+
+from src.config.settings import settings as _settings
+
+logger = structlog.get_logger(__name__)
+
+# Limit concurrent provider searches to avoid rate-limiting.
+_SEARCH_SEMAPHORE: asyncio.Semaphore = asyncio.Semaphore(2)
+
+
+def _strip_year_from_folder(folder_name: str) -> str:
+    """Remove trailing year suffix like ' (2020)' from folder name.
+
+    Args:
+        folder_name: Folder name, e.g. 'Rent-A-Girlfriend (2020)'
+
+    Returns:
+        Name without year, e.g. 'Rent-A-Girlfriend'
+    """
+    return re.sub(r"\s*\(\d{4}\)\s*$", "", folder_name).strip()
+
+
+def _extract_year_from_folder(folder_name: str) -> Optional[int]:
+    """Extract year from folder name like 'Anime Name (2020)'.
+
+    Returns:
+        Year as int or None if not present.
+    """
+    match = re.search(r"\((\d{4})\)$", folder_name.strip())
+    if match:
+        return int(match.group(1))
+    return None
+
+
+def _extract_key_from_link(link: str) -> Optional[str]:
+    """Extract provider key from search result link.
+
+    Args:
+        link: Link like '/anime/stream/rent-a-girlfriend' or full URL.
+
+    Returns:
+        Key slug like 'rent-a-girlfriend' or None.
+    """
+    if not link:
+        return None
+    if "/anime/stream/" in link:
+        parts = link.split("/anime/stream/")[-1].split("/")
+        key = parts[0].strip()
+        return key if key else None
+    # If link is just a slug
+    if "/" not in link and link.strip():
+        return link.strip()
+    return None
+
+
+def _normalize_for_comparison(text: str) -> str:
+    """Normalize text for case-insensitive comparison.
+
+    Strips whitespace, lowercases, and removes common punctuation
+    differences that shouldn't affect matching.
+
+    Args:
+        text: Raw text string.
+
+    Returns:
+        Normalized lowercase string.
+    """
+    normalized = text.strip().lower()
+    # Remove common punctuation that varies between sources
+    normalized = re.sub(r"[:\-–—]", " ", normalized)
+    # Collapse multiple spaces
+    normalized = re.sub(r"\s+", " ", normalized)
+    return normalized.strip()
+
+
+async def resolve_key_for_folder(folder_name: str) -> Optional[str]:
+    """Attempt to resolve the provider key for a single folder.
+
+    Strategy:
+    1. Strip year suffix from folder name to get search query.
+    2. Search the anime provider with that query.
+    3. If exactly ONE result matches the folder name (case-insensitive),
+       return the key extracted from the result link.
+    4. If zero or multiple matches, return None (not confident enough).
+
+    Args:
+        folder_name: The anime folder name, e.g. 'Rent-A-Girlfriend (2020)'.
+
+    Returns:
+        The provider key string, or None if resolution is not confident.
+    """
+    search_query = _strip_year_from_folder(folder_name)
+    if not search_query:
+        logger.debug("Empty search query after stripping year from '%s'", folder_name)
+        return None
+
+    async with _SEARCH_SEMAPHORE:
+        try:
+            loop = asyncio.get_running_loop()
+            results = await loop.run_in_executor(None, _search_provider, search_query)
+        except Exception as exc:
+            logger.warning(
+                "Provider search failed for '%s': %s", search_query, exc
+            )
+            return None
+
+    if not results:
+        logger.debug("No search results for folder '%s'", folder_name)
+        return None
+
+    # Filter results: find exact name matches (case-insensitive)
+    normalized_query = _normalize_for_comparison(search_query)
+    exact_matches = []
+
+    for result in results:
+        title = result.get("title") or result.get("name") or ""
+        normalized_title = _normalize_for_comparison(title)
+
+        if normalized_title == normalized_query:
+            key = _extract_key_from_link(result.get("link", ""))
+            if key:
+                exact_matches.append((key, title))
+
+    if len(exact_matches) == 1:
+        resolved_key, matched_title = exact_matches[0]
+        logger.info(
+            "Resolved key for folder '%s': key='%s' (matched title: '%s')",
+            folder_name,
+            resolved_key,
+            matched_title,
+        )
+        return resolved_key
+
+    if len(exact_matches) > 1:
+        logger.info(
+            "Multiple exact matches for folder '%s' (%d matches), skipping",
+            folder_name,
+            len(exact_matches),
+        )
+    else:
+        logger.debug(
+            "No exact title match for folder '%s' in %d results",
+            folder_name,
+            len(results),
+        )
+
+    return None
+
+
+def _search_provider(query: str) -> list:
+    """Call the anime provider search synchronously.
+
+    Args:
+        query: Search term.
+
+    Returns:
+        List of search result dicts with 'link' and 'title'/'name' fields.
+    """
+    from src.core.providers.provider_factory import Loaders
+
+    loader = Loaders().GetLoader("aniworld.to")
+    return loader.search(query)
+
+
+async def perform_key_resolution_scan() -> dict[str, int]:
+    """Scan all anime folders and resolve missing keys.
+
+    Iterates over all subfolders of the anime directory. For each folder
+    that has no corresponding database entry, attempts to resolve the
+    provider key via provider search and saves it to the database.
+
+    Returns:
+        Dictionary with counts:
+        - 'scanned': total folders checked
+        - 'resolved': keys successfully resolved and saved
+        - 'skipped': folders already in DB or resolution uncertain
+        - 'errors': folders that caused errors during resolution
+    """
+    from src.server.database.connection import get_db_session
+    from src.server.database.service import AnimeSeriesService
+
+    stats = {"scanned": 0, "resolved": 0, "skipped": 0, "errors": 0}
+
+    if not _settings.anime_directory:
+        logger.warning("Key resolution scan skipped — anime directory not configured")
+        return stats
+
+    anime_dir = Path(_settings.anime_directory)
+    if not anime_dir.is_dir():
+        logger.warning(
+            "Key resolution scan skipped — anime directory not found: %s",
+            anime_dir,
+        )
+        return stats
+
+    # Collect folders that need resolution
+    folders_to_resolve: list[str] = []
+
+    async with get_db_session() as db:
+        for series_dir in sorted(anime_dir.iterdir()):
+            if not series_dir.is_dir():
+                continue
+            folder_name = series_dir.name
+            stats["scanned"] += 1
+
+            # Check if already in database
+            existing = await AnimeSeriesService.get_by_folder(db, folder_name)
+            if existing:
+                stats["skipped"] += 1
+                continue
+
+            folders_to_resolve.append(folder_name)
+
+    if not folders_to_resolve:
+        logger.info("Key resolution scan: all folders already have DB entries")
+        return stats
+
+    logger.info(
+        "Key resolution scan: %d folders need resolution", len(folders_to_resolve)
+    )
+
+    # Resolve keys one by one (provider search is rate-limited)
+    for folder_name in folders_to_resolve:
+        try:
+            key = await resolve_key_for_folder(folder_name)
+            if key:
+                # Save to database
+                await _save_resolved_key(folder_name, key)
+                stats["resolved"] += 1
+            else:
+                stats["skipped"] += 1
+        except Exception as exc:
+            logger.error(
+                "Error resolving key for folder '%s': %s",
+                folder_name,
+                exc,
+            )
+            stats["errors"] += 1
+
+    logger.info(
+        "Key resolution scan complete: scanned=%d, resolved=%d, skipped=%d, errors=%d",
+        stats["scanned"],
+        stats["resolved"],
+        stats["skipped"],
+        stats["errors"],
+    )
+    return stats
+
+
+async def _save_resolved_key(folder_name: str, key: str) -> None:
+    """Save a resolved key to the database.
+
+    Creates a new AnimeSeries entry with the resolved key and folder name.
+    Does NOT write any key/data file to disk.
+
+    Args:
+        folder_name: The anime folder name (e.g. 'Rent-A-Girlfriend (2020)').
+        key: The resolved provider key (e.g. 'rent-a-girlfriend').
+    """
+    from src.server.database.connection import get_db_session
+    from src.server.database.service import AnimeSeriesService
+
+    name = _strip_year_from_folder(folder_name)
+    year = _extract_year_from_folder(folder_name)
+
+    async with get_db_session() as db:
+        # Double-check: another task might have resolved it concurrently
+        existing = await AnimeSeriesService.get_by_folder(db, folder_name)
+        if existing:
+            logger.debug(
+                "Folder '%s' already in DB (resolved concurrently), skipping",
+                folder_name,
+            )
+            return
+
+        # Also check if a series with this key already exists
+        existing_key = await AnimeSeriesService.get_by_key(db, key)
+        if existing_key:
+            logger.warning(
+                "Key '%s' already exists in DB for folder '%s', "
+                "cannot assign to folder '%s'",
+                key,
+                existing_key.folder,
+                folder_name,
+            )
+            return
+
+        await AnimeSeriesService.create(
+            db,
+            key=key,
+            name=name,
+            site="aniworld.to",
+            folder=folder_name,
+            year=year,
+            loading_status="pending",
+            episodes_loaded=False,
+        )
+        logger.info(
+            "Saved resolved key '%s' for folder '%s' to database",
+            key,
+            folder_name,
+        )

src/server/services/scheduler_service.py

@@ -316,11 +316,9 @@ class SchedulerService:
             return
 
         try:
-            from src.server.database.connection import (  # noqa: PLC0415
-                get_db_session,
-            )
-            from src.server.database.system_settings_service import (  # noqa: PLC0415
-                SystemSettingsService,
+            from src.server.database.connection import get_db_session  # noqa: PLC0415
+            from src.server.database.system_settings_service import (
+                SystemSettingsService,  # noqa: PLC0415
             )
 
             async with get_db_session() as db:
@@ -367,8 +365,8 @@ class SchedulerService:
     async def _broadcast(self, event_type: str, data: dict) -> None:
         """Broadcast a WebSocket event to all connected clients."""
         try:
-            from src.server.services.websocket_service import (  # noqa: PLC0415
-                get_websocket_service,
+            from src.server.services.websocket_service import (
+                get_websocket_service,  # noqa: PLC0415
             )
 
             ws_service = get_websocket_service()
@@ -503,8 +501,8 @@ class SchedulerService:
             if self._config and self._config.folder_scan_enabled:
                 logger.info("Folder scan is enabled — starting")
                 try:
-                    from src.server.services.folder_scan_service import (  # noqa: PLC0415
-                        FolderScanService,
+                    from src.server.services.folder_scan_service import (
+                        FolderScanService,  # noqa: PLC0415
                     )
 
                     folder_scan_service = FolderScanService()
@@ -519,6 +517,26 @@ class SchedulerService:
                     await self._broadcast(
                         "folder_scan_error", {"error": str(fs_exc)}
                     )
+
+                # Key resolution scan (resolve orphaned folders)
+                try:
+                    from src.server.services.key_resolution_service import (
+                        perform_key_resolution_scan,  # noqa: PLC0415
+                    )
+
+                    key_stats = await perform_key_resolution_scan()
+                    logger.info(
+                        "Key resolution scan completed: resolved=%d, skipped=%d, errors=%d",
+                        key_stats["resolved"],
+                        key_stats["skipped"],
+                        key_stats["errors"],
+                    )
+                except Exception as kr_exc:  # pylint: disable=broad-exception-caught
+                    logger.error(
+                        "Key resolution scan failed: %s",
+                        kr_exc,
+                        exc_info=True,
+                    )
             else:
                 logger.debug("Folder scan is disabled — skipping")
 

tests/unit/test_key_resolution_service.py

@@ -0,0 +1,218 @@
+"""Unit tests for key_resolution_service."""
+from __future__ import annotations
+
+from unittest.mock import AsyncMock, MagicMock, patch
+
+import pytest
+
+from src.server.services.key_resolution_service import (
+    _extract_key_from_link,
+    _extract_year_from_folder,
+    _normalize_for_comparison,
+    _strip_year_from_folder,
+    resolve_key_for_folder,
+)
+
+
+class TestStripYearFromFolder:
+    """Tests for _strip_year_from_folder."""
+
+    def test_removes_year_suffix(self):
+        assert _strip_year_from_folder("Rent-A-Girlfriend (2020)") == "Rent-A-Girlfriend"
+
+    def test_removes_year_suffix_with_spaces(self):
+        assert _strip_year_from_folder("Attack on Titan (2013)") == "Attack on Titan"
+
+    def test_no_year_returns_original(self):
+        assert _strip_year_from_folder("Naruto") == "Naruto"
+
+    def test_year_in_middle_not_stripped(self):
+        assert _strip_year_from_folder("2024 Anime (2024)") == "2024 Anime"
+
+    def test_empty_string(self):
+        assert _strip_year_from_folder("") == ""
+
+    def test_only_year(self):
+        assert _strip_year_from_folder("(2020)") == ""
+
+
+class TestExtractYearFromFolder:
+    """Tests for _extract_year_from_folder."""
+
+    def test_extracts_year(self):
+        assert _extract_year_from_folder("Rent-A-Girlfriend (2020)") == 2020
+
+    def test_no_year_returns_none(self):
+        assert _extract_year_from_folder("Naruto") is None
+
+    def test_year_in_middle_not_extracted(self):
+        # Only trailing year is extracted
+        assert _extract_year_from_folder("2024 Anime") is None
+
+
+class TestExtractKeyFromLink:
+    """Tests for _extract_key_from_link."""
+
+    def test_relative_link(self):
+        assert _extract_key_from_link("/anime/stream/rent-a-girlfriend") == "rent-a-girlfriend"
+
+    def test_full_url(self):
+        assert (
+            _extract_key_from_link("https://aniworld.to/anime/stream/attack-on-titan")
+            == "attack-on-titan"
+        )
+
+    def test_link_with_trailing_slash(self):
+        assert _extract_key_from_link("/anime/stream/naruto/") == "naruto"
+
+    def test_empty_link(self):
+        assert _extract_key_from_link("") is None
+
+    def test_none_link(self):
+        assert _extract_key_from_link(None) is None
+
+    def test_slug_only(self):
+        assert _extract_key_from_link("one-piece") == "one-piece"
+
+
+class TestNormalizeForComparison:
+    """Tests for _normalize_for_comparison."""
+
+    def test_case_insensitive(self):
+        assert _normalize_for_comparison("Rent-A-Girlfriend") == _normalize_for_comparison(
+            "rent-a-girlfriend"
+        )
+
+    def test_strips_whitespace(self):
+        assert _normalize_for_comparison("  Naruto  ") == "naruto"
+
+    def test_normalizes_dashes(self):
+        assert _normalize_for_comparison("Rent-A-Girlfriend") == "rent a girlfriend"
+
+    def test_collapses_spaces(self):
+        assert _normalize_for_comparison("Attack  on   Titan") == "attack on titan"
+
+
+class TestResolveKeyForFolder:
+    """Tests for resolve_key_for_folder."""
+
+    @pytest.mark.asyncio
+    async def test_single_exact_match_returns_key(self):
+        """When provider returns exactly one exact-name match, key is resolved."""
+        search_results = [
+            {"link": "/anime/stream/rent-a-girlfriend", "title": "Rent-A-Girlfriend"},
+        ]
+
+        with patch(
+            "src.server.services.key_resolution_service._search_provider",
+            return_value=search_results,
+        ):
+            key = await resolve_key_for_folder("Rent-A-Girlfriend (2020)")
+            assert key == "rent-a-girlfriend"
+
+    @pytest.mark.asyncio
+    async def test_no_results_returns_none(self):
+        """When provider returns no results, returns None."""
+        with patch(
+            "src.server.services.key_resolution_service._search_provider",
+            return_value=[],
+        ):
+            key = await resolve_key_for_folder("Unknown Anime (2020)")
+            assert key is None
+
+    @pytest.mark.asyncio
+    async def test_multiple_exact_matches_returns_none(self):
+        """When multiple results match the same name exactly, returns None."""
+        search_results = [
+            {"link": "/anime/stream/my-anime", "title": "My Anime"},
+            {"link": "/anime/stream/my-anime-2", "title": "My Anime"},
+        ]
+
+        with patch(
+            "src.server.services.key_resolution_service._search_provider",
+            return_value=search_results,
+        ):
+            key = await resolve_key_for_folder("My Anime (2022)")
+            assert key is None
+
+    @pytest.mark.asyncio
+    async def test_no_exact_match_returns_none(self):
+        """When results exist but none match the folder name, returns None."""
+        search_results = [
+            {"link": "/anime/stream/rent-a-girlfriend-2", "title": "Rent-A-Girlfriend 2nd Season"},
+            {"link": "/anime/stream/rent-a-girlfriend-3", "title": "Rent-A-Girlfriend 3rd Season"},
+        ]
+
+        with patch(
+            "src.server.services.key_resolution_service._search_provider",
+            return_value=search_results,
+        ):
+            key = await resolve_key_for_folder("Rent-A-Girlfriend (2020)")
+            assert key is None
+
+    @pytest.mark.asyncio
+    async def test_case_insensitive_match(self):
+        """Matching is case-insensitive."""
+        search_results = [
+            {"link": "/anime/stream/naruto", "title": "NARUTO"},
+        ]
+
+        with patch(
+            "src.server.services.key_resolution_service._search_provider",
+            return_value=search_results,
+        ):
+            key = await resolve_key_for_folder("Naruto (2002)")
+            assert key == "naruto"
+
+    @pytest.mark.asyncio
+    async def test_provider_error_returns_none(self):
+        """When provider search raises an exception, returns None gracefully."""
+        with patch(
+            "src.server.services.key_resolution_service._search_provider",
+            side_effect=RuntimeError("Network error"),
+        ):
+            key = await resolve_key_for_folder("Some Anime (2020)")
+            assert key is None
+
+    @pytest.mark.asyncio
+    async def test_result_with_name_field_instead_of_title(self):
+        """Search results using 'name' field instead of 'title' work."""
+        search_results = [
+            {"link": "/anime/stream/one-piece", "name": "One Piece"},
+        ]
+
+        with patch(
+            "src.server.services.key_resolution_service._search_provider",
+            return_value=search_results,
+        ):
+            key = await resolve_key_for_folder("One Piece (1999)")
+            assert key == "one-piece"
+
+    @pytest.mark.asyncio
+    async def test_folder_without_year(self):
+        """Folders without year suffix still work."""
+        search_results = [
+            {"link": "/anime/stream/naruto", "title": "Naruto"},
+        ]
+
+        with patch(
+            "src.server.services.key_resolution_service._search_provider",
+            return_value=search_results,
+        ):
+            key = await resolve_key_for_folder("Naruto")
+            assert key == "naruto"
+
+    @pytest.mark.asyncio
+    async def test_exact_match_among_partial_matches(self):
+        """Only exact matches count, partial matches are ignored."""
+        search_results = [
+            {"link": "/anime/stream/dororo", "title": "Dororo"},
+            {"link": "/anime/stream/dororo-to-hyakkimaru", "title": "Dororo to Hyakkimaru"},
+        ]
+
+        with patch(
+            "src.server.services.key_resolution_service._search_provider",
+            return_value=search_results,
+        ):
+            key = await resolve_key_for_folder("Dororo (2019)")
+            assert key == "dororo"