Rework Tagger fork into Curator movie-library manager (PySide6 GUI, pool index, ČSFD import)

src/core/pool_index.py

@@ -0,0 +1,64 @@
+"""
+Unified metadata index for the Curator pool.
+
+Instead of one sidecar file per movie, the whole pool keeps a single JSON index
+at ``<pool>/.Curator.!index``. Curator owns the pool (it inserts/removes files
+itself), so files never move behind its back and a central index is safe.
+
+Records are keyed by the file's path relative to the pool root (POSIX form),
+e.g. ``"Filmy/Matrix.mkv"`` — stable and portable across machines.
+"""
+import json
+from pathlib import Path
+
+INDEX_FILENAME = ".Curator.!index"
+
+
+class PoolIndex:
+    """Single-file JSON metadata store for all files in a pool."""
+
+    def __init__(self, pool_dir: Path) -> None:
+        self.pool_dir = Path(pool_dir)
+        self.index_path = self.pool_dir / INDEX_FILENAME
+        self.records: dict[str, dict] = {}
+        self.load()
+
+    def _key(self, file_path: Path) -> str:
+        """Pool-relative POSIX key for a file path."""
+        path = Path(file_path)
+        try:
+            return path.relative_to(self.pool_dir).as_posix()
+        except ValueError:
+            return path.as_posix()
+
+    def load(self) -> None:
+        """Load the index from disk (missing/corrupt index = empty)."""
+        if not self.index_path.exists():
+            self.records = {}
+            return
+        try:
+            with open(self.index_path, "r", encoding="utf-8") as f:
+                data = json.load(f)
+            self.records = data.get("movies", {})
+        except (json.JSONDecodeError, OSError):
+            self.records = {}
+
+    def save(self) -> None:
+        """Persist the index to disk."""
+        self.pool_dir.mkdir(parents=True, exist_ok=True)
+        with open(self.index_path, "w", encoding="utf-8") as f:
+            json.dump({"movies": self.records}, f, indent=2, ensure_ascii=False)
+
+    def get(self, file_path: Path) -> dict | None:
+        """Return the record for a file, or None if it is not indexed."""
+        return self.records.get(self._key(file_path))
+
+    def set(self, file_path: Path, data: dict) -> None:
+        """Upsert a record and persist the index."""
+        self.records[self._key(file_path)] = data
+        self.save()
+
+    def delete(self, file_path: Path) -> None:
+        """Remove a record (if present) and persist the index."""
+        if self.records.pop(self._key(file_path), None) is not None:
+            self.save()