refactor: Restructure GUI components into separate modules for improved maintainability

tidal_dl_ng/gui/track_extras.py

@@ -0,0 +1,74 @@
+"""Track extras mixin for MainWindow.
+
+Handles track extras caching and retrieval.
+"""
+
+import contextlib
+from collections.abc import Callable
+
+from PySide6 import QtCore
+
+from tidal_dl_ng.helper.tidal import extract_contributor_names, fetch_raw_track_and_album, parse_track_and_album_extras
+from tidal_dl_ng.worker import Worker
+
+
+class TrackExtrasMixin:
+    """Mixin containing track extras management methods."""
+
+    def get_track_extras(self, track_id: str, callback: Callable[[str, dict | None], None]) -> dict | None:
+        """Return cached extras for a track or start async fetch."""
+        cached = self.track_extras_cache.get(track_id)
+        if cached is not None:
+            return cached
+
+        if track_id in self._pending_extras_workers:
+            return None
+
+        if callback:
+            self._track_extras_callbacks[track_id] = callback
+
+        def worker() -> None:
+            extras = None
+            try:
+                track_json, album_json = fetch_raw_track_and_album(self.tidal.session, track_id)
+                extras = parse_track_and_album_extras(track_json, album_json)
+                extras = self._decorate_extras(extras)
+                self.track_extras_cache.set(track_id, extras)
+            except Exception:
+                extras = None
+            finally:
+                self._pending_extras_workers.pop(track_id, None)
+                self.s_track_extras_ready.emit(track_id, extras)
+                self.s_invoke_callback.emit(track_id, extras)
+
+        worker_obj = Worker(worker)
+        self._pending_extras_workers[track_id] = worker_obj
+        self.threadpool.start(worker_obj)
+        return None
+
+    @QtCore.Slot(str, object)
+    def _on_invoke_callback(self, track_id: str, extras: dict | None) -> None:
+        """Invoke the stored callback for a track in the main thread."""
+        callback = self._track_extras_callbacks.pop(track_id, None)
+        if callback:
+            with contextlib.suppress(Exception):
+                callback(track_id, extras)
+
+    def _decorate_extras(self, extras: dict | None) -> dict:
+        """Add formatted string fields to extras dict."""
+        if not extras:
+            return {}
+        result = dict(extras)
+        result["genres_text"] = ", ".join(result.get("genres", []))
+        for role, key in [
+            ("producer", "producers_text"),
+            ("composer", "composers_text"),
+            ("lyricist", "lyricists_text"),
+        ]:
+            result[key] = extract_contributor_names(result.get("contributors_by_role"), role)
+        return result
+
+    def preload_covers_for_playlist(self, items: list) -> None:
+        """Preload cover pixmaps for a list of tracks in background."""
+        if self.cover_manager:
+            self.cover_manager.preload_covers_for_playlist(items)