Refactor AppleMusic download flow for synced lyrics only

gamdl/downloader/downloader.py

@@ -337,9 +337,6 @@ class AppleMusicDownloader:
 
     async def download(self, download_item: DownloadItem | Exception) -> None:
         try:
-            if isinstance(download_item, Exception):
-                raise download_item
-
             await self._download(download_item)
             if not self.base_downloader.skip_processing:
                 await self._final_processing(download_item)
@@ -349,8 +346,13 @@ class AppleMusicDownloader:
 
     async def _download(
         self,
-        download_item: DownloadItem,
+        download_item: DownloadItem | Exception,
     ) -> None:
+        if isinstance(download_item, Exception):
+            raise download_item
+        if self.song_downloader.synced_lyrics_only:
+            return
+
         if (
             Path(download_item.final_path).exists()
             and not self.base_downloader.overwrite
@@ -396,7 +398,7 @@ class AppleMusicDownloader:
         self,
         download_item: DownloadItem,
     ) -> None:
-        if Path(download_item.staged_path).exists():
+        if download_item.staged_path and Path(download_item.staged_path).exists():
             self.base_downloader.move_to_final_path(
                 download_item.staged_path,
                 download_item.final_path,

gamdl/downloader/downloader_song.py

@@ -46,8 +46,6 @@ class AppleMusicSongDownloader:
             song_metadata,
             self.synced_lyrics_format,
         )
-        if self.synced_lyrics_only:
-            return download_item
 
         webplayback = await self.downloader.apple_music_api.get_webplayback(song_id)
         download_item.media_tags = self.song_interface.get_tags(
@@ -64,6 +62,18 @@ class AppleMusicSongDownloader:
                 download_item.playlist_tags,
             )
 
+        download_item.final_path = self.downloader.get_final_path(
+            download_item.media_tags,
+            ".m4a",
+            download_item.playlist_tags,
+        )
+        download_item.synced_lyrics_path = self.get_lyrics_synced_path(
+            download_item.final_path,
+        )
+
+        if self.synced_lyrics_only:
+            return download_item
+
         if self.codec.is_legacy():
             download_item.stream_info = (
                 await self.song_interface.get_stream_info_legacy(
@@ -106,14 +116,6 @@ class AppleMusicSongDownloader:
             "staged",
             "." + download_item.stream_info.file_format.value,
         )
-        download_item.final_path = self.downloader.get_final_path(
-            download_item.media_tags,
-            ".m4a",
-            download_item.playlist_tags,
-        )
-        download_item.synced_lyrics_path = self.get_lyrics_synced_path(
-            download_item.final_path,
-        )
         cover_file_extension = await self.downloader.get_cover_file_extension(
             download_item.cover_url_template,
         )