Fail on flat-filter excluded media

Introduce GamdlDownloaderFlatFilterExcludedError and raise it during AppleMusicDownloader processing when item.media.flat_filter_result is truthy. This aborts further processing/download for media excluded by the flat filter and includes the media id in the error message. Also import the new exception in the downloader module.

gamdl/downloader/downloader.py

@@ -8,6 +8,7 @@ from .constants import TEMP_PATH_TEMPLATE
 from .enums import DownloadMode, RemuxMode
 from .exceptions import (
     GamdlDownloaderDependencyNotFoundError,
+    GamdlDownloaderFlatFilterExcludedError,
     GamdlDownloaderMediaFileExistsError,
     GamdlDownloaderSyncedLyricsOnlyError,
 )
@@ -71,6 +72,11 @@ class AppleMusicDownloader:
             if item.media.error:
                 raise item.media.error
 
+            if item.media.flat_filter_result:
+                raise GamdlDownloaderFlatFilterExcludedError(
+                    item.media.media_metadata["id"]
+                )
+
             await self._initial_processing(item)
             await self._download(item)
             await self._final_processing(item)

gamdl/downloader/exceptions.py

@@ -18,3 +18,8 @@ class GamdlDownloaderMediaFileExistsError(GamdlDownloaderError):
 class GamdlDownloaderDependencyNotFoundError(GamdlDownloaderError):
     def __init__(self, dependency_name: str) -> None:
         super().__init__(f"Required dependency not found: {dependency_name}")
+
+
+class GamdlDownloaderFlatFilterExcludedError(GamdlDownloaderError):
+    def __init__(self, media_id: str) -> None:
+        super().__init__(f"Media is excluded by flat filter: {media_id}")