draft: streaming the audio

music_kraken/download/page_attributes.py

@@ -16,6 +16,7 @@ from ..objects import (
     Artist,
     Label,
 )
+from ..audio import write_metadata_to_target, correct_codec
 from ..utils.string_processing import fit_to_file_system
 from ..utils.config import youtube_settings, main_settings
 from ..utils.path_manager import LOCATIONS
@@ -125,15 +126,10 @@ class Pages:
         return data_object
 
     def fetch_from_source(self, source: Source, **kwargs) -> Optional[DataObject]:
-        page: Page = self._get_page_from_enum(source.source_type)
-        if page is None:
+        if not source.has_page:
             return None
         
-        # getting the appropriate function for the page and the object type
-        source_type = page.get_source_type(source)
-        if not hasattr(page, fetch_map[source_type]):
-            return None
-        func = getattr(page, fetch_map[source_type])(source=source, **kwargs)
+        func = getattr(source.page, fetch_map[source_type])(source=source, **kwargs)
         
         # fetching the data object and marking it as fetched
         data_object: DataObject = func(source=source)
@@ -215,11 +211,6 @@ class Pages:
 
         return possible_parts
 
-    def _get_pages_with_source(self, data_object: DataObject, sort_by_attribute: str = "DOWNLOAD_PRIORITY") -> List[Page]:
-        pages = [self._get_page_from_enum(s.source_type) for s in data_object.source_collection.get_sources()]
-        pages.sort(key=lambda p: getattr(p, sort_by_attribute), reverse=True)
-        return list(pages)
-
     def _download_song(self, song: Song, naming: dict) -> DownloadOptions:
         """
         TODO
@@ -248,7 +239,6 @@ class Pages:
 
         # manage the targets
         tmp: Target = Target.temp(file_extension=main_settings["audio_format"])
-        found_on_disc = False
 
         song.target_collection.append(Target(
             relative_to_music_dir=True,
@@ -260,17 +250,39 @@ class Pages:
         for target in song.target_collection:
             if target.exists():
                 output(f'- {target.file_path} {BColors.OKGREEN.value}[already exists]', color=BColors.GREY)
-
-                found_on_disc = True
                 r.found_on_disk += 1
-                target.copy_content(tmp)
+
+                if self.download_options.download_again_if_found:
+                    target.copy_content(tmp)
             else:
                 target.create_parent_directories()
                 output(f'- {target.file_path}', color=BColors.GREY)
 
-        # actually download
-        for page in self._get_pages_with_source(song, sort_by_attribute="DOWNLOAD_PRIORITY"):
-            r = page.download_song_to_target(song, tmp, r)
+        # this streams from every available source until something succeeds, setting the skip intervals to the values of the according source
+        used_source: Optional[Source] = None
+        skip_intervals: List[Tuple[float, float]] = []
+        for source in song.source_collection.get_sources(source_type_sorting={
+            "only_with_page": True,
+            "sort_key": lambda page: page.download_priority,
+            "reverse": True,
+        }):
+            if tmp.exists:
+                break
+
+            used_source = source
+            streaming_results = source.page.download_song_to_target(source=source, target=tmp, desc="download")
+            skip_intervals = source.page.get_skip_intervals(song=song, source=source)
+
+            # if something has been downloaded but it somehow failed, delete the file
+            if streaming_results.is_fatal_error and tmp.exists:
+                tmp.delete()
+
+        # if everything went right, the file should exist now
+        if not tmp.exists:
+            r.error_message = f"The song {song.option_string} couldn't be downloaded."
+            return r
+
+        # post process the audio
 
         return r