Refactor: unify YDL object and proxy cfg field

This would allow to add sites much simplier
or even drop the ydl_fn_keys.
Main purpose of the refactoring is a code cleanup.

backend/config.py

@@ -20,11 +20,8 @@ class Config:
             os.getenv('TRACK_FILE_TMPL') or '%(track)S.%(ext)s',
         )
 
-        # Proxy URL for yt_proxied downloader (can be used for geo-restricted content)
+        # `or None` -- defaults to None also if PROXY is an empty string
-        self.yt_proxy = os.getenv('YT_PROXY') or None
+        self.proxy = os.getenv('PROXY') or None
-
-        # Proxy for soundcloud
-        self.sc_proxy = os.getenv('SC_PROXY') or None
 
         self.save_lyrics = _parse_bool(os.getenv('SAVE_LYRICS'), True)
         self.save_cover = _parse_bool(os.getenv('SAVE_COVER'), True)

backend/id3pp.py

@@ -10,19 +10,24 @@ import genius
 ENC_UTF8 = 3
 
 
-class InfoYouTubePP(PostProcessor):
+class InfoGenPP(PostProcessor):
-    '''Generates YT Music fields in info if necessary.
+    '''Generates track, artist(s), album, track_number fields
+    from other info fields if they are not present in current info dict.
     Must be run before downloading and post-processing with
-    FFmpegExtractAudioPP and ID3YouTubePP, so use only with
+    FFmpegExtractAudioPP and ID3TagsPP, so use only with
-    when<="before_dl" ("pre_process" also suits, see yt_dlp.utils.POSTPROCESS_WHEN)
+    when="pre_process" for correct file path and ID3 tags'''
-    for correct file path and ID3 tags'''
 
     def run(self, information):
 
         if not 'track' in information:
             information['track'] = information['title']
         if not 'artist' in information:
-            information['artist'] = information['uploader'].removesuffix(' - Topic')
+            artist = information['uploader'].removesuffix(' - Topic')
+            # <Really-dumb-fix>
+            if artist == 'LINKIN PARK':
+                artist = 'Linkin Park'
+            # </Really-dumb-fix>
+            information['artist'] = artist
         if not 'artists' in information:
             information['artists'] = [information['artist']]
 
@@ -44,8 +49,8 @@ class InfoYouTubePP(PostProcessor):
 
 
 class ID3TagsPP(PostProcessor):
-    '''Inserts ID3 tags after all PPs (for YT: InfoYouTubePP and FFmpegExtractAudioPP),
+    '''Inserts ID3 tags including lyrics (see parser in backend/genius.py).
-    triggers searching and parsing lyrics from Genius'''
+    Must be run after all PPs ()'''
 
     def __init__(self) -> None:
         self.cfg = config.get()

backend/main.py

@@ -30,21 +30,19 @@ async def handler(socket: SocketT) -> None:
 
         try:
             data = json.loads(message)
+            print(data)
 
             match data['action']:
 
                 case 'list':  # list tracks in album
-                    ydls.choose_ydl(data['site'])
+                    ydls.update_params(data['site'], data.get('proxy', False))
                     await socket.send(response.playlist(
                         await ydls.get_playlist_items(data['url']),
                     ))
 
                 case 'download':  # download by URL
-                    ydls.choose_ydl(data['site'])
+                    ydls.update_params(data['site'], data.get('proxy', False), data.get('items'))
-                    ret = await ydls.download(
+                    ret = await ydls.download(data['url'])
-                        data['url'],
-                        data.get('items'),
-                    )
                     await socket.send(response.ydl_end(ret))
 
                 case _:
@@ -57,6 +55,8 @@ async def handler(socket: SocketT) -> None:
             if not socket.closed:
                 await socket.send(response.error(ex))
 
+        ydls.reset_params()
+
     ydls.cleanup()
 
 

backend/test_pp.py

@@ -15,7 +15,7 @@ TEST_MP3 = 'music/test.mp3'
 INFO_BEFORE = {
     "filepath": TEST_MP3,
     "title": "A Line in the Sand",
-    "channel": "Linkin Park - Topic",
+    "uploader": "Linkin Park - Topic",
     "playlist": "Album \u2013 The Hunting Party",
     "playlist_index": 12,
     "release_year": 2015,
@@ -44,7 +44,7 @@ class TestPostProcessorsOnFakeData(TestCase):
 
     def test_infoytpp(self) -> None:
 
-        _, info = id3pp.InfoYouTubePP().run(INFO_BEFORE)
+        _, info = id3pp.InfoGenPP().run(INFO_BEFORE)
         self.assertDictEqual(info, INFO_AFTER)
 
     def test_id3(self) -> None:

backend/ydl_pool.py

@@ -10,46 +10,7 @@ import response
 import id3pp
 
 
-class _CreateYDL:
+ydl_fn_keys = {'youtube', 'yandex', 'soundcloud'}
-
-    @staticmethod
-    def youtube() -> YoutubeDL:
-        ydl = YoutubeDL({'format': 'ba'})
-        ydl.add_post_processor(id3pp.InfoYouTubePP(), when='before_dl')
-        ydl.add_post_processor(FFmpegExtractAudioPP(preferredcodec='mp3'), when='post_process')
-        return ydl
-
-    @staticmethod
-    def yt_proxied() -> YoutubeDL:
-        ydl = _CreateYDL.youtube()
-        proxy = config.get().yt_proxy
-        if proxy is not None:
-            ydl.params['proxy'] = proxy
-        return ydl
-
-    @staticmethod
-    def soundcloud() -> YoutubeDL:
-        ydl = YoutubeDL({'format': 'ba[ext=mp3]/ba'})
-        ydl.add_post_processor(id3pp.InfoYouTubePP(), when='pre_process')
-        proxy = config.get().sc_proxy
-        if proxy is not None:
-            ydl.params['proxy'] = proxy
-        ydl.add_post_processor(FFmpegExtractAudioPP(preferredcodec='mp3'), when='post_process')
-        return ydl
-
-    @staticmethod
-    def yandex() -> YoutubeDL:
-        return YoutubeDL()
-
-
-create_ydl_fn = {
-    'youtube': _CreateYDL.youtube,
-    'yt_proxied': _CreateYDL.yt_proxied,
-    'soundcloud': _CreateYDL.soundcloud,
-    'yandex': _CreateYDL.yandex,
-}
-
-ydl_fn_keys = create_ydl_fn.keys()
 
 # need process=True for track title in extract_info output
 NP_YDLS = {'yandex', 'soundcloud'}
@@ -83,98 +44,90 @@ class Downloader:
 
     def __init__(self, logger: YdlLogger | None = None) -> None:
 
-        self.ydls: dict[str, YoutubeDL | None] = {
+        self.cfg = config.get()
-            key: None
-            for key in ydl_fn_keys
-        }
 
-        self.cur_ydl: YoutubeDL | None = None
+        self.ydl = YoutubeDL({'format': 'ba[ext=mp3]/ba/b'})
-        self.cur_site = ''
+        self.ydl.add_post_processor(id3pp.InfoGenPP(), when='pre_process')
+        # Note: it skips converting if downloaded file is already MP3
+        self.ydl.add_post_processor(FFmpegExtractAudioPP(preferredcodec='mp3'), when='post_process')
+        # ID3 tags are set after all pre/post-processings
+        self.ydl.add_post_processor(id3pp.ID3TagsPP(), when='post_process')
 
-        self.id3pp_obj = id3pp.ID3TagsPP()
+        if logger is not None:
+            self.ydl.params['logger'] = logger
 
-        self.logger = logger
+        self.ydl.params['outtmpl']['default'] = self.cfg.tmpl
 
-    def choose_ydl(self, site: str) -> None:
+        self.need_process = False
+        self.updated_params = []
 
-        ydl = self.ydls[site]
+    def update_params(
-        cfg = config.get()
+            self,
+            site: str,
+            proxy: bool = False,
+            items: Iterable[int] | None = None) -> None:
 
-        if ydl is None:
+        self.need_process = site in NP_YDLS
-            ydl = create_ydl_fn[site]()
 
-            if self.logger is not None:
+        cookies = self.cfg.cookies_dir / (site + '.txt')
-                ydl.params['logger'] = self.logger
+        if cookies.exists():
+            self.ydl.params['cookiefile'] = str(cookies)
+            self.updated_params.append('cookiefile')
 
-            ydl.params['outtmpl']['default'] = cfg.tmpl
+        if proxy and self.cfg.proxy is not None:
-            ydl.add_post_processor(self.id3pp_obj, when='post_process')
+            self.ydl.params['proxy'] = self.cfg.proxy
+            self.updated_params.append('proxy')
 
-            cookies = cfg.cookies_dir / (site + '.txt')
+        if items:
-            if cookies.exists():
+            self.ydl.params['playlist_items'] = (
-                ydl.params['cookiefile'] = str(cookies)
+                ','.join(str(i) for i in items)
+            )
+            self.updated_params.append('playlist_items')
 
-        self.cur_ydl = ydl
+    def reset_params(self) -> None:
-        self.cur_site = site
 
-    def get_cur_ydl(self) -> YoutubeDL:
+        for param in self.updated_params:
-
+            del self.ydl.params[param]
-        ydl = self.cur_ydl
+        self.updated_params.clear()
-        if ydl is None:
+        self.need_process = False
-            raise RuntimeError('ydl object not initialized')
-        return ydl
 
     async def get_playlist_items(self, url: str) -> list[str]:
 
         return await asyncio.get_event_loop().run_in_executor(
             None,
             Downloader._target_get_playlist_items,
-            self.get_cur_ydl(),
+            self.ydl,
             url,
-            self.cur_site in NP_YDLS,
+            self.need_process,
         )
 
     @staticmethod
     def _target_get_playlist_items(ydl: YoutubeDL, url: str, process: bool) -> list[str]:
 
         info = ydl.extract_info(url, download=False, process=process)
+
         if info is None:
             raise RuntimeError('ydl.extract_info returned None')
+
         return [
             entry['track'] if 'track' in entry else entry['title']
             for entry in info['entries']
         ]
 
-    async def download(
+    async def download(self, url: str) -> int:
-            self,
-            url: str,
-            playlist_items: Iterable[int] | None = None) -> int:
 
         return await asyncio.get_event_loop().run_in_executor(
             None,
             Downloader._target_download,
-            self.get_cur_ydl(),
+            self.ydl,
             url,
-            playlist_items,
         )
 
     @staticmethod
-    def _target_download(
+    def _target_download(ydl: YoutubeDL, url: str) -> int:
-            ydl: YoutubeDL,
-            url: str,
-            playlist_items: Iterable[int] | None = None) -> int:
 
-        if playlist_items:
+        return ydl.download(url)
-            ydl.params['playlist_items'] = ','.join(str(i) for i in playlist_items)
-
-        ret = ydl.download(url)
-
-        if playlist_items:
-            del ydl.params['playlist_items']
-
-        return ret
 
     def cleanup(self) -> None:
 
-        for ydl in self.ydls.values():
+        self.ydl.close()
-            if ydl is not None:
-                ydl.close()