refactor: add is_available method to fetchers

lrcfetch/core.py

@@ -51,18 +51,9 @@ class LrcManager:
             return [self.fetchers[force_method]]
 
         sequence: list[BaseFetcher] = []
-        if track.is_local:
-            sequence.append(self.fetchers["local"])
-        if track.title:
-            sequence.append(self.fetchers["cache-search"])
-        if track.trackid:
-            sequence.append(self.fetchers["spotify"])
-        if track.is_complete:
-            sequence.append(self.fetchers["lrclib"])
-        if track.title:
-            sequence.append(self.fetchers["lrclib-search"])
-        sequence.append(self.fetchers["netease"])
-        sequence.append(self.fetchers["qqmusic"])
+        for method in self.fetchers.keys():
+            if self.fetchers[method].is_available(track):
+                sequence.append(self.fetchers[method])
 
         logger.debug(f"Fallback sequence: {[f.source_name for f in sequence]}")
         return sequence

lrcfetch/fetchers/base.py

@@ -22,6 +22,11 @@ class BaseFetcher(ABC):
         """True if this fetcher manages its own cache (skip per-source cache check)."""
         return False
 
+    @abstractmethod
+    def is_available(self, track: TrackMeta) -> bool:
+        """Check if the fetcher is available for the given track (e.g. has required metadata)."""
+        pass
+
     @abstractmethod
     def fetch(
         self, track: TrackMeta, bypass_cache: bool = False

lrcfetch/fetchers/cache_search.py

@@ -30,6 +30,9 @@ class CacheSearchFetcher(BaseFetcher):
     def self_cached(self) -> bool:
         return True
 
+    def is_available(self, track: TrackMeta) -> bool:
+        return bool(track.title)
+
     def fetch(
         self, track: TrackMeta, bypass_cache: bool = False
     ) -> Optional[LyricResult]:

lrcfetch/fetchers/local.py

@@ -25,6 +25,9 @@ class LocalFetcher(BaseFetcher):
     def source_name(self) -> str:
         return "local"
 
+    def is_available(self, track: TrackMeta) -> bool:
+        return track.is_local
+
     def fetch(
         self, track: TrackMeta, bypass_cache: bool = False
     ) -> Optional[LyricResult]:

lrcfetch/fetchers/lrclib.py

@@ -31,6 +31,9 @@ class LrclibFetcher(BaseFetcher):
     def source_name(self) -> str:
         return "lrclib"
 
+    def is_available(self, track: TrackMeta) -> bool:
+        return track.is_complete
+
     def fetch(
         self, track: TrackMeta, bypass_cache: bool = False
     ) -> Optional[LyricResult]:

lrcfetch/fetchers/lrclib_search.py

@@ -33,6 +33,9 @@ class LrclibSearchFetcher(BaseFetcher):
     def source_name(self) -> str:
         return "lrclib-search"
 
+    def is_available(self, track: TrackMeta) -> bool:
+        return bool(track.title)
+
     def fetch(
         self, track: TrackMeta, bypass_cache: bool = False
     ) -> Optional[LyricResult]:

lrcfetch/fetchers/netease.py

@@ -40,6 +40,9 @@ class NeteaseFetcher(BaseFetcher):
     def source_name(self) -> str:
         return "netease"
 
+    def is_available(self, track: TrackMeta) -> bool:
+        return bool(track.title)
+
     def _search(self, track: TrackMeta, limit: int = 10) -> Optional[int]:
         """Search Netease and return the best-matching song ID.
 

lrcfetch/fetchers/qqmusic.py

@@ -32,6 +32,9 @@ class QQMusicFetcher(BaseFetcher):
     def source_name(self) -> str:
         return "qqmusic"
 
+    def is_available(self, track: TrackMeta) -> bool:
+        return bool(track.title) and bool(QQ_MUSIC_API_URL)
+
     def _search(self, track: TrackMeta, limit: int = 10) -> Optional[str]:
         """Search QQ Music and return the best-matching song MID."""
         query = f"{track.artist or ''} {track.title or ''}".strip()

lrcfetch/fetchers/spotify.py

@@ -55,6 +55,9 @@ class SpotifyFetcher(BaseFetcher):
     def source_name(self) -> str:
         return "spotify"
 
+    def is_available(self, track: TrackMeta) -> bool:
+        return bool(track.trackid) and bool(SPOTIFY_SP_DC)
+
     # ─── Auth helpers ────────────────────────────────────────────────
 
     def _get_server_time(self, client: httpx.Client) -> Optional[int]: