Added the playlist generator

shanty-data/src/traits.rs

@@ -2,8 +2,8 @@ use std::future::Future;
 
 use crate::error::DataResult;
 use crate::types::{
-    ArtistInfo, ArtistSearchResult, DiscographyEntry, LyricsResult, RecordingDetails,
-    RecordingMatch, ReleaseGroupEntry, ReleaseMatch, ReleaseTrack,
+    ArtistInfo, ArtistSearchResult, DiscographyEntry, LyricsResult, PopularTrack, RecordingDetails,
+    RecordingMatch, ReleaseGroupEntry, ReleaseMatch, ReleaseTrack, SimilarArtist,
 };
 
 /// Trait for metadata lookup backends. MusicBrainz is the default implementation;
@@ -86,6 +86,21 @@ pub trait LyricsFetcher: Send + Sync {
     ) -> impl Future<Output = DataResult<LyricsResult>> + Send;
 }
 
+/// Fetches similar artists and top tracks from an external source (e.g. Last.fm).
+pub trait SimilarArtistFetcher: Send + Sync {
+    fn get_similar_artists(
+        &self,
+        artist_name: &str,
+        mbid: Option<&str>,
+    ) -> impl Future<Output = DataResult<Vec<SimilarArtist>>> + Send;
+
+    fn get_top_tracks(
+        &self,
+        artist_name: &str,
+        mbid: Option<&str>,
+    ) -> impl Future<Output = DataResult<Vec<PopularTrack>>> + Send;
+}
+
 /// Fetches cover art URLs for releases.
 pub trait CoverArtFetcher: Send + Sync {
     fn get_cover_art_url(&self, release_id: &str) -> Option<String>;