Some code cleanup

src/lastfm.rs

@@ -98,6 +98,37 @@ impl LastfmClient {
         Ok(None)
     }
 
+    /// Try MBID lookup then name lookup, returning whichever yields more results.
+    #[allow(clippy::type_complexity)]
+    fn dual_lookup<T>(
+        &self,
+        method: &str,
+        artist_mbid: &str,
+        artist_name: Option<&str>,
+        extra_params: &str,
+        parse: fn(&str) -> Result<Vec<T>, Box<dyn std::error::Error>>,
+    ) -> Result<Vec<T>, Box<dyn std::error::Error>> {
+        let mbid_url = format!(
+            "{}?method={}&mbid={}&api_key={}{}&format=json",
+            BASE_URL, method, artist_mbid, self.api_key, extra_params
+        );
+        let mbid_results = match self.fetch_or_none(&mbid_url)? {
+            Some(body) => parse(&body).unwrap_or_default(),
+            None => Vec::new(),
+        };
+
+        let name_results = match self.fetch_by_name(method, artist_name, extra_params)? {
+            Some(body) => parse(&body).unwrap_or_default(),
+            None => Vec::new(),
+        };
+
+        if name_results.len() > mbid_results.len() {
+            Ok(name_results)
+        } else {
+            Ok(mbid_results)
+        }
+    }
+
     fn parse_similar_artists(body: &str) -> Result<Vec<SimilarArtist>, Box<dyn std::error::Error>> {
         let resp: SimilarArtistsResponse = serde_json::from_str(body)?;
         Ok(resp
@@ -120,30 +151,13 @@ impl LastfmClient {
         artist_mbid: &str,
         artist_name: Option<&str>,
     ) -> Result<Vec<SimilarArtist>, Box<dyn std::error::Error>> {
-        let method = "artist.getSimilar";
-        let extra = "&limit=500";
-
-        // Try MBID lookup
-        let mbid_url = format!(
-            "{}?method={}&mbid={}&api_key={}{}&format=json",
-            BASE_URL, method, artist_mbid, self.api_key, extra
-        );
-        let mbid_results = match self.fetch_or_none(&mbid_url)? {
-            Some(body) => Self::parse_similar_artists(&body).unwrap_or_default(),
-            None => Vec::new(),
-        };
-
-        // Try name lookup and return whichever has more results
-        let name_results = match self.fetch_by_name(method, artist_name, extra)? {
-            Some(body) => Self::parse_similar_artists(&body).unwrap_or_default(),
-            None => Vec::new(),
-        };
-
-        if name_results.len() > mbid_results.len() {
-            Ok(name_results)
-        } else {
-            Ok(mbid_results)
-        }
+        self.dual_lookup(
+            "artist.getSimilar",
+            artist_mbid,
+            artist_name,
+            "&limit=500",
+            Self::parse_similar_artists,
+        )
     }
 
     fn parse_top_tracks(body: &str) -> Result<Vec<TopTrack>, Box<dyn std::error::Error>> {
@@ -165,29 +179,12 @@ impl LastfmClient {
         artist_mbid: &str,
         artist_name: Option<&str>,
     ) -> Result<Vec<TopTrack>, Box<dyn std::error::Error>> {
-        let method = "artist.getTopTracks";
-        let extra = "&limit=1000";
-
-        // Try MBID lookup
-        let mbid_url = format!(
-            "{}?method={}&mbid={}&api_key={}{}&format=json",
-            BASE_URL, method, artist_mbid, self.api_key, extra
-        );
-        let mbid_results = match self.fetch_or_none(&mbid_url)? {
-            Some(body) => Self::parse_top_tracks(&body).unwrap_or_default(),
-            None => Vec::new(),
-        };
-
-        // Try name lookup and return whichever has more results
-        let name_results = match self.fetch_by_name(method, artist_name, extra)? {
-            Some(body) => Self::parse_top_tracks(&body).unwrap_or_default(),
-            None => Vec::new(),
-        };
-
-        if name_results.len() > mbid_results.len() {
-            Ok(name_results)
-        } else {
-            Ok(mbid_results)
-        }
+        self.dual_lookup(
+            "artist.getTopTracks",
+            artist_mbid,
+            artist_name,
+            "&limit=1000",
+            Self::parse_top_tracks,
+        )
     }
 }