Hardened the lookups

src/lastfm.rs

@@ -70,20 +70,59 @@ impl LastfmClient {
         Self { api_key }
     }
 
+    /// Fetch a URL and return the body. Returns `None` if Last.fm returns an API error.
+    fn fetch_or_none(&self, url: &str) -> Result<Option<String>, Box<dyn std::error::Error>> {
+        let body: String = ureq::get(url).call()?.body_mut().read_to_string()?;
+        if serde_json::from_str::<ApiError>(&body).is_ok() {
+            return Ok(None);
+        }
+        Ok(Some(body))
+    }
+
+    /// Try fetching by MBID first, fall back to artist name.
+    fn fetch_with_fallback(
+        &self,
+        method: &str,
+        artist_mbid: &str,
+        artist_name: Option<&str>,
+        extra_params: &str,
+    ) -> Result<Option<String>, Box<dyn std::error::Error>> {
+        let url = format!(
+            "{}?method={}&mbid={}&api_key={}{}&format=json",
+            BASE_URL, method, artist_mbid, self.api_key, extra_params
+        );
+        if let Some(body) = self.fetch_or_none(&url)? {
+            return Ok(Some(body));
+        }
+
+        // Fall back to artist name
+        if let Some(name) = artist_name {
+            let encoded = urlencoding::encode(name);
+            let url = format!(
+                "{}?method={}&artist={}&api_key={}{}&format=json",
+                BASE_URL, method, encoded, self.api_key, extra_params
+            );
+            if let Some(body) = self.fetch_or_none(&url)? {
+                return Ok(Some(body));
+            }
+        }
+
+        Ok(None)
+    }
+
     pub fn get_similar_artists(
         &self,
         artist_mbid: &str,
+        artist_name: Option<&str>,
     ) -> Result<Vec<SimilarArtist>, Box<dyn std::error::Error>> {
-        let url = format!(
-            "{}?method=artist.getSimilar&mbid={}&api_key={}&limit=500&format=json",
-            BASE_URL, artist_mbid, self.api_key
-        );
-        let body: String = ureq::get(&url).call()?.body_mut().read_to_string()?;
-
-        if let Ok(err) = serde_json::from_str::<ApiError>(&body) {
-            eprintln!("  Last.fm: {}", err.message);
+        let Some(body) = self.fetch_with_fallback(
+            "artist.getSimilar",
+            artist_mbid,
+            artist_name,
+            "&limit=500",
+        )? else {
             return Ok(Vec::new());
-        }
+        };
 
         let resp: SimilarArtistsResponse = serde_json::from_str(&body)?;
         Ok(resp
@@ -104,17 +143,16 @@ impl LastfmClient {
     pub fn get_top_tracks(
         &self,
         artist_mbid: &str,
+        artist_name: Option<&str>,
     ) -> Result<Vec<TopTrack>, Box<dyn std::error::Error>> {
-        let url = format!(
-            "{}?method=artist.getTopTracks&mbid={}&api_key={}&limit=1000&format=json",
-            BASE_URL, artist_mbid, self.api_key
-        );
-        let body: String = ureq::get(&url).call()?.body_mut().read_to_string()?;
-
-        if let Ok(err) = serde_json::from_str::<ApiError>(&body) {
-            eprintln!("  Last.fm: {}", err.message);
+        let Some(body) = self.fetch_with_fallback(
+            "artist.getTopTracks",
+            artist_mbid,
+            artist_name,
+            "&limit=1000",
+        )? else {
             return Ok(Vec::new());
-        }
+        };
 
         let resp: TopTracksResponse = serde_json::from_str(&body)?;
         Ok(resp