src/tui/app/machine/fetch_state.rs

@@ -16,7 +16,7 @@ use crate::tui::{
         AppPublicState, AppState, Category, IAppEventFetch, IAppInteractFetch,
     },
     lib::interface::musicbrainz::daemon::{
-        Error as DaemonError, IMbJobSender, MbApiResult, MbParams, ResultSender,
+        Error as DaemonError, IMbJobSender, MbApiResult, MbParams, MbReturn, ResultSender,
     },
 };
 
@@ -116,9 +116,7 @@ impl AppMachine<FetchState> {
     pub fn app_fetch_next(inner: AppInner, mut fetch: FetchState) -> App {
         match fetch.try_recv() {
             Ok(fetch_result) => match fetch_result {
-                Ok(next_match) => {
-                    AppMachine::match_state(inner, MatchState::new(next_match, fetch)).into()
-                }
+                Ok(retval) => Self::handle_mb_api_return(inner, fetch, retval),
                 Err(fetch_err) => {
                     AppMachine::error_state(inner, format!("fetch failed: {fetch_err}")).into()
                 }
@@ -130,6 +128,15 @@ impl AppMachine<FetchState> {
         }
     }
 
+    fn handle_mb_api_return(inner: AppInner, fetch: FetchState, retval: MbReturn) -> App {
+        match retval {
+            MbReturn::Match(next_match) => {
+                AppMachine::match_state(inner, MatchState::new(next_match, fetch)).into()
+            }
+            _ => unimplemented!(),
+        }
+    }
+
     pub fn app_lookup_artist(
         inner: AppInner,
         fetch: FetchState,
@@ -311,13 +318,13 @@ mod tests {
         let artist = COLLECTION[3].meta.clone();
 
         let matches: Vec<Entity<ArtistMeta>> = vec![];
-        let fetch_result = EntityMatches::artist_search(artist.clone(), matches);
+        let fetch_result = MbReturn::Match(EntityMatches::artist_search(artist.clone(), matches));
         fetch_tx.send(Ok(fetch_result.clone())).unwrap();
 
         assert_eq!(fetch.try_recv(), Err(TryRecvError::Empty));
 
         let lookup = Entity::new(artist.clone());
-        let lookup_result = EntityMatches::artist_lookup(artist.clone(), lookup);
+        let lookup_result = MbReturn::Match(EntityMatches::artist_lookup(artist.clone(), lookup));
         lookup_tx.send(Ok(lookup_result.clone())).unwrap();
 
         assert_eq!(fetch.try_recv(), Ok(Ok(lookup_result)));
@@ -604,7 +611,7 @@ mod tests {
         let artist_match = Entity::with_score(COLLECTION[2].meta.clone(), 80);
         let artist_match_info =
             EntityMatches::artist_search(artist.clone(), vec![artist_match.clone()]);
-        let fetch_result = Ok(artist_match_info);
+        let fetch_result = Ok(MbReturn::Match(artist_match_info));
         tx.send(fetch_result).unwrap();
 
         let inner = inner(music_hoard(COLLECTION.clone()));
@@ -678,7 +685,7 @@ mod tests {
 
         let artist = COLLECTION[3].meta.clone();
         let match_info = EntityMatches::artist_search::<Entity<ArtistMeta>>(artist, vec![]);
-        let fetch_result = Ok(match_info);
+        let fetch_result = Ok(MbReturn::Match(match_info));
         tx.send(fetch_result).unwrap();
 
         let app = app.unwrap_fetch().fetch_result_ready();

src/tui/lib/external/musicbrainz/daemon/mod.rs

@@ -5,7 +5,9 @@ use crate::tui::{
     event::IFetchCompleteEventSender,
     lib::interface::musicbrainz::{
         api::{Error as ApiError, IMusicBrainz},
-        daemon::{Error, IMbJobSender, LookupParams, MbParams, ResultSender, SearchParams},
+        daemon::{
+            Error, IMbJobSender, LookupParams, MbParams, MbReturn, ResultSender, SearchParams,
+        },
     },
 };
 
@@ -256,13 +258,13 @@ impl JobInstance {
                     .map(|rv| EntityMatches::album_search(params.artist_id, params.album, rv)),
             },
         };
-        self.return_result(event_sender, result)
+        self.return_result(event_sender, result.map(MbReturn::Match))
     }
 
     fn return_result(
         &mut self,
         event_sender: &mut dyn IFetchCompleteEventSender,
-        result: Result<EntityMatches, ApiError>,
+        result: Result<MbReturn, ApiError>,
     ) -> Result<(), JobInstanceError> {
         self.result_sender
             .send(result)
@@ -575,7 +577,12 @@ mod tests {
         assert_eq!(result, Ok(()));
 
         let result = result_receiver.try_recv().unwrap();
-        assert_eq!(result, Ok(EntityMatches::artist_lookup(artist, lookup)));
+        assert_eq!(
+            result,
+            Ok(MbReturn::Match(EntityMatches::artist_lookup(
+                artist, lookup
+            )))
+        );
     }
 
     fn lookup_release_group_expectation(
@@ -620,7 +627,9 @@ mod tests {
         let artist_id = album_artist_id();
         assert_eq!(
             result,
-            Ok(EntityMatches::album_lookup(artist_id, album, lookup))
+            Ok(MbReturn::Match(EntityMatches::album_lookup(
+                artist_id, album, lookup
+            )))
         );
     }
 
@@ -661,7 +670,12 @@ mod tests {
         assert_eq!(result, Ok(()));
 
         let result = result_receiver.try_recv().unwrap();
-        assert_eq!(result, Ok(EntityMatches::artist_search(artist, matches)));
+        assert_eq!(
+            result,
+            Ok(MbReturn::Match(EntityMatches::artist_search(
+                artist, matches
+            )))
+        );
     }
 
     fn search_release_group_expectation(
@@ -716,21 +730,21 @@ mod tests {
         let result = result_receiver.try_recv().unwrap();
         assert_eq!(
             result,
-            Ok(EntityMatches::album_search(
+            Ok(MbReturn::Match(EntityMatches::album_search(
                 artist_id.clone(),
                 album_1,
                 matches_1
-            ))
+            )))
         );
 
         let result = result_receiver.try_recv().unwrap();
         assert_eq!(
             result,
-            Ok(EntityMatches::album_search(
+            Ok(MbReturn::Match(EntityMatches::album_search(
                 artist_id.clone(),
                 album_4,
                 matches_4
-            ))
+            )))
         );
     }
 

src/tui/lib/interface/musicbrainz/daemon/mod.rs

@@ -26,9 +26,21 @@ impl fmt::Display for Error {
     }
 }
 
-pub type MbApiResult = Result<EntityMatches, MbApiError>;
+pub type MbApiResult = Result<MbReturn, MbApiError>;
 pub type ResultSender = mpsc::Sender<MbApiResult>;
 
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub enum MbReturn {
+    Match(EntityMatches),
+    Fetch(EntityList),
+}
+
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub enum EntityList {
+    Artist(Vec<ArtistMeta>),
+    Album(Vec<AlbumMeta>),
+}
+
 #[cfg_attr(test, automock)]
 pub trait IMbJobSender {
     fn submit_foreground_job(