examples/musicbrainz_api/browse.rs

@@ -72,7 +72,7 @@ fn main() {
                     println!("Release groups in this response: {count}");
 
                     match response.page.next_page_offset(count) {
-                        NextPage::Offset(next_offset) => paging.with_offset(next_offset),
+                        NextPage::Offset(next_offset) => paging.set_offset(next_offset),
                         NextPage::Complete => break,
                     }
 

src/external/musicbrainz/api/mod.rs

@@ -61,7 +61,7 @@ impl<Http> MusicBrainzClient<Http> {
     }
 }
 
-#[derive(Default)]
+#[derive(Debug, Default)]
 pub struct PageSettings {
     limit: Option<usize>,
     offset: Option<usize>,
@@ -79,7 +79,12 @@ impl PageSettings {
         Self::with_limit(MB_MAX_PAGE_LIMIT)
     }
 
-    pub fn with_offset(&mut self, offset: usize) {
+    pub fn with_offset(mut self, offset: usize) -> Self {
+        self.offset = Some(offset);
+        self
+    }
+
+    pub fn set_offset(&mut self, offset: usize) {
         self.offset = Some(offset);
     }
 }
@@ -91,6 +96,10 @@ pub enum NextPage {
 }
 
 impl NextPage {
+    pub fn new() -> NextPage {
+        NextPage::Offset(0)
+    }
+
     pub fn next_page_offset(offset: usize, total_count: usize, page_count: usize) -> NextPage {
         let next_offset = offset + page_count;
         if next_offset < total_count {
@@ -387,14 +396,14 @@ mod tests {
         assert_eq!(ApiDisplay::format_page_settings(&paging), "&limit=100");
 
         let mut paging = PageSettings::with_limit(45);
-        paging.with_offset(145);
+        paging.set_offset(145);
         assert_eq!(
             ApiDisplay::format_page_settings(&paging),
             "&limit=45&offset=145"
         );
 
         let mut paging = PageSettings::default();
-        paging.with_offset(26);
+        paging.set_offset(26);
         assert_eq!(ApiDisplay::format_page_settings(&paging), "&offset=26");
     }
 

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

@@ -1,12 +1,15 @@
 use std::{collections::VecDeque, sync::mpsc, thread, time};
 
+use musichoard::external::musicbrainz::api::{NextPage, PageSettings};
+
 use crate::tui::{
     app::EntityMatches,
     event::IFetchCompleteEventSender,
     lib::interface::musicbrainz::{
-        api::{Error as ApiError, IMusicBrainz},
+        api::{Error as ApiError, IMusicBrainz, Paged},
         daemon::{
-            Error, IMbJobSender, LookupParams, MbParams, MbReturn, ResultSender, SearchParams,
+            BrowseParams, EntityList, Error, IMbJobSender, LookupParams, MbParams, MbReturn,
+            ResultSender, SearchParams,
         },
     },
 };
@@ -45,6 +48,7 @@ enum JobPriority {
 struct JobInstance {
     result_sender: ResultSender,
     requests: VecDeque<MbParams>,
+    paging: Option<PageSettings>,
 }
 
 #[derive(Debug, PartialEq, Eq)]
@@ -64,6 +68,7 @@ impl JobInstance {
         JobInstance {
             result_sender,
             requests,
+            paging: None,
         }
     }
 }
@@ -223,8 +228,17 @@ impl JobInstance {
         event_sender: &mut dyn IFetchCompleteEventSender,
     ) -> Result<JobInstanceStatus, JobInstanceError> {
         // self.requests can be empty if the caller submits an empty job.
-        if let Some(params) = self.requests.pop_front() {
-            self.execute(musicbrainz, event_sender, params)?
+        self.paging = match self.requests.front() {
+            Some(params) => {
+                let result_sender = &mut self.result_sender;
+                let paging = self.paging.take();
+                Self::execute(musicbrainz, result_sender, event_sender, &params, paging)?
+            }
+            None => None,
+        };
+
+        if self.paging.is_none() {
+            self.requests.pop_front();
         }
 
         if self.requests.is_empty() {
@@ -235,38 +249,64 @@ impl JobInstance {
     }
 
     fn execute(
-        &mut self,
         musicbrainz: &mut dyn IMusicBrainz,
+        result_sender: &mut ResultSender,
         event_sender: &mut dyn IFetchCompleteEventSender,
-        api_params: MbParams,
-    ) -> Result<(), JobInstanceError> {
+        api_params: &MbParams,
+        paging: Option<PageSettings>,
+    ) -> Result<Option<PageSettings>, JobInstanceError> {
+        let mut paging = match paging {
+            Some(paging) => paging,
+            None => PageSettings::with_max_limit(),
+        };
+        let mut next_page = NextPage::Complete;
+
         let result = match api_params {
             MbParams::Lookup(lookup) => match lookup {
-                LookupParams::Artist(params) => musicbrainz
-                    .lookup_artist(&params.mbid)
-                    .map(|rv| EntityMatches::artist_lookup(params.artist, rv)),
-                LookupParams::ReleaseGroup(params) => musicbrainz
-                    .lookup_release_group(&params.mbid)
-                    .map(|rv| EntityMatches::album_lookup(params.artist_id, params.album, rv)),
-            },
+                LookupParams::Artist(p) => musicbrainz
+                    .lookup_artist(&p.mbid)
+                    .map(|rv| EntityMatches::artist_lookup(p.artist.clone(), rv)),
+                LookupParams::ReleaseGroup(p) => {
+                    musicbrainz.lookup_release_group(&p.mbid).map(|rv| {
+                        EntityMatches::album_lookup(p.artist_id.clone(), p.album.clone(), rv)
+                    })
+                }
+            }
+            .map(MbReturn::Match),
             MbParams::Search(search) => match search {
-                SearchParams::Artist(params) => musicbrainz
-                    .search_artist(&params.artist)
-                    .map(|rv| EntityMatches::artist_search(params.artist, rv)),
-                SearchParams::ReleaseGroup(params) => musicbrainz
-                    .search_release_group(&params.artist_mbid, &params.album)
-                    .map(|rv| EntityMatches::album_search(params.artist_id, params.album, rv)),
-            },
+                SearchParams::Artist(p) => musicbrainz
+                    .search_artist(&p.artist)
+                    .map(|rv| EntityMatches::artist_search(p.artist.clone(), rv)),
+                SearchParams::ReleaseGroup(p) => musicbrainz
+                    .search_release_group(&p.artist_mbid, &p.album)
+                    .map(|rv| {
+                        EntityMatches::album_search(p.artist_id.clone(), p.album.clone(), rv)
+                    }),
+            }
+            .map(MbReturn::Match),
+            MbParams::Browse(browse) => match browse {
+                BrowseParams::ReleaseGroup(params) => Paged::map_paged_result(
+                    musicbrainz.browse_release_group(&params.artist, &mut paging),
+                    |ents| EntityList::Album(ents.into_iter().map(|rg| rg.entity).collect()),
+                    &mut next_page,
+                ),
+            }
+            .map(MbReturn::Fetch),
         };
-        self.return_result(event_sender, result.map(MbReturn::Match))
+        Self::return_result(result_sender, event_sender, result)?;
+
+        Ok(match next_page {
+            NextPage::Offset(offset) => Some(paging.with_offset(offset)),
+            NextPage::Complete => None,
+        })
     }
 
     fn return_result(
-        &mut self,
+        result_sender: &mut ResultSender,
         event_sender: &mut dyn IFetchCompleteEventSender,
         result: Result<MbReturn, ApiError>,
     ) -> Result<(), JobInstanceError> {
-        self.result_sender
+        result_sender
             .send(result)
             .map_err(|_| JobInstanceError::ReturnChannelDisconnected)?;
 

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

@@ -1,5 +1,7 @@
 //! Module for accessing MusicBrainz metadata.
 
+use std::mem;
+
 #[cfg(test)]
 use mockall::automock;
 
@@ -47,4 +49,26 @@ pub struct Paged<T> {
     pub next: NextPage,
 }
 
+// pub fn map<U, F: FnOnce(T) -> U>(self, op: F) -> Result<U, E> {
+//     match self {
+//         Ok(t) => Ok(op(t)),
+//         Err(e) => Err(e),
+//     }
+// }
+
+impl<T> Paged<T> {
+    pub fn map_paged_result<E, U, F: FnOnce(T) -> U>(
+        result: Result<Paged<T>, E>,
+        op: F,
+        next: &mut NextPage,
+    ) -> Result<U, E> {
+        match result {
+            Ok(paged) => {
+                _ = mem::replace(next, paged.next);
+                Ok(op(paged.item))
+            }
+            Err(err) => Err(err),
+        }
+    }
+}
 pub type Error = musichoard::external::musicbrainz::api::Error;

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

@@ -37,7 +37,6 @@ pub enum MbReturn {
 
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub enum EntityList {
-    Artist(Vec<ArtistMeta>),
     Album(Vec<AlbumMeta>),
 }
 
@@ -60,6 +59,7 @@ pub trait IMbJobSender {
 pub enum MbParams {
     Lookup(LookupParams),
     Search(SearchParams),
+    Browse(BrowseParams),
 }
 
 #[derive(Clone, Debug, PartialEq, Eq)]
@@ -99,6 +99,16 @@ pub struct SearchReleaseGroupParams {
     pub album: AlbumMeta,
 }
 
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub enum BrowseParams {
+    ReleaseGroup(BrowseReleaseGroupParams),
+}
+
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct BrowseReleaseGroupParams {
+    pub artist: Mbid,
+}
+
 impl MbParams {
     pub fn lookup_artist(artist: ArtistMeta, mbid: Mbid) -> Self {
         MbParams::Lookup(LookupParams::Artist(LookupArtistParams { artist, mbid }))