Improve offline support for Compilations

ultrasonic/src/main/kotlin/org/moire/ultrasonic/data/AlbumDao.kt

@@ -19,6 +19,12 @@ interface AlbumDao : GenericDao<Album> {
     @Query("SELECT * FROM albums")
     fun get(): List<Album>
 
+    /**
+     * Get album by id
+     */
+    @Query("SELECT * FROM albums where id LIKE :albumId LIMIT 1")
+    fun get(albumId: String): Album
+
     /**
      * Get albums by artist
      */

ultrasonic/src/main/kotlin/org/moire/ultrasonic/data/TrackDao.kt

@@ -25,4 +25,10 @@ interface TrackDao : GenericDao<Track> {
      */
     @Query("SELECT * FROM tracks WHERE albumId LIKE :id")
     fun byAlbum(id: String): List<Track>
+
+    /**
+     * Get albums by artist
+     */
+    @Query("SELECT * FROM tracks WHERE artistId LIKE :id")
+    fun byArtist(id: String): List<Track>
 }

ultrasonic/src/main/kotlin/org/moire/ultrasonic/service/Downloader.kt

@@ -14,6 +14,7 @@ import java.util.PriorityQueue
 import org.koin.core.component.KoinComponent
 import org.koin.core.component.inject
 import org.moire.ultrasonic.data.ActiveServerProvider
+import org.moire.ultrasonic.data.MetaDatabase
 import org.moire.ultrasonic.domain.Artist
 import org.moire.ultrasonic.domain.Track
 import org.moire.ultrasonic.playback.LegacyPlaylistManager
@@ -402,6 +403,14 @@ class Downloader(
                             downloadFile.completeFile
                         )
                     }
+
+                    // Hidden feature: If track is toggled between pinned/saved, refresh the metadata..
+                    try {
+                        downloadFile.track.cacheMetadata()
+                    } catch (ignore: Exception) {
+                        Timber.w(ignore)
+                    }
+
                     downloadFile.status.postValue(newStatus)
                     return
                 }
@@ -518,7 +527,29 @@ class Downloader(
             val onlineDB = activeServerProvider.getActiveMetaDatabase()
             val offlineDB = activeServerProvider.offlineMetaDatabase
 
-            var artist: Artist? = onlineDB.artistDao().get(artistId!!)
+            cacheArtist(onlineDB, offlineDB, artistId!!)
+
+            // Now cache the album
+            if (albumId?.isNotEmpty() == true) {
+                // This is a cached call
+                val albums = musicService.getAlbumsOfArtist(artistId!!, null, false)
+                val album = albums.find { it.id == albumId }
+
+                if (album != null) {
+                    offlineDB.albumDao().insert(album)
+
+                    // If the album is a Compilation, also cache the Album artist
+                    if (album.artistId != null && album.artistId != artistId)
+                        cacheArtist(onlineDB, offlineDB, album.artistId!!)
+                }
+            }
+
+            // Now cache the track data
+            offlineDB.trackDao().insert(this)
+        }
+
+        private fun cacheArtist(onlineDB: MetaDatabase, offlineDB: MetaDatabase, artistId: String) {
+            var artist: Artist? = onlineDB.artistDao().get(artistId)
 
             // If we are downloading a new album, and the user has not visited the Artists list
             // recently, then the artist won't be in the database.
@@ -533,20 +564,6 @@ class Downloader(
             if (artist != null) {
                 offlineDB.artistDao().insert(artist)
             }
-
-            // Now cache the album
-            if (albumId?.isNotEmpty() == true) {
-                // This is a cached call
-                val albums = musicService.getAlbumsOfArtist(artistId!!, null, false)
-                val album = albums.find { it.id == albumId }
-
-                if (album != null) {
-                    offlineDB.albumDao().insert(album)
-                }
-            }
-
-            // Now cache the track data
-            offlineDB.trackDao().insert(this)
         }
 
         private fun downloadAndSaveCoverArt() {

ultrasonic/src/main/kotlin/org/moire/ultrasonic/service/OfflineMusicService.kt

@@ -110,9 +110,6 @@ class OfflineMusicService : MusicService, KoinComponent {
     override fun getArtists(refresh: Boolean): List<Artist> {
         val result = cachedArtists.get()
 
-        if (result.isEmpty()) {
-            // use indexes?
-        }
         return result
     }
 
@@ -472,7 +469,20 @@ class OfflineMusicService : MusicService, KoinComponent {
     @Throws(Exception::class)
     override fun getAlbumsOfArtist(id: String, name: String?, refresh: Boolean):
         List<Album> {
-        return cachedAlbums.byArtist(id)
+        val directAlbums = cachedAlbums.byArtist(id)
+
+        // The direct albums won't contain any compilations that the artist has participated in
+        // We need to fetch the tracks of the artist and then gather the compilation albums from that.
+        val tracks = cachedTracks.byArtist(id)
+        val albumIds = tracks.map {
+            it.albumId
+        }.distinct().filterNotNull()
+
+        val compilationAlbums = albumIds.map {
+            cachedAlbums.get(it)
+        }
+
+        return directAlbums.plus(compilationAlbums).distinct()
     }
 
     @Throws(OfflineException::class)