updated to use domain layer in a smart way

app/src/main/java/com/stephenbain/pagingsamples/data/datasource/PlaylistsBoundaryCallback.kt

@@ -1,7 +1,6 @@
 package com.stephenbain.pagingsamples.data.datasource
 
-import com.stephenbain.pagingsamples.data.db.PlaylistDao
-import com.stephenbain.pagingsamples.data.domain.GetMyPlaylists
+import com.stephenbain.pagingsamples.data.domain.UpdatePlaylists
 import com.stephenbain.pagingsamples.data.model.Playlist
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.delay
@@ -11,19 +10,16 @@ import timber.log.Timber
 class PlaylistsBoundaryCallback(
     private val pageSize: Int,
     scope: CoroutineScope,
-    private val playlistDao: PlaylistDao,
-    private val getMyPlaylists: GetMyPlaylists
+    private val updatePlaylists: UpdatePlaylists
 ) : PositionalBoundaryCallback<Playlist>(pageSize, scope) {
 
     override suspend fun initialLoad() {
-        val paging = getMyPlaylists(limit = pageSize)
-        playlistDao.insertAll(paging.items)
+        updatePlaylists(limit = pageSize)
     }
 
     override suspend fun itemAtEndLoad(offset: Int) {
         try {
-            val paging = getMyPlaylists(limit = pageSize, offset = playlistDao.getItemCount())
-            playlistDao.insertAll(paging.items)
+            updatePlaylists(limit = pageSize)
         } catch (t: Throwable) {
             Timber.e(t, "error getting playlists")
             // hack around rate limiting. delay by 200 and retry

app/src/main/java/com/stephenbain/pagingsamples/data/domain/UpdatePlaylists.kt

@@ -0,0 +1,28 @@
+package com.stephenbain.pagingsamples.data.domain
+
+import com.stephenbain.pagingsamples.data.db.PlaylistDao
+import com.stephenbain.pagingsamples.data.repo.TokenRepository
+import com.stephenbain.pagingsamples.data.retrofit.SpotifyService
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+import javax.inject.Inject
+
+
+class UpdatePlaylists @Inject constructor(
+    private val spotifyService: SpotifyService,
+    private val playlistDao: PlaylistDao,
+    private val tokenRepository: TokenRepository
+) {
+
+    suspend operator fun invoke(limit: Int) {
+        withContext(Dispatchers.IO) {
+            val paging = spotifyService.getMyPlaylists(
+                token = "Bearer ${tokenRepository.token}",
+                offset = playlistDao.getItemCount(),
+                limit = limit
+            ).await()
+            playlistDao.insertAll(paging.items)
+        }
+    }
+
+}

app/src/main/java/com/stephenbain/pagingsamples/ui/playlists/MyPlaylistsViewModel.kt

@@ -4,10 +4,9 @@ import androidx.lifecycle.LiveData
 import androidx.lifecycle.ViewModel
 import androidx.paging.LivePagedListBuilder
 import androidx.paging.PagedList
-import com.stephenbain.pagingsamples.data.datasource.NewReleasesDataSourceFactory
 import com.stephenbain.pagingsamples.data.datasource.PlaylistsBoundaryCallback
 import com.stephenbain.pagingsamples.data.db.PlaylistDao
-import com.stephenbain.pagingsamples.data.domain.GetMyPlaylists
+import com.stephenbain.pagingsamples.data.domain.UpdatePlaylists
 import com.stephenbain.pagingsamples.data.model.Playlist
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
@@ -17,7 +16,7 @@ import javax.inject.Inject
 
 class MyPlaylistsViewModel @Inject constructor(
     private val playlistDao: PlaylistDao,
-    private val getMyPlaylists: GetMyPlaylists
+    private val updatePlaylists: UpdatePlaylists
 ) : ViewModel() {
 
     private val parentJob = Job()
@@ -33,7 +32,7 @@ class MyPlaylistsViewModel @Inject constructor(
 
             val factory = playlistDao.getAllPlaylists()
             return LivePagedListBuilder(factory, config)
-                .setBoundaryCallback(PlaylistsBoundaryCallback(20, scope, playlistDao, getMyPlaylists))
+                .setBoundaryCallback(PlaylistsBoundaryCallback(20, scope, updatePlaylists))
                 .build()
         }