Add [Very hacky] genre support

Add a way to load genres! Except it creates duplicates. And requires creating like 20 music cursors. At least it works?

app/build.gradle

@@ -52,12 +52,12 @@ dependencies {
     implementation "androidx.navigation:navigation-fragment-ktx:$navigation_version"
     implementation "androidx.navigation:navigation-ui-ktx:$navigation_version"
 
+    /*
     // Room Database
     def room_version = "2.2.5"
     kapt "androidx.room:room-compiler:$room_version"
     implementation "androidx.room:room-runtime:$room_version"
-    implementation 'androidx.legacy:legacy-support-v4:1.0.0'
-    implementation "androidx.lifecycle:lifecycle-extensions:2.2.0"
+    */
 
     // Lifecycle
     implementation "androidx.lifecycle:lifecycle-extensions:2.2.0"

app/src/main/java/org/oxycblt/auxio/music/MusicLoader.kt

@@ -4,6 +4,7 @@ import android.app.Application
 import android.content.ContentResolver
 import android.database.Cursor
 import android.provider.MediaStore
+import android.provider.MediaStore.Audio.Genres
 import android.provider.MediaStore.Audio.AudioColumns
 import android.util.Log
 import org.oxycblt.auxio.music.models.Song
@@ -17,8 +18,10 @@ enum class MusicLoaderResponse {
 class MusicLoader(private val app: Application) {
 
     var songs = mutableListOf<Song>()
+    var genres = mutableListOf<Pair<Long, String>>()
 
     private var musicCursor: Cursor? = null
+    private var genreCursor: Cursor? = null
 
     val response: MusicLoaderResponse
 
@@ -27,14 +30,15 @@ class MusicLoader(private val app: Application) {
     }
 
     private fun findMusic(): MusicLoaderResponse {
-        try {
-            musicCursor = getCursor(
+        genreCursor = getGenreCursor(
             app.contentResolver
         )
 
-            Log.i(this::class.simpleName, "Starting music search...")
+        useGenreCursor()
 
-            useCursor()
+        indexMusic()
+
+        try {
         } catch (error: Exception) {
             Log.e(this::class.simpleName, "Something went horribly wrong.")
             error.printStackTrace()
@@ -63,14 +67,30 @@ class MusicLoader(private val app: Application) {
         }
     }
 
-    private fun getCursor(resolver: ContentResolver): Cursor? {
+    private fun getGenreCursor(resolver: ContentResolver): Cursor? {
+        Log.i(this::class.simpleName, "Getting genre cursor.")
+
+        // Get every Genre indexed by the android system, for some reason
+        // you cant directly get this from the plain music cursor.
+        return resolver.query(
+            Genres.EXTERNAL_CONTENT_URI,
+            arrayOf(
+                Genres._ID, // 0
+                Genres.NAME // 1
+            ),
+            null, null,
+            Genres.DEFAULT_SORT_ORDER
+        )
+    }
+
+    private fun getMusicCursor(resolver: ContentResolver, genreId: Long): Cursor? {
         Log.i(this::class.simpleName, "Getting music cursor.")
 
         // Get all the values that can be retrieved by the cursor.
         // The rest are retrieved using MediaMetadataExtractor and
         // stored into a database.
         return resolver.query(
-            MediaStore.Audio.Media.EXTERNAL_CONTENT_URI,
+            Genres.Members.getContentUri("external", genreId),
             arrayOf(
                 AudioColumns._ID, // 0
                 AudioColumns.DISPLAY_NAME, // 1
@@ -86,11 +106,54 @@ class MusicLoader(private val app: Application) {
         )
     }
 
-    // Use the cursor index music files from the shared storage, returns true if any were found.
-    private fun useCursor() {
+    // Use the genre cursor to index all the genres the android system has indexed.
+    private fun useGenreCursor() {
+        // TODO: Move genre to its own model, even if its just two values
+
+        genreCursor?.use { cursor ->
+
+            // Don't even bother running if there's nothing to process.
+            if (cursor.count == 0) {
+                return
+            }
+
+            val idIndex = cursor.getColumnIndexOrThrow(Genres._ID)
+            val nameIndex = cursor.getColumnIndexOrThrow(Genres.NAME)
+
+            while (cursor.moveToNext()) {
+                genres.add(
+                    Pair<Long, String>(
+                        cursor.getLong(idIndex),
+                        cursor.getString(nameIndex)
+                    )
+                )
+
+                Log.i(this::class.simpleName, cursor.getString(nameIndex))
+            }
+
+            cursor.close()
+        }
+
+        Log.i(this::class.simpleName, "Retrieved " + genres.size.toString() + " Genres.")
+    }
+
+    // Use the cursor index music files from the shared storage.
+    private fun indexMusic() {
+        Log.i(this::class.simpleName, "Starting music search...")
+
+        // So, android has a brain aneurysm if you try to get an audio genre through
+        // AudioColumns. As a result, I just index every genre's name & ID, create a cursor
+        // of music for that genres ID, and then load and iterate through them normally,
+        // creating using the genres name as that songs Genre.
+
+        // God why do I have to do this
+        for (genre in genres) {
+            val musicCursor = getMusicCursor(app.contentResolver, genre.first)
+
             musicCursor?.use { cursor ->
 
-            // Don't run the more expensive file loading operations if there is no music to index.
+                // Don't run the more expensive file loading operations if there
+                // is no music to index.
                 if (cursor.count == 0) {
                     return
                 }
@@ -106,9 +169,10 @@ class MusicLoader(private val app: Application) {
 
                 while (cursor.moveToNext()) {
                     val id = cursor.getLong(idIndex)
+                    val display = cursor.getString(displayIndex)
 
                     // Get the basic metadata from the cursor
-                val title = cursor.getString(titleIndex) ?: cursor.getString(displayIndex)
+                    val title = cursor.getString(titleIndex) ?: display
                     val artist = cursor.getString(artistIndex)
                     val album = cursor.getString(albumIndex)
                     val year = cursor.getInt(yearIndex)
@@ -120,7 +184,7 @@ class MusicLoader(private val app: Application) {
                     songs.add(
                         Song(
                             id, title, artist, album,
-                        year, track, duration
+                            genre.second, year, track, duration
                         )
                     )
                 }
@@ -129,3 +193,4 @@ class MusicLoader(private val app: Application) {
             }
         }
     }
+}

app/src/main/java/org/oxycblt/auxio/music/models/Song.kt

@@ -6,6 +6,7 @@ data class Song(
     val name: String?,
     val artist: String?,
     val album: String?,
+    val genre: String?,
     val year: Int,
     val track: Int,
     val duration: Long,