Add Room database for custom playlist

Here we go again!

Doing custom playlist db

app/src/main/java/code/name/monkey/retromusic/db/PlaylistDao.kt

@@ -0,0 +1,19 @@
+package code.name.monkey.retromusic.db
+
+import androidx.room.*
+
+@Dao
+interface PlaylistDao {
+    @Insert
+    suspend fun createPlaylist(playlistEntity: PlaylistEntity)
+
+    @Query("SELECT * FROM PlaylistEntity")
+    suspend fun playlists(): List<PlaylistEntity>
+
+    @Transaction
+    @Query("SELECT * FROM PlaylistEntity")
+    suspend fun playlistsWithSong(): List<PlaylistWithSongs>
+
+    @Insert(onConflict = OnConflictStrategy.REPLACE)
+    suspend fun insertSongs(songEntities: List<SongEntity>)
+}

app/src/main/java/code/name/monkey/retromusic/db/PlaylistDatabase.kt

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+package code.name.monkey.retromusic.db
+
+import android.content.Context
+import androidx.room.Database
+import androidx.room.Room
+import androidx.room.RoomDatabase
+
+@Database(
+    entities = [PlaylistEntity::class, SongEntity::class],
+    version = 4,
+    exportSchema = false
+)
+abstract class PlaylistDatabase : RoomDatabase() {
+    abstract fun playlistDao(): PlaylistDao
+
+    companion object {
+        @Volatile
+        private var INSTANCE: PlaylistDatabase? = null
+
+        fun getDatabase(
+            context: Context
+        ): PlaylistDatabase {
+            return INSTANCE ?: synchronized(this) {
+                val instance = Room.databaseBuilder(
+                    context.applicationContext,
+                    PlaylistDatabase::class.java,
+                    "playlists.db"
+                ).fallbackToDestructiveMigration().build()
+                INSTANCE = instance
+                instance
+            }
+        }
+    }
+}

app/src/main/java/code/name/monkey/retromusic/db/PlaylistEntity.kt

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+package code.name.monkey.retromusic.db
+
+import android.os.Parcelable
+import androidx.room.ColumnInfo
+import androidx.room.Entity
+import androidx.room.PrimaryKey
+import kotlinx.android.parcel.Parcelize
+
+@Entity
+@Parcelize
+class PlaylistEntity(
+    @PrimaryKey
+    @ColumnInfo(name = "playlist_name")
+    val playlistName: String
+) : Parcelable

app/src/main/java/code/name/monkey/retromusic/db/PlaylistWithSongs.kt

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+package code.name.monkey.retromusic.db
+
+import androidx.room.Embedded
+import androidx.room.Relation
+
+data class PlaylistWithSongs(
+    @Embedded val playlistEntity: PlaylistEntity,
+    @Relation(
+        parentColumn = "playlist_name",
+        entityColumn = "playlist_creator_name"
+    ) val songs: List<SongEntity>
+)

app/src/main/java/code/name/monkey/retromusic/db/RoomPlaylistRepository.kt

@@ -0,0 +1,9 @@
+package code.name.monkey.retromusic.db
+
+import androidx.annotation.WorkerThread
+
+class RoomPlaylistRepository(private val playlistDao: PlaylistDao) {
+
+    @WorkerThread
+    suspend fun getPlaylistWithSongs(): List<PlaylistWithSongs> = playlistDao.playlistsWithSong()
+}

app/src/main/java/code/name/monkey/retromusic/db/SongEntity.kt

@@ -0,0 +1,17 @@
+package code.name.monkey.retromusic.db
+
+import androidx.room.ColumnInfo
+import androidx.room.Entity
+import androidx.room.PrimaryKey
+
+@Entity
+class SongEntity(
+    @ColumnInfo(name = "song_id")
+    val songId: Int,
+    @ColumnInfo(name = "playlist_creator_name")
+    val playlistCreatorName: String
+) {
+    @PrimaryKey(autoGenerate = true)
+    @ColumnInfo(name = "song_key")
+    var songPrimaryKey: Long = 0
+}