Make it clear which ID the OfflineServer has (-1)

Also provide migration path to future version

ultrasonic/src/main/kotlin/org/moire/ultrasonic/adapters/ServerRowAdapter.kt

@@ -1,4 +1,4 @@
-package org.moire.ultrasonic.fragment
+package org.moire.ultrasonic.adapters
 
 import android.content.Context
 import android.graphics.drawable.Drawable

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

@@ -19,8 +19,6 @@ import timber.log.Timber
 /**
  * This class can be used to retrieve the properties of the Active Server
  * It caches the settings read up from the DB to improve performance.
- *
- * TODO: There seems to be some confusion whether offline id is 0 or -1. Clean this up (carefully!)
  */
 class ActiveServerProvider(
     private val repository: ServerSettingDao
@@ -35,7 +33,7 @@ class ActiveServerProvider(
      */
     @JvmOverloads
     fun getActiveServer(serverId: Int = getActiveServerId()): ServerSetting {
-        if (serverId > 0) {
+        if (serverId > OFFLINE_DB_ID) {
             if (cachedServer != null && cachedServer!!.id == serverId) return cachedServer!!
 
             // Ideally this is the only call where we block the thread while using the repository
@@ -53,22 +51,11 @@ class ActiveServerProvider(
                 return cachedServer!!
             }
 
-            setActiveServerId(0)
+            // Fallback to Offline
+            setActiveServerId(OFFLINE_DB_ID)
         }
 
-        return ServerSetting(
+        return OFFLINE_DB
-            id = -1,
-            index = 0,
-            name = UApp.applicationContext().getString(R.string.main_offline),
-            url = "http://localhost",
-            userName = "",
-            password = "",
-            jukeboxByDefault = false,
-            allowSelfSignedCertificate = false,
-            ldapSupport = false,
-            musicFolderId = "",
-            minimumApiVersion = null
-        )
     }
 
     /**
@@ -77,9 +64,9 @@ class ActiveServerProvider(
      */
     fun setActiveServerByIndex(index: Int) {
         Timber.d("setActiveServerByIndex $index")
-        if (index < 1) {
+        if (index <= OFFLINE_DB_INDEX) {
             // Offline mode is selected
-            setActiveServerId(0)
+            setActiveServerId(OFFLINE_DB_ID)
             return
         }
 
@@ -103,22 +90,20 @@ class ActiveServerProvider(
 
         Timber.i("Switching to new database, id:$activeServer")
         cachedServerId = activeServer
-        return Room.databaseBuilder(
+        return buildDatabase(cachedServerId)
-            UApp.applicationContext(),
-            MetaDatabase::class.java,
-            METADATA_DB + cachedServerId
-        )
-            .fallbackToDestructiveMigrationOnDowngrade()
-            .build()
     }
 
     val offlineMetaDatabase: MetaDatabase by lazy {
-        Room.databaseBuilder(
+        buildDatabase(OFFLINE_DB_ID)
+    }
+
+    private fun buildDatabase(id: Int?): MetaDatabase {
+        return Room.databaseBuilder(
             UApp.applicationContext(),
             MetaDatabase::class.java,
-            METADATA_DB + 0
+            METADATA_DB + id
         )
-            .fallbackToDestructiveMigrationOnDowngrade()
+            .fallbackToDestructiveMigration()
             .build()
     }
 
@@ -177,8 +162,24 @@ class ActiveServerProvider(
     }
 
     companion object {
-
         const val METADATA_DB = "$DB_FILENAME-meta-"
+        const val OFFLINE_DB_ID = -1
+        const val OFFLINE_DB_INDEX = 0
+
+        val OFFLINE_DB = ServerSetting(
+            id = OFFLINE_DB_ID,
+            index = OFFLINE_DB_INDEX,
+            name = UApp.applicationContext().getString(R.string.main_offline),
+            url = "http://localhost",
+            userName = "",
+            password = "",
+            jukeboxByDefault = false,
+            allowSelfSignedCertificate = false,
+            ldapSupport = false,
+            musicFolderId = "",
+            minimumApiVersion = null
+        )
+
         val liveActiveServerId: MutableLiveData<Int> = MutableLiveData(getActiveServerId())
 
         /**
@@ -186,7 +187,7 @@ class ActiveServerProvider(
          * @return True, if the "Offline" mode is selected
          */
         fun isOffline(): Boolean {
-            return getActiveServerId() < 1
+            return getActiveServerId() == OFFLINE_DB_ID
         }
 
         /**

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

@@ -9,7 +9,11 @@ import androidx.sqlite.db.SupportSQLiteDatabase
  * Room Database to be used to store global data for the whole app.
  * This could be settings or data that are not specific to any remote music database
  */
-@Database(entities = [ServerSetting::class], version = 4)
+@Database(
+    entities = [ServerSetting::class],
+    version = 4,
+    exportSchema = true
+)
 abstract class AppDatabase : RoomDatabase() {
 
     /**
@@ -175,3 +179,89 @@ val MIGRATION_4_3: Migration = object : Migration(4, 3) {
         )
     }
 }
+
+val MIGRATION_4_5: Migration = object : Migration(4, 5) {
+    override fun migrate(database: SupportSQLiteDatabase) {
+        database.execSQL(
+            """
+                    CREATE TABLE IF NOT EXISTS `_new_ServerSetting` (
+                    `id` INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL, 
+                    `index` INTEGER NOT NULL, 
+                    `name` TEXT NOT NULL, 
+                    `url` TEXT NOT NULL, 
+                    `color` INTEGER, 
+                    `userName` TEXT NOT NULL, 
+                    `password` TEXT NOT NULL, 
+                    `jukeboxByDefault` INTEGER NOT NULL, 
+                    `allowSelfSignedCertificate` INTEGER NOT NULL, 
+                    `ldapSupport` INTEGER NOT NULL, 
+                    `musicFolderId` TEXT, 
+                    `minimumApiVersion` TEXT, 
+                    `chatSupport` INTEGER, 
+                    `bookmarkSupport` INTEGER, 
+                    `shareSupport` INTEGER, 
+                    `podcastSupport` INTEGER
+                    )
+            """.trimIndent()
+        )
+        database.execSQL(
+            """
+                    INSERT INTO `_new_ServerSetting` (
+                    `ldapSupport`,`musicFolderId`,`color`,`index`,`userName`,`minimumApiVersion`,
+                    `jukeboxByDefault`,`url`,`password`,`shareSupport`,`bookmarkSupport`,`name`,
+                    `podcastSupport`,`id`,`allowSelfSignedCertificate`,`chatSupport`
+                    ) 
+                    SELECT `ldapSupport`,`musicFolderId`,`color`,`index`,`userName`,
+                    `minimumApiVersion`,`jukeboxByDefault`,`url`,`password`,`shareSupport`,
+                    `bookmarkSupport`,`name`,`podcastSupport`,`id`,`allowSelfSignedCertificate`,
+                    `chatSupport` 
+                    FROM `ServerSetting`
+            """.trimIndent()
+        )
+        database.execSQL("DROP TABLE `ServerSetting`")
+        database.execSQL("ALTER TABLE `_new_ServerSetting` RENAME TO `ServerSetting`")
+    }
+}
+
+val MIGRATION_5_4: Migration = object : Migration(5, 4) {
+    override fun migrate(database: SupportSQLiteDatabase) {
+        database.execSQL(
+            """
+                    CREATE TABLE IF NOT EXISTS `_new_ServerSetting` (
+                    `id` INTEGER PRIMARY KEY NOT NULL, 
+                    `index` INTEGER NOT NULL, 
+                    `name` TEXT NOT NULL, 
+                    `url` TEXT NOT NULL, 
+                    `color` INTEGER, 
+                    `userName` TEXT NOT NULL, 
+                    `password` TEXT NOT NULL, 
+                    `jukeboxByDefault` INTEGER NOT NULL, 
+                    `allowSelfSignedCertificate` INTEGER NOT NULL, 
+                    `ldapSupport` INTEGER NOT NULL, 
+                    `musicFolderId` TEXT, 
+                    `minimumApiVersion` TEXT, 
+                    `chatSupport` INTEGER, 
+                    `bookmarkSupport` INTEGER, 
+                    `shareSupport` INTEGER, 
+                    `podcastSupport` INTEGER
+                    )
+            """.trimIndent()
+        )
+        database.execSQL(
+            """
+                    INSERT INTO `_new_ServerSetting` (
+                    `ldapSupport`,`musicFolderId`,`color`,`index`,`userName`,`minimumApiVersion`,
+                    `jukeboxByDefault`,`url`,`password`,`shareSupport`,`bookmarkSupport`,`name`,
+                    `podcastSupport`,`id`,`allowSelfSignedCertificate`,`chatSupport`
+                    ) 
+                    SELECT `ldapSupport`,`musicFolderId`,`color`,`index`,`userName`,
+                    `minimumApiVersion`,`jukeboxByDefault`,`url`,`password`,`shareSupport`,
+                    `bookmarkSupport`,`name`,`podcastSupport`,`id`,`allowSelfSignedCertificate`,
+                    `chatSupport` 
+                    FROM `ServerSetting`
+            """.trimIndent()
+        )
+        database.execSQL("DROP TABLE `ServerSetting`")
+        database.execSQL("ALTER TABLE `_new_ServerSetting` RENAME TO `ServerSetting`")
+    }
+}

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

@@ -39,7 +39,4 @@ data class ServerSetting(
     constructor() : this (
         -1, 0, "", "", null, "", "", false, false, false, null, null
     )
-    constructor(name: String, url: String) : this(
-        -1, 0, name, url, null, "", "", false, false, false, null, null
-    )
 }

ultrasonic/src/main/kotlin/org/moire/ultrasonic/di/AppPermanentStorageModule.kt

@@ -12,6 +12,8 @@ import org.moire.ultrasonic.data.MIGRATION_2_3
 import org.moire.ultrasonic.data.MIGRATION_3_2
 import org.moire.ultrasonic.data.MIGRATION_3_4
 import org.moire.ultrasonic.data.MIGRATION_4_3
+import org.moire.ultrasonic.data.MIGRATION_4_5
+import org.moire.ultrasonic.data.MIGRATION_5_4
 import org.moire.ultrasonic.model.ServerSettingsModel
 import org.moire.ultrasonic.util.Settings
 
@@ -36,6 +38,8 @@ val appPermanentStorage = module {
             .addMigrations(MIGRATION_3_2)
             .addMigrations(MIGRATION_3_4)
             .addMigrations(MIGRATION_4_3)
+            .addMigrations(MIGRATION_4_5)
+            .addMigrations(MIGRATION_5_4)
             .build()
     }
 

ultrasonic/src/main/kotlin/org/moire/ultrasonic/fragment/ServerSelectorFragment.kt

@@ -15,6 +15,7 @@ import kotlinx.coroutines.withContext
 import org.koin.android.ext.android.inject
 import org.koin.androidx.viewmodel.ext.android.viewModel
 import org.moire.ultrasonic.R
+import org.moire.ultrasonic.adapters.ServerRowAdapter
 import org.moire.ultrasonic.data.ActiveServerProvider
 import org.moire.ultrasonic.fragment.EditServerFragment.Companion.EDIT_SERVER_INTENT_INDEX
 import org.moire.ultrasonic.model.ServerSettingsModel
@@ -103,11 +104,10 @@ class ServerSelectorFragment : Fragment() {
         super.onResume()
         val serverList = serverSettingsModel.getServerList()
         serverList.observe(
-            this,
+            this
-            { t ->
+        ) { t ->
             serverRowAdapter!!.setData(t.toTypedArray())
         }
-        )
     }
 
     /**