Properly schedule/cancel backup workers when backup destination changes

When the user changes to USB storage, we need to cancel current schedulings, because the storage is not always available (maybe can use a trigger URI?). And if moving to a non-USB storage, we need to schedule backups again.

Unfortunately, there are two places in the code where we handle storage location changes. Ideally, those get unified at some point.

app/src/main/java/com/stevesoltys/seedvault/settings/SettingsFragment.kt

@@ -23,7 +23,6 @@ import com.stevesoltys.seedvault.R
 import com.stevesoltys.seedvault.permitDiskReads
 import com.stevesoltys.seedvault.restore.RestoreActivity
 import com.stevesoltys.seedvault.ui.toRelativeTime
-import com.stevesoltys.seedvault.worker.AppBackupWorker
 import org.koin.android.ext.android.inject
 import org.koin.androidx.viewmodel.ext.android.sharedViewModel
 
@@ -128,7 +127,7 @@ class SettingsFragment : PreferenceFragmentCompat() {
             val disable = !(newValue as Boolean)
             // TODO this should really get moved out off the UI layer
             if (disable) {
-                viewModel.cancelBackupWorkers()
+                viewModel.cancelFilesBackup()
                 return@OnPreferenceChangeListener true
             }
             onEnablingStorageBackup()
@@ -215,10 +214,10 @@ class SettingsFragment : PreferenceFragmentCompat() {
         return try {
             backupManager.isBackupEnabled = enabled
             if (enabled) {
-                AppBackupWorker.schedule(requireContext())
+                viewModel.scheduleAppBackup()
                 viewModel.enableCallLogBackup()
             } else {
-                AppBackupWorker.unschedule(requireContext())
+                viewModel.cancelAppBackup()
             }
             backup.isChecked = enabled
             true
@@ -280,7 +279,7 @@ class SettingsFragment : PreferenceFragmentCompat() {
                 }
 
                 Long.MAX_VALUE -> {
-                    val text = if (backupManager.isBackupEnabled) {
+                    val text = if (backupManager.isBackupEnabled && storage?.isUsb != true) {
                         getString(R.string.notification_title)
                     } else {
                         getString(R.string.settings_backup_last_backup_never)
@@ -315,7 +314,7 @@ class SettingsFragment : PreferenceFragmentCompat() {
                         LENGTH_LONG
                     ).show()
                 }
-                viewModel.scheduleBackupWorkers()
+                viewModel.scheduleFilesBackup()
                 backupStorage.isChecked = true
                 dialog.dismiss()
             }

app/src/main/java/com/stevesoltys/seedvault/settings/SettingsViewModel.kt

@@ -129,11 +129,13 @@ internal class SettingsViewModel(
         Log.i(TAG, "onStorageLocationChanged")
         if (storage.isUsb) {
             // disable storage backup if new storage is on USB
-            cancelBackupWorkers()
+            cancelAppBackup()
+            cancelFilesBackup()
         } else {
             // enable it, just in case the previous storage was on USB,
             // also to update the network requirement of the new storage
-            scheduleBackupWorkers()
+            scheduleAppBackup()
+            scheduleFilesBackup()
         }
         onStoragePropertiesChanged()
     }
@@ -245,11 +247,15 @@ internal class SettingsViewModel(
         return keyManager.hasMainKey()
     }
 
-    fun scheduleBackupWorkers() {
+    fun scheduleAppBackup() {
         val storage = settingsManager.getStorage() ?: error("no storage available")
-        if (!storage.isUsb) {
-            if (backupManager.isBackupEnabled) AppBackupWorker.schedule(app)
-            if (settingsManager.isStorageBackupEnabled()) BackupJobService.scheduleJob(
+        if (!storage.isUsb && backupManager.isBackupEnabled) AppBackupWorker.schedule(app)
+    }
+
+    fun scheduleFilesBackup() {
+        val storage = settingsManager.getStorage() ?: error("no storage available")
+        if (!storage.isUsb && settingsManager.isStorageBackupEnabled()) {
+            BackupJobService.scheduleJob(
                 context = app,
                 jobServiceClass = StorageBackupJobService::class.java,
                 periodMillis = HOURS.toMillis(24),
@@ -261,8 +267,11 @@ internal class SettingsViewModel(
         }
     }
 
-    fun cancelBackupWorkers() {
+    fun cancelAppBackup() {
         AppBackupWorker.unschedule(app)
+    }
+
+    fun cancelFilesBackup() {
         BackupJobService.cancelJob(app)
     }
 

app/src/main/java/com/stevesoltys/seedvault/ui/recoverycode/RecoveryCodeViewModel.kt

@@ -102,6 +102,7 @@ internal class RecoveryCodeViewModel(
      */
     fun reinitializeBackupLocation() {
         Log.d(TAG, "Re-initializing backup location...")
+        // TODO this code is almost identical to BackupStorageViewModel#onLocationSet(), unify?
         GlobalScope.launch(Dispatchers.IO) {
             // remove old storage snapshots and clear cache
             storageBackup.deleteAllSnapshots()

app/src/main/java/com/stevesoltys/seedvault/ui/storage/BackupStorageViewModel.kt

@@ -4,6 +4,7 @@ import android.app.Application
 import android.app.backup.BackupProgress
 import android.app.backup.IBackupManager
 import android.app.backup.IBackupObserver
+import android.app.job.JobInfo
 import android.net.Uri
 import android.os.UserHandle
 import android.util.Log
@@ -11,12 +12,15 @@ import androidx.annotation.WorkerThread
 import androidx.lifecycle.viewModelScope
 import com.stevesoltys.seedvault.R
 import com.stevesoltys.seedvault.settings.SettingsManager
+import com.stevesoltys.seedvault.storage.StorageBackupJobService
 import com.stevesoltys.seedvault.transport.TRANSPORT_ID
 import com.stevesoltys.seedvault.worker.AppBackupWorker
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.launch
 import org.calyxos.backup.storage.api.StorageBackup
+import org.calyxos.backup.storage.backup.BackupJobService
 import java.io.IOException
+import java.util.concurrent.TimeUnit
 
 private val TAG = BackupStorageViewModel::class.java.simpleName
 
@@ -31,8 +35,18 @@ internal class BackupStorageViewModel(
 
     override fun onLocationSet(uri: Uri) {
         val isUsb = saveStorage(uri)
+        if (isUsb) {
+            // disable storage backup if new storage is on USB
+            cancelBackupWorkers()
+        } else {
+            // enable it, just in case the previous storage was on USB,
+            // also to update the network requirement of the new storage
+            scheduleBackupWorkers()
+        }
         viewModelScope.launch(Dispatchers.IO) {
             // remove old storage snapshots and clear cache
+            // TODO is this needed? It also does create all 255 chunk folders which takes time
+            //  pass a flag to getCurrentBackupSnapshots() to not create missing folders?
             storageBackup.deleteAllSnapshots()
             storageBackup.clearCache()
             try {
@@ -52,6 +66,27 @@ internal class BackupStorageViewModel(
         }
     }
 
+    private fun scheduleBackupWorkers() {
+        val storage = settingsManager.getStorage() ?: error("no storage available")
+        if (!storage.isUsb) {
+            if (backupManager.isBackupEnabled) AppBackupWorker.schedule(app)
+            if (settingsManager.isStorageBackupEnabled()) BackupJobService.scheduleJob(
+                context = app,
+                jobServiceClass = StorageBackupJobService::class.java,
+                periodMillis = TimeUnit.HOURS.toMillis(24),
+                networkType = if (storage.requiresNetwork) JobInfo.NETWORK_TYPE_UNMETERED
+                else JobInfo.NETWORK_TYPE_NONE,
+                deviceIdle = false,
+                charging = true
+            )
+        }
+    }
+
+    private fun cancelBackupWorkers() {
+        AppBackupWorker.unschedule(app)
+        BackupJobService.cancelJob(app)
+    }
+
     @WorkerThread
     private inner class InitializationObserver(val requestBackup: Boolean) :
         IBackupObserver.Stub() {