Use WorkInfo for determining if a backup is already running

Backup and restore is not possible when a backup is running. We used to check notifications for this, but now can use WorkManager's WorkInfo which should be more reliable.

Also, we used to prevent the "Backup now" action when app backup was disabled. But the user may want to do a storage backup. This is now possible.

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

@@ -141,10 +141,17 @@ class SettingsFragment : PreferenceFragmentCompat() {
         super.onViewCreated(view, savedInstanceState)
 
         viewModel.lastBackupTime.observe(viewLifecycleOwner) { time ->
-            setAppBackupStatusSummary(time, viewModel.nextScheduleTimeMillis.value)
+            setAppBackupStatusSummary(
+                lastBackupInMillis = time,
+                nextScheduleTimeMillis = viewModel.appBackupWorkInfo.value?.nextScheduleTimeMillis,
+            )
         }
-        viewModel.nextScheduleTimeMillis.observe(viewLifecycleOwner) { time ->
-            setAppBackupStatusSummary(viewModel.lastBackupTime.value, time)
+        viewModel.appBackupWorkInfo.observe(viewLifecycleOwner) { workInfo ->
+            viewModel.onWorkerStateChanged()
+            setAppBackupStatusSummary(
+                lastBackupInMillis = viewModel.lastBackupTime.value,
+                nextScheduleTimeMillis = workInfo?.nextScheduleTimeMillis,
+            )
         }
 
         val backupFiles: Preference = findPreference("backup_files")!!
@@ -165,7 +172,7 @@ class SettingsFragment : PreferenceFragmentCompat() {
         setAutoRestoreState()
         setAppBackupStatusSummary(
             lastBackupInMillis = viewModel.lastBackupTime.value,
-            nextScheduleTimeMillis = viewModel.nextScheduleTimeMillis.value,
+            nextScheduleTimeMillis = viewModel.appBackupWorkInfo.value?.nextScheduleTimeMillis,
         )
     }
 
@@ -273,11 +280,6 @@ class SettingsFragment : PreferenceFragmentCompat() {
             if (sb.isNotEmpty()) sb.append("\n")
             // set time of next backup
             when (nextScheduleTimeMillis) {
-                -1L -> {
-                    val text = getString(R.string.settings_backup_last_backup_never)
-                    sb.append(getString(R.string.settings_backup_status_next_backup, text))
-                }
-
                 Long.MAX_VALUE -> {
                     val text = if (backupManager.isBackupEnabled && storage?.isUsb != true) {
                         getString(R.string.notification_title)

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

@@ -26,6 +26,7 @@ import androidx.lifecycle.liveData
 import androidx.lifecycle.map
 import androidx.lifecycle.viewModelScope
 import androidx.recyclerview.widget.DiffUtil.calculateDiff
+import androidx.work.WorkInfo
 import androidx.work.WorkManager
 import com.stevesoltys.seedvault.R
 import com.stevesoltys.seedvault.crypto.KeyManager
@@ -71,10 +72,9 @@ internal class SettingsViewModel(
     val backupPossible: LiveData<Boolean> = mBackupPossible
 
     internal val lastBackupTime = metadataManager.lastBackupTime
-    val nextScheduleTimeMillis =
+    internal val appBackupWorkInfo =
         workManager.getWorkInfosForUniqueWorkLiveData(UNIQUE_WORK_NAME).map {
-            if (it.size > 0) it[0].nextScheduleTimeMillis
-            else -1L
+            it.getOrNull(0)
         }
 
     private val mAppStatusList = switchMap(lastBackupTime) {
@@ -139,6 +139,14 @@ internal class SettingsViewModel(
         onStoragePropertiesChanged()
     }
 
+    fun onWorkerStateChanged() {
+        viewModelScope.launch(Dispatchers.IO) {
+            val canDo = settingsManager.canDoBackupNow() &&
+                appBackupWorkInfo.value?.state != WorkInfo.State.RUNNING
+            mBackupPossible.postValue(canDo)
+        }
+    }
+
     private fun onStoragePropertiesChanged() {
         val storage = settingsManager.getStorage() ?: return
 
@@ -164,11 +172,8 @@ internal class SettingsViewModel(
             connectivityManager.registerNetworkCallback(request, networkCallback)
             networkCallback.registered = true
         }
-
-        viewModelScope.launch(Dispatchers.IO) {
-            val canDo = settingsManager.canDoBackupNow()
-            mBackupPossible.postValue(canDo)
-        }
+        // update whether we can do backups right now or not
+        onWorkerStateChanged()
     }
 
     override fun onCleared() {
@@ -180,12 +185,7 @@ internal class SettingsViewModel(
     }
 
     internal fun backupNow() {
-        // maybe replace the check below with one that checks if our transport service is running
-        if (notificationManager.hasActiveBackupNotifications()) {
-            Toast.makeText(app, R.string.notification_backup_already_running, LENGTH_LONG).show()
-        } else if (!backupManager.isBackupEnabled) {
-            Toast.makeText(app, R.string.notification_backup_disabled, LENGTH_LONG).show()
-        } else viewModelScope.launch(Dispatchers.IO) {
+        viewModelScope.launch(Dispatchers.IO) {
             if (settingsManager.isStorageBackupEnabled()) {
                 val i = Intent(app, StorageBackupService::class.java)
                 // this starts an app backup afterwards

app/src/main/java/com/stevesoltys/seedvault/storage/Services.kt

@@ -23,6 +23,7 @@ force running with:
   adb shell cmd jobscheduler run -f com.stevesoltys.seedvault 0
 
  */
+
 internal class StorageBackupJobService : BackupJobService(StorageBackupService::class.java)
 
 internal class StorageBackupService : BackupService() {

app/src/main/java/com/stevesoltys/seedvault/ui/notification/BackupNotificationManager.kt

@@ -192,16 +192,6 @@ internal class BackupNotificationManager(private val context: Context) {
         nm.notify(NOTIFICATION_ID_SUCCESS, notification)
     }
 
-    fun hasActiveBackupNotifications(): Boolean {
-        nm.activeNotifications.forEach {
-            if (it.packageName == context.packageName) {
-                if (it.id == NOTIFICATION_ID_BACKGROUND) return true
-                if (it.id == NOTIFICATION_ID_OBSERVER) return it.isOngoing
-            }
-        }
-        return false
-    }
-
     @SuppressLint("RestrictedApi")
     fun onBackupError() {
         val intent = Intent(context, SettingsActivity::class.java)