Introduce StoragePluginManager to handle storage plugins

and allow changing them dynamically. So far plugins were injected into the dependency graph and couldn't be changed at runtime, only their config could. Now we have the infrastructure in place to really allow for more than one plugin.

app/src/androidTest/java/com/stevesoltys/seedvault/KoinInstrumentationTestApp.kt

@@ -41,19 +41,20 @@ class KoinInstrumentationTestApp : App() {
 
             viewModel {
                 currentRestoreViewModel =
-                    spyk(RestoreViewModel(context, get(), get(), get(), get(), get(), get()))
+                    spyk(RestoreViewModel(context, get(), get(), get(), get(), get(), get(), get()))
                 currentRestoreViewModel!!
             }
 
             viewModel {
-                currentBackupStorageViewModel =
+                val viewModel =
-                    spyk(BackupStorageViewModel(context, get(), get(), get(), get()))
+                    BackupStorageViewModel(context, get(), get(), get(), get(), get(), get(), get())
+                currentBackupStorageViewModel = spyk(viewModel)
                 currentBackupStorageViewModel!!
             }
 
             viewModel {
                 currentRestoreStorageViewModel =
-                    spyk(RestoreStorageViewModel(context, get(), get()))
+                    spyk(RestoreStorageViewModel(context, get(), get(), get(), get()))
                 currentRestoreStorageViewModel!!
             }
         }

app/src/androidTest/java/com/stevesoltys/seedvault/PluginTest.kt

@@ -1,5 +1,6 @@
 package com.stevesoltys.seedvault
 
+import android.net.Uri
 import androidx.test.core.content.pm.PackageInfoBuilder
 import androidx.test.ext.junit.runners.AndroidJUnit4
 import androidx.test.filters.MediumTest
@@ -28,20 +29,24 @@ import org.koin.core.component.KoinComponent
 import org.koin.core.component.inject
 
 @RunWith(AndroidJUnit4::class)
-@Suppress("BlockingMethodInNonBlockingContext")
 @MediumTest
 class PluginTest : KoinComponent {
 
     private val context = InstrumentationRegistry.getInstrumentation().targetContext
     private val settingsManager: SettingsManager by inject()
     private val mockedSettingsManager: SettingsManager = mockk()
-    private val storage = DocumentsStorage(context, mockedSettingsManager)
+    private val storage = DocumentsStorage(
+        appContext = context,
+        settingsManager = mockedSettingsManager,
+        safStorage = settingsManager.getSafStorage() ?: error("No SAF storage"),
+    )
 
-    private val storagePlugin: StoragePlugin = DocumentsProviderStoragePlugin(context, storage)
+    private val storagePlugin: StoragePlugin<Uri> = DocumentsProviderStoragePlugin(context, storage)
 
     @Suppress("Deprecation")
-    private val legacyStoragePlugin: LegacyStoragePlugin =
+    private val legacyStoragePlugin: LegacyStoragePlugin = DocumentsProviderLegacyPlugin(context) {
-        DocumentsProviderLegacyPlugin(context, storage)
+        storage
+    }
 
     private val token = System.currentTimeMillis() - 365L * 24L * 60L * 60L * 1000L
     private val packageInfo = PackageInfoBuilder.newBuilder().setPackageName("org.example").build()
@@ -76,8 +81,6 @@ class PluginTest : KoinComponent {
     fun testInitializationAndRestoreSets() = runBlocking(Dispatchers.IO) {
         // no backups available initially
         assertEquals(0, storagePlugin.getAvailableBackups()?.toList()?.size)
-        val s = settingsManager.getSafStorage() ?: error("no storage")
-        assertFalse(storagePlugin.hasBackup(s))
 
         // prepare returned tokens requested when initializing device
         every { mockedSettingsManager.getToken() } returnsMany listOf(token, token + 1, token + 1)
@@ -92,7 +95,6 @@ class PluginTest : KoinComponent {
 
         // one backup available now
         assertEquals(1, storagePlugin.getAvailableBackups()?.toList()?.size)
-        assertTrue(storagePlugin.hasBackup(s))
 
         // initializing again (with another restore set) does add a restore set
         storagePlugin.startNewRestoreSet(token + 1)
@@ -100,7 +102,6 @@ class PluginTest : KoinComponent {
         storagePlugin.getOutputStream(token + 1, FILE_BACKUP_METADATA)
             .writeAndClose(getRandomByteArray())
         assertEquals(2, storagePlugin.getAvailableBackups()?.toList()?.size)
-        assertTrue(storagePlugin.hasBackup(s))
 
         // initializing again (without new restore set) doesn't change number of restore sets
         storagePlugin.initializeDevice()

app/src/androidTest/java/com/stevesoltys/seedvault/plugins/saf/DocumentsStorageTest.kt

@@ -39,13 +39,16 @@ import java.io.IOException
 import kotlin.random.Random
 
 @RunWith(AndroidJUnit4::class)
-@Suppress("BlockingMethodInNonBlockingContext")
 @MediumTest
 class DocumentsStorageTest : KoinComponent {
 
     private val context = InstrumentationRegistry.getInstrumentation().targetContext
     private val settingsManager by inject<SettingsManager>()
-    private val storage = DocumentsStorage(context, settingsManager)
+    private val storage = DocumentsStorage(
+        appContext = context,
+        settingsManager = settingsManager,
+        safStorage = settingsManager.getSafStorage() ?: error("No SAF storage"),
+    )
 
     private val filename = getRandomBase64()
     private lateinit var file: DocumentFile

app/src/androidTest/java/com/stevesoltys/seedvault/transport/backup/PackageServiceTest.kt

@@ -24,7 +24,7 @@ class PackageServiceTest : KoinComponent {
 
     private val settingsManager: SettingsManager by inject()
 
-    private val storagePlugin: StoragePlugin by inject()
+    private val storagePlugin: StoragePlugin<*> by inject()
 
     @Test
     fun testNotAllowedPackages() {

app/src/main/java/com/stevesoltys/seedvault/App.kt

@@ -13,13 +13,14 @@ import android.os.StrictMode
 import android.os.UserHandle
 import android.os.UserManager
 import android.provider.Settings
-import androidx.work.WorkManager
 import androidx.work.ExistingPeriodicWorkPolicy.UPDATE
+import androidx.work.WorkManager
 import com.stevesoltys.seedvault.crypto.cryptoModule
 import com.stevesoltys.seedvault.header.headerModule
 import com.stevesoltys.seedvault.metadata.MetadataManager
 import com.stevesoltys.seedvault.metadata.metadataModule
-import com.stevesoltys.seedvault.plugins.saf.documentsProviderModule
+import com.stevesoltys.seedvault.plugins.StoragePluginManager
+import com.stevesoltys.seedvault.plugins.saf.storagePluginModuleSaf
 import com.stevesoltys.seedvault.restore.RestoreViewModel
 import com.stevesoltys.seedvault.restore.install.installModule
 import com.stevesoltys.seedvault.settings.AppListRetriever
@@ -54,15 +55,41 @@ open class App : Application() {
     private val appModule = module {
         single { SettingsManager(this@App) }
         single { BackupNotificationManager(this@App) }
+        single { StoragePluginManager(this@App, get(), get()) }
         single { Clock() }
         factory<IBackupManager> { IBackupManager.Stub.asInterface(getService(BACKUP_SERVICE)) }
         factory { AppListRetriever(this@App, get(), get(), get()) }
 
-        viewModel { SettingsViewModel(this@App, get(), get(), get(), get(), get(), get(), get()) }
+        viewModel {
+            SettingsViewModel(
+                app = this@App,
+                settingsManager = get(),
+                keyManager = get(),
+                pluginManager = get(),
+                metadataManager = get(),
+                appListRetriever = get(),
+                storageBackup = get(),
+                backupManager = get(),
+                backupInitializer = get(),
+            )
+        }
         viewModel { RecoveryCodeViewModel(this@App, get(), get(), get(), get(), get(), get()) }
-        viewModel { BackupStorageViewModel(this@App, get(), get(), get(), get()) }
+        viewModel { BackupStorageViewModel(this@App, get(), get(), get(), get(), get(), get()) }
-        viewModel { RestoreStorageViewModel(this@App, get(), get()) }
+        viewModel { RestoreStorageViewModel(this@App, get(), get(), get()) }
-        viewModel { RestoreViewModel(this@App, get(), get(), get(), get(), get(), get()) }
+        viewModel { RestoreViewModel(this@App, get(), get(), get(), get(), get(), get(), get()) }
+        viewModel {
+            BackupStorageViewModel(
+                app = this@App,
+                backupManager = get(),
+                backupInitializer = get(),
+                storageBackup = get(),
+                safHandler = get(),
+                settingsManager = get(),
+                storagePluginManager = get(),
+            )
+        }
+        viewModel { RestoreStorageViewModel(this@App, get(), get(), get()) }
+        viewModel { RestoreViewModel(this@App, get(), get(), get(), get(), get(), get(), get()) }
         viewModel { FileSelectionViewModel(this@App, get()) }
     }
 
@@ -100,7 +127,7 @@ open class App : Application() {
         cryptoModule,
         headerModule,
         metadataModule,
-        documentsProviderModule, // storage plugin
+        storagePluginModuleSaf, // storage plugin
         backupModule,
         restoreModule,
         installModule,

app/src/main/java/com/stevesoltys/seedvault/plugins/StoragePlugin.kt

@@ -1,13 +1,11 @@
 package com.stevesoltys.seedvault.plugins
 
 import android.app.backup.RestoreSet
-import androidx.annotation.WorkerThread
-import com.stevesoltys.seedvault.plugins.saf.SafStorage
 import java.io.IOException
 import java.io.InputStream
 import java.io.OutputStream
 
-interface StoragePlugin {
+interface StoragePlugin<T> {
 
     /**
      * Returns true if the plugin is working, or false if it isn't.
@@ -53,14 +51,6 @@ interface StoragePlugin {
     @Throws(IOException::class)
     suspend fun removeData(token: Long, name: String)
 
-    /**
-     * Searches if there's really a backup available in the given storage location.
-     * Returns true if at least one was found and false otherwise.
-     */
-    @WorkerThread
-    @Throws(IOException::class)
-    suspend fun hasBackup(safStorage: SafStorage): Boolean
-
     /**
      * Get the set of all backups currently available for restore.
      *

app/src/main/java/com/stevesoltys/seedvault/plugins/StoragePluginManager.kt

@@ -0,0 +1,137 @@
+/*
+ * SPDX-FileCopyrightText: 2024 The Calyx Institute
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package com.stevesoltys.seedvault.plugins
+
+import android.content.Context
+import android.net.ConnectivityManager
+import android.net.NetworkCapabilities.NET_CAPABILITY_INTERNET
+import androidx.annotation.WorkerThread
+import com.stevesoltys.seedvault.getStorageContext
+import com.stevesoltys.seedvault.permitDiskReads
+import com.stevesoltys.seedvault.plugins.saf.DocumentsProviderStoragePlugin
+import com.stevesoltys.seedvault.plugins.saf.DocumentsStorage
+import com.stevesoltys.seedvault.plugins.saf.SafFactory
+import com.stevesoltys.seedvault.settings.SettingsManager
+import com.stevesoltys.seedvault.settings.StoragePluginEnum
+
+abstract class StorageProperties<T> {
+    abstract val config: T
+    abstract val name: String
+    abstract val isUsb: Boolean
+    abstract val requiresNetwork: Boolean
+
+    @WorkerThread
+    abstract fun isUnavailableUsb(context: Context): Boolean
+
+    /**
+     * Returns true if this is storage that requires network access,
+     * but it isn't available right now.
+     */
+    fun isUnavailableNetwork(context: Context, allowMetered: Boolean): Boolean {
+        return requiresNetwork && !hasUnmeteredInternet(context, allowMetered)
+    }
+
+    private fun hasUnmeteredInternet(context: Context, allowMetered: Boolean): Boolean {
+        val cm = context.getSystemService(ConnectivityManager::class.java) ?: return false
+        val isMetered = cm.isActiveNetworkMetered
+        val capabilities = cm.getNetworkCapabilities(cm.activeNetwork) ?: return false
+        return capabilities.hasCapability(NET_CAPABILITY_INTERNET) &&
+            (allowMetered || !isMetered)
+    }
+}
+
+class StoragePluginManager(
+    private val context: Context,
+    private val settingsManager: SettingsManager,
+    safFactory: SafFactory,
+) {
+
+    private var _appPlugin: StoragePlugin<*>?
+    private var _filesPlugin: org.calyxos.backup.storage.api.StoragePlugin?
+    private var _storageProperties: StorageProperties<*>?
+
+    val appPlugin: StoragePlugin<*>
+        @Synchronized
+        get() {
+            return _appPlugin ?: error("App plugin was loaded, but still null")
+        }
+
+    val filesPlugin: org.calyxos.backup.storage.api.StoragePlugin
+        @Synchronized
+        get() {
+            return _filesPlugin ?: error("Files plugin was loaded, but still null")
+        }
+
+    val storageProperties: StorageProperties<*>?
+        @Synchronized
+        get() {
+            return _storageProperties
+        }
+
+    init {
+        when (settingsManager.storagePluginType) {
+            StoragePluginEnum.SAF -> {
+                val safStorage = settingsManager.getSafStorage() ?: error("No SAF storage saved")
+                val documentsStorage = DocumentsStorage(context, settingsManager, safStorage)
+                _appPlugin = safFactory.createAppStoragePlugin(safStorage, documentsStorage)
+                _filesPlugin = safFactory.createFilesStoragePlugin(safStorage, documentsStorage)
+                _storageProperties = safStorage
+            }
+
+            null -> {
+                _appPlugin = null
+                _filesPlugin = null
+                _storageProperties = null
+            }
+        }
+    }
+
+    fun isValidAppPluginSet(): Boolean {
+        if (_appPlugin == null || _filesPlugin == null) return false
+        if (_appPlugin is DocumentsProviderStoragePlugin) {
+            val storage = settingsManager.getSafStorage() ?: return false
+            if (storage.isUsb) return true
+            return permitDiskReads {
+                storage.getDocumentFile(context).isDirectory
+            }
+        }
+        return true
+    }
+
+    /**
+     * Changes the storage plugins and current [StorageProperties].
+     *
+     * IMPORTANT: Do no call this while current plugins are being used,
+     *            e.g. while backup/restore operation is still running.
+     */
+    fun <T> changePlugins(
+        storageProperties: StorageProperties<T>,
+        appPlugin: StoragePlugin<T>,
+        filesPlugin: org.calyxos.backup.storage.api.StoragePlugin,
+    ) {
+        settingsManager.setStoragePlugin(appPlugin)
+        _storageProperties = storageProperties
+        _appPlugin = appPlugin
+        _filesPlugin = filesPlugin
+    }
+
+    /**
+     * Check if we are able to do backups now by examining possible pre-conditions
+     * such as plugged-in flash drive or internet access.
+     *
+     * Should be run off the UI thread (ideally I/O) because of disk access.
+     *
+     * @return true if a backup is possible, false if not.
+     */
+    @WorkerThread
+    fun canDoBackupNow(): Boolean {
+        val storage = storageProperties ?: return false
+        val systemContext = context.getStorageContext { storage.isUsb }
+        return !storage.isUnavailableUsb(systemContext) &&
+            !storage.isUnavailableNetwork(context, settingsManager.useMeteredNetwork)
+    }
+
+}

app/src/main/java/com/stevesoltys/seedvault/plugins/saf/DocumentsProviderLegacyPlugin.kt

@@ -10,12 +10,13 @@ import java.io.IOException
 import java.io.InputStream
 
 @WorkerThread
-@Suppress("BlockingMethodInNonBlockingContext", "Deprecation") // all methods do I/O
+@Suppress("Deprecation")
 internal class DocumentsProviderLegacyPlugin(
     private val context: Context,
-    private val storage: DocumentsStorage,
+    private val storageGetter: () -> DocumentsStorage,
 ) : LegacyStoragePlugin {
 
+    private val storage get() = storageGetter()
     private var packageDir: DocumentFile? = null
     private var packageChildren: List<DocumentFile>? = null
 

app/src/main/java/com/stevesoltys/seedvault/plugins/saf/DocumentsProviderModule.kt

@@ -1,14 +1,22 @@
 package com.stevesoltys.seedvault.plugins.saf
 
 import com.stevesoltys.seedvault.plugins.LegacyStoragePlugin
-import com.stevesoltys.seedvault.plugins.StoragePlugin
+import com.stevesoltys.seedvault.settings.SettingsManager
 import org.koin.android.ext.koin.androidContext
 import org.koin.dsl.module
 
-val documentsProviderModule = module {
+val storagePluginModuleSaf = module {
-    single { DocumentsStorage(androidContext(), get()) }
+    single { SafFactory(androidContext(), get(), get()) }
+    single { SafHandler(androidContext(), get(), get(), get()) }
 
-    single<StoragePlugin> { DocumentsProviderStoragePlugin(androidContext(), get()) }
     @Suppress("Deprecation")
-    single<LegacyStoragePlugin> { DocumentsProviderLegacyPlugin(androidContext(), get()) }
+    single<LegacyStoragePlugin> {
+        DocumentsProviderLegacyPlugin(
+            context = androidContext(),
+            storageGetter = {
+                val safStorage = get<SettingsManager>().getSafStorage() ?: error("No SAF storage")
+                DocumentsStorage(androidContext(), get(), safStorage)
+            },
+        )
+    }
 }

app/src/main/java/com/stevesoltys/seedvault/plugins/saf/DocumentsProviderStoragePlugin.kt

@@ -2,6 +2,7 @@ package com.stevesoltys.seedvault.plugins.saf
 
 import android.content.Context
 import android.content.pm.PackageManager
+import android.net.Uri
 import android.util.Log
 import androidx.documentfile.provider.DocumentFile
 import com.stevesoltys.seedvault.getStorageContext
@@ -16,19 +17,15 @@ import java.io.OutputStream
 
 private val TAG = DocumentsProviderStoragePlugin::class.java.simpleName
 
-@Suppress("BlockingMethodInNonBlockingContext")
 internal class DocumentsProviderStoragePlugin(
     private val appContext: Context,
     private val storage: DocumentsStorage,
-) : StoragePlugin {
+) : StoragePlugin<Uri> {
 
     /**
      * Attention: This context might be from a different user. Use with care.
      */
-    private val context: Context
+    private val context: Context get() = appContext.getStorageContext { storage.safStorage.isUsb }
-        get() = appContext.getStorageContext {
-            storage.safStorage?.isUsb == true
-        }
 
     private val packageManager: PackageManager = appContext.packageManager
 
@@ -77,16 +74,6 @@ internal class DocumentsProviderStoragePlugin(
         if (!file.delete()) throw IOException("Failed to delete $name")
     }
 
-    @Throws(IOException::class)
-    override suspend fun hasBackup(safStorage: SafStorage): Boolean {
-        // potentially get system user context if needed here
-        val c = appContext.getStorageContext { safStorage.isUsb }
-        val parent = DocumentFile.fromTreeUri(c, safStorage.uri) ?: throw AssertionError()
-        val rootDir = parent.findFileBlocking(c, DIRECTORY_ROOT) ?: return false
-        val backupSets = getBackups(c, rootDir)
-        return backupSets.isNotEmpty()
-    }
-
     override suspend fun getAvailableBackups(): Sequence<EncryptedMetadata>? {
         val rootDir = storage.rootBackupDir ?: return null
         val backupSets = getBackups(context, rootDir)
@@ -110,7 +97,6 @@ internal class DocumentsProviderStoragePlugin(
 
 class BackupSet(val token: Long, val metadataFile: DocumentFile)
 
-@Suppress("BlockingMethodInNonBlockingContext")
 internal suspend fun getBackups(context: Context, rootDir: DocumentFile): List<BackupSet> {
     val backupSets = ArrayList<BackupSet>()
     val files = try {

app/src/main/java/com/stevesoltys/seedvault/plugins/saf/DocumentsStorage.kt

@@ -1,5 +1,3 @@
-@file:Suppress("BlockingMethodInNonBlockingContext")
-
 package com.stevesoltys.seedvault.plugins.saf
 
 import android.content.ContentResolver
@@ -43,27 +41,19 @@ private val TAG = DocumentsStorage::class.java.simpleName
 internal class DocumentsStorage(
     private val appContext: Context,
     private val settingsManager: SettingsManager,
+    internal val safStorage: SafStorage,
 ) {
-    internal var safStorage: SafStorage? = null
-        get() {
-            if (field == null) field = settingsManager.getSafStorage()
-            return field
-        }
 
     /**
      * Attention: This context might be from a different user. Use with care.
      */
-    private val context: Context
+    private val context: Context get() = appContext.getStorageContext { safStorage.isUsb }
-        get() = appContext.getStorageContext {
-            safStorage?.isUsb == true
-        }
     private val contentResolver: ContentResolver get() = context.contentResolver
 
     internal var rootBackupDir: DocumentFile? = null
         get() = runBlocking {
             if (field == null) {
-                val parent = safStorage?.getDocumentFile(context)
+                val parent = safStorage.getDocumentFile(context)
-                    ?: return@runBlocking null
                 field = try {
                     parent.createOrGetDirectory(context, DIRECTORY_ROOT).apply {
                         // create .nomedia file to prevent Android's MediaScanner
@@ -103,13 +93,12 @@ internal class DocumentsStorage(
      * Resets this storage abstraction, forcing it to re-fetch cached values on next access.
      */
     fun reset(newToken: Long?) {
-        safStorage = null
         currentToken = newToken
         rootBackupDir = null
         currentSetDir = null
     }
 
-    fun getAuthority(): String? = safStorage?.uri?.authority
+    fun getAuthority(): String? = safStorage.uri.authority
 
     @Throws(IOException::class)
     suspend fun getSetDir(token: Long = currentToken ?: error("no token")): DocumentFile? {

app/src/main/java/com/stevesoltys/seedvault/plugins/saf/SafFactory.kt

@@ -0,0 +1,35 @@
+/*
+ * SPDX-FileCopyrightText: 2024 The Calyx Institute
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package com.stevesoltys.seedvault.plugins.saf
+
+import android.content.Context
+import android.net.Uri
+import com.stevesoltys.seedvault.crypto.KeyManager
+import com.stevesoltys.seedvault.plugins.StoragePlugin
+import com.stevesoltys.seedvault.settings.SettingsManager
+import com.stevesoltys.seedvault.storage.SeedvaultSafStoragePlugin
+
+class SafFactory(
+    private val context: Context,
+    private val keyManager: KeyManager,
+    private val settingsManager: SettingsManager,
+) {
+
+    internal fun createAppStoragePlugin(
+        safStorage: SafStorage,
+        documentsStorage: DocumentsStorage = DocumentsStorage(context, settingsManager, safStorage),
+    ): StoragePlugin<Uri> {
+        return DocumentsProviderStoragePlugin(context, documentsStorage)
+    }
+
+    internal fun createFilesStoragePlugin(
+        safStorage: SafStorage,
+        documentsStorage: DocumentsStorage = DocumentsStorage(context, settingsManager, safStorage),
+    ): org.calyxos.backup.storage.api.StoragePlugin {
+        return SeedvaultSafStoragePlugin(context, documentsStorage, keyManager)
+    }
+
+}

app/src/main/java/com/stevesoltys/seedvault/plugins/saf/SafHandler.kt

@@ -0,0 +1,95 @@
+/*
+ * SPDX-FileCopyrightText: 2024 The Calyx Institute
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package com.stevesoltys.seedvault.plugins.saf
+
+import android.content.Context
+import android.content.Context.USB_SERVICE
+import android.content.Intent.FLAG_GRANT_READ_URI_PERMISSION
+import android.content.Intent.FLAG_GRANT_WRITE_URI_PERMISSION
+import android.hardware.usb.UsbManager
+import android.net.Uri
+import android.util.Log
+import androidx.annotation.WorkerThread
+import com.stevesoltys.seedvault.R
+import com.stevesoltys.seedvault.isMassStorage
+import com.stevesoltys.seedvault.plugins.StoragePluginManager
+import com.stevesoltys.seedvault.settings.FlashDrive
+import com.stevesoltys.seedvault.settings.SettingsManager
+import com.stevesoltys.seedvault.ui.storage.StorageOption
+import java.io.IOException
+
+private const val TAG = "SafHandler"
+
+internal class SafHandler(
+    private val context: Context,
+    private val safFactory: SafFactory,
+    private val settingsManager: SettingsManager,
+    private val storagePluginManager: StoragePluginManager,
+) {
+
+    fun onConfigReceived(uri: Uri, safOption: StorageOption.SafOption): SafStorage {
+        // persist permission to access backup folder across reboots
+        val takeFlags = FLAG_GRANT_READ_URI_PERMISSION or FLAG_GRANT_WRITE_URI_PERMISSION
+        context.contentResolver.takePersistableUriPermission(uri, takeFlags)
+
+        val name = if (safOption.isInternal()) {
+            "${safOption.title} (${context.getString(R.string.settings_backup_location_internal)})"
+        } else {
+            safOption.title
+        }
+        return SafStorage(uri, name, safOption.isUsb, safOption.requiresNetwork)
+    }
+
+    /**
+     * Searches if there's really an app backup available in the given storage location.
+     * Returns true if at least one was found and false otherwise.
+     */
+    @WorkerThread
+    @Throws(IOException::class)
+    suspend fun hasAppBackup(safStorage: SafStorage): Boolean {
+        val storage = DocumentsStorage(context, settingsManager, safStorage)
+        val appPlugin = safFactory.createAppStoragePlugin(safStorage, storage)
+        val backups = appPlugin.getAvailableBackups()
+        return backups != null && backups.iterator().hasNext()
+    }
+
+    fun save(safStorage: SafStorage) {
+        settingsManager.setSafStorage(safStorage)
+
+        if (safStorage.isUsb) {
+            Log.d(TAG, "Selected storage is a removable USB device.")
+            val wasSaved = saveUsbDevice()
+            // reset stored flash drive, if we did not update it
+            if (!wasSaved) settingsManager.setFlashDrive(null)
+        } else {
+            settingsManager.setFlashDrive(null)
+        }
+        Log.d(TAG, "New storage location saved: ${safStorage.uri}")
+    }
+
+    private fun saveUsbDevice(): Boolean {
+        val manager = context.getSystemService(USB_SERVICE) as UsbManager
+        manager.deviceList.values.forEach { device ->
+            if (device.isMassStorage()) {
+                val flashDrive = FlashDrive.from(device)
+                settingsManager.setFlashDrive(flashDrive)
+                Log.d(TAG, "Saved flash drive: $flashDrive")
+                return true
+            }
+        }
+        Log.e(TAG, "No USB device found even though we were expecting one.")
+        return false
+    }
+
+    fun setPlugin(safStorage: SafStorage) {
+        val storage = DocumentsStorage(context, settingsManager, safStorage)
+        storagePluginManager.changePlugins(
+            storageProperties = safStorage,
+            appPlugin = safFactory.createAppStoragePlugin(safStorage, storage),
+            filesPlugin = safFactory.createFilesStoragePlugin(safStorage, storage),
+        )
+    }
+}

app/src/main/java/com/stevesoltys/seedvault/plugins/saf/SafStorage.kt

@@ -6,19 +6,21 @@
 package com.stevesoltys.seedvault.plugins.saf
 
 import android.content.Context
-import android.net.ConnectivityManager
-import android.net.NetworkCapabilities
 import android.net.Uri
 import androidx.annotation.WorkerThread
 import androidx.documentfile.provider.DocumentFile
+import com.stevesoltys.seedvault.plugins.StorageProperties
 
 data class SafStorage(
-    val uri: Uri,
+    override val config: Uri,
-    val name: String,
+    override val name: String,
-    val isUsb: Boolean,
+    override val isUsb: Boolean,
-    val requiresNetwork: Boolean,
+    override val requiresNetwork: Boolean,
-) {
+) : StorageProperties<Uri>() {
-    fun getDocumentFile(context: Context) = DocumentFile.fromTreeUri(context, uri)
+
+    val uri: Uri = config
+
+    fun getDocumentFile(context: Context) = DocumentFile.fromTreeUri(context, config)
         ?: throw AssertionError("Should only happen on API < 21.")
 
     /**
@@ -27,23 +29,7 @@ data class SafStorage(
      * Must be run off UI thread (ideally I/O).
      */
     @WorkerThread
-    fun isUnavailableUsb(context: Context): Boolean {
+    override fun isUnavailableUsb(context: Context): Boolean {
         return isUsb && !getDocumentFile(context).isDirectory
     }
-
-    /**
-     * Returns true if this is storage that requires network access,
-     * but it isn't available right now.
-     */
-    fun isUnavailableNetwork(context: Context, allowMetered: Boolean): Boolean {
-        return requiresNetwork && !hasUnmeteredInternet(context, allowMetered)
-    }
-
-    private fun hasUnmeteredInternet(context: Context, allowMetered: Boolean): Boolean {
-        val cm = context.getSystemService(ConnectivityManager::class.java) ?: return false
-        val isMetered = cm.isActiveNetworkMetered
-        val capabilities = cm.getNetworkCapabilities(cm.activeNetwork) ?: return false
-        return capabilities.hasCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET) &&
-            (allowMetered || !isMetered)
-    }
 }

app/src/main/java/com/stevesoltys/seedvault/plugins/webdav/WebDavModule.kt

@@ -1,17 +1,10 @@
 package com.stevesoltys.seedvault.plugins.webdav
 
-import com.stevesoltys.seedvault.plugins.LegacyStoragePlugin
 import com.stevesoltys.seedvault.plugins.StoragePlugin
-import com.stevesoltys.seedvault.plugins.saf.DocumentsProviderLegacyPlugin
-import com.stevesoltys.seedvault.plugins.saf.DocumentsStorage
 import org.koin.android.ext.koin.androidContext
 import org.koin.dsl.module
 
 val webDavModule = module {
     // TODO PluginManager should create the plugin on demand
-    single<StoragePlugin> { WebDavStoragePlugin(androidContext(), WebDavConfig("", "", "")) }
+    single<StoragePlugin<*>> { WebDavStoragePlugin(androidContext(), WebDavConfig("", "", "")) }
-
-    single { DocumentsStorage(androidContext(), get()) }
-    @Suppress("Deprecation")
-    single<LegacyStoragePlugin> { DocumentsProviderLegacyPlugin(androidContext(), get()) }
 }

app/src/main/java/com/stevesoltys/seedvault/plugins/webdav/WebDavStoragePlugin.kt

@@ -13,7 +13,6 @@ import com.stevesoltys.seedvault.plugins.chunkFolderRegex
 import com.stevesoltys.seedvault.plugins.saf.FILE_BACKUP_METADATA
 import com.stevesoltys.seedvault.plugins.saf.FILE_NO_MEDIA
 import com.stevesoltys.seedvault.plugins.tokenRegex
-import com.stevesoltys.seedvault.plugins.saf.SafStorage
 import okhttp3.HttpUrl.Companion.toHttpUrl
 import java.io.IOException
 import java.io.InputStream
@@ -25,7 +24,7 @@ internal class WebDavStoragePlugin(
     context: Context,
     webDavConfig: WebDavConfig,
     root: String = DIRECTORY_ROOT,
-) : WebDavStorage(webDavConfig, root), StoragePlugin {
+) : WebDavStorage(webDavConfig, root), StoragePlugin<WebDavConfig> {
 
     override suspend fun test(): Boolean {
         val location = baseUrl.toHttpUrl()
@@ -134,12 +133,6 @@ internal class WebDavStoragePlugin(
         }
     }
 
-    @Throws(IOException::class)
-    override suspend fun hasBackup(safStorage: SafStorage): Boolean {
-        // TODO this requires refactoring
-        return true
-    }
-
     override suspend fun getAvailableBackups(): Sequence<EncryptedMetadata>? {
         return try {
             doGetAvailableBackups()

app/src/main/java/com/stevesoltys/seedvault/restore/RestoreViewModel.kt

@@ -28,6 +28,7 @@ import com.stevesoltys.seedvault.metadata.PackageState.NO_DATA
 import com.stevesoltys.seedvault.metadata.PackageState.QUOTA_EXCEEDED
 import com.stevesoltys.seedvault.metadata.PackageState.UNKNOWN_ERROR
 import com.stevesoltys.seedvault.metadata.PackageState.WAS_STOPPED
+import com.stevesoltys.seedvault.plugins.StoragePluginManager
 import com.stevesoltys.seedvault.restore.DisplayFragment.RESTORE_APPS
 import com.stevesoltys.seedvault.restore.DisplayFragment.RESTORE_BACKUP
 import com.stevesoltys.seedvault.restore.DisplayFragment.RESTORE_FILES
@@ -81,8 +82,9 @@ internal class RestoreViewModel(
     private val restoreCoordinator: RestoreCoordinator,
     private val apkRestore: ApkRestore,
     storageBackup: StorageBackup,
+    pluginManager: StoragePluginManager,
     private val ioDispatcher: CoroutineDispatcher = Dispatchers.IO,
-) : RequireProvisioningViewModel(app, settingsManager, keyManager),
+) : RequireProvisioningViewModel(app, settingsManager, keyManager, pluginManager),
     RestorableBackupClickListener, SnapshotViewModel {
 
     override val isRestoreOperation = true

app/src/main/java/com/stevesoltys/seedvault/restore/install/ApkRestore.kt

@@ -10,6 +10,7 @@ import com.stevesoltys.seedvault.metadata.ApkSplit
 import com.stevesoltys.seedvault.metadata.PackageMetadata
 import com.stevesoltys.seedvault.plugins.LegacyStoragePlugin
 import com.stevesoltys.seedvault.plugins.StoragePlugin
+import com.stevesoltys.seedvault.plugins.StoragePluginManager
 import com.stevesoltys.seedvault.restore.RestorableBackup
 import com.stevesoltys.seedvault.restore.install.ApkInstallState.FAILED_SYSTEM_APP
 import com.stevesoltys.seedvault.restore.install.ApkInstallState.IN_PROGRESS
@@ -28,7 +29,7 @@ private val TAG = ApkRestore::class.java.simpleName
 
 internal class ApkRestore(
     private val context: Context,
-    private val storagePlugin: StoragePlugin,
+    private val pluginManager: StoragePluginManager,
     @Suppress("Deprecation")
     private val legacyStoragePlugin: LegacyStoragePlugin,
     private val crypto: Crypto,
@@ -37,6 +38,7 @@ internal class ApkRestore(
 ) {
 
     private val pm = context.packageManager
+    private val storagePlugin get() = pluginManager.appPlugin
 
     fun restore(backup: RestorableBackup) = flow {
         // we don't filter out apps without APK, so the user can manually install them
@@ -87,7 +89,7 @@ internal class ApkRestore(
         emit(installResult)
     }
 
-    @Suppress("ThrowsCount", "BlockingMethodInNonBlockingContext") // flows on Dispatcher.IO
+    @Suppress("ThrowsCount")
     @Throws(IOException::class, SecurityException::class)
     private suspend fun restore(
         collector: FlowCollector<InstallResult>,
@@ -212,7 +214,6 @@ internal class ApkRestore(
      * @return a [Pair] of the cached [File] and SHA-256 hash.
      */
     @Throws(IOException::class)
-    @Suppress("BlockingMethodInNonBlockingContext") // flows on Dispatcher.IO
     private suspend fun cacheApk(
         version: Byte,
         token: Long,

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

@@ -1,27 +0,0 @@
-package com.stevesoltys.seedvault.settings
-
-import android.content.ContentResolver
-import android.provider.Settings
-
-private val SETTING = Settings.Secure.BACKUP_MANAGER_CONSTANTS
-
-object BackupManagerSettings {
-
-    /**
-     * This clears the backup settings, so that default values will be used.
-     *
-     * Before end of 2020 (Android 11) we changed the settings in an attempt
-     * to prevent automatic backups when flash drives are not plugged in.
-     * This turned out to not work reliably, so reset to defaults again here.
-     *
-     * We can remove this code after the last users can be expected
-     * to have changed storage at least once with this code deployed.
-     */
-    fun resetDefaults(resolver: ContentResolver) {
-        if (Settings.Secure.getString(resolver, SETTING) != null) {
-            // setting this to null will cause the BackupManagerConstants to use default values
-            Settings.Secure.putString(resolver, SETTING, null)
-        }
-    }
-
-}

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

@@ -10,6 +10,7 @@ import androidx.work.ExistingPeriodicWorkPolicy.CANCEL_AND_REENQUEUE
 import androidx.work.ExistingPeriodicWorkPolicy.UPDATE
 import com.stevesoltys.seedvault.R
 import com.stevesoltys.seedvault.permitDiskReads
+import com.stevesoltys.seedvault.plugins.StoragePluginManager
 import org.koin.android.ext.android.inject
 import org.koin.androidx.viewmodel.ext.android.sharedViewModel
 
@@ -18,6 +19,7 @@ class SchedulingFragment : PreferenceFragmentCompat(),
 
     private val viewModel: SettingsViewModel by sharedViewModel()
     private val settingsManager: SettingsManager by inject()
+    private val storagePluginManager: StoragePluginManager by inject()
 
     override fun onCreatePreferences(savedInstanceState: Bundle?, rootKey: String?) {
         permitDiskReads {
@@ -29,7 +31,7 @@ class SchedulingFragment : PreferenceFragmentCompat(),
     override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
         super.onViewCreated(view, savedInstanceState)
 
-        val storage = settingsManager.getSafStorage()
+        val storage = storagePluginManager.storageProperties
         if (storage?.isUsb == true) {
             findPreference<PreferenceCategory>("scheduling_category_conditions")?.isEnabled = false
         }

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

@@ -22,7 +22,8 @@ import androidx.preference.TwoStatePreference
 import androidx.work.WorkInfo
 import com.stevesoltys.seedvault.R
 import com.stevesoltys.seedvault.permitDiskReads
-import com.stevesoltys.seedvault.plugins.saf.SafStorage
+import com.stevesoltys.seedvault.plugins.StoragePluginManager
+import com.stevesoltys.seedvault.plugins.StorageProperties
 import com.stevesoltys.seedvault.restore.RestoreActivity
 import com.stevesoltys.seedvault.ui.toRelativeTime
 import org.koin.android.ext.android.inject
@@ -34,7 +35,7 @@ private val TAG = SettingsFragment::class.java.name
 class SettingsFragment : PreferenceFragmentCompat() {
 
     private val viewModel: SettingsViewModel by sharedViewModel()
-    private val settingsManager: SettingsManager by inject()
+    private val storagePluginManager: StoragePluginManager by inject()
     private val backupManager: IBackupManager by inject()
 
     private lateinit var backup: TwoStatePreference
@@ -49,7 +50,8 @@ class SettingsFragment : PreferenceFragmentCompat() {
     private var menuBackupNow: MenuItem? = null
     private var menuRestore: MenuItem? = null
 
-    private var safStorage: SafStorage? = null
+    private val storageProperties: StorageProperties<*>?
+        get() = storagePluginManager.storageProperties
 
     override fun onCreatePreferences(savedInstanceState: Bundle?, rootKey: String?) {
         permitDiskReads {
@@ -165,7 +167,6 @@ class SettingsFragment : PreferenceFragmentCompat() {
         // we need to re-set the title when returning to this fragment
         activity?.setTitle(R.string.backup)
 
-        safStorage = settingsManager.getSafStorage()
         setBackupEnabledState()
         setBackupLocationSummary()
         setAutoRestoreState()
@@ -242,7 +243,7 @@ class SettingsFragment : PreferenceFragmentCompat() {
         activity?.contentResolver?.let {
             autoRestore.isChecked = Settings.Secure.getInt(it, BACKUP_AUTO_RESTORE, 1) == 1
         }
-        val storage = this.safStorage
+        val storage = this.storageProperties
         if (storage?.isUsb == true) {
             autoRestore.summary = getString(R.string.settings_auto_restore_summary) + "\n\n" +
                 getString(R.string.settings_auto_restore_summary_usb, storage.name)
@@ -253,7 +254,8 @@ class SettingsFragment : PreferenceFragmentCompat() {
 
     private fun setBackupLocationSummary() {
         // get name of storage location
-        backupLocation.summary = safStorage?.name ?: getString(R.string.settings_backup_location_none)
+        backupLocation.summary =
+            storageProperties?.name ?: getString(R.string.settings_backup_location_none)
     }
 
     private fun setAppBackupStatusSummary(lastBackupInMillis: Long?) {
@@ -272,7 +274,7 @@ class SettingsFragment : PreferenceFragmentCompat() {
      * says that nothing is scheduled which can happen when backup destination is on flash drive.
      */
     private fun setAppBackupSchedulingSummary(workInfo: WorkInfo?) {
-        if (safStorage?.isUsb == true) {
+        if (storageProperties?.isUsb == true) {
             backupScheduling.summary = getString(R.string.settings_backup_status_next_backup_usb)
             return
         }

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

@@ -3,15 +3,14 @@ package com.stevesoltys.seedvault.settings
 import android.content.Context
 import android.content.SharedPreferences.OnSharedPreferenceChangeListener
 import android.hardware.usb.UsbDevice
-import android.net.ConnectivityManager
-import android.net.NetworkCapabilities
 import android.net.Uri
 import androidx.annotation.UiThread
 import androidx.annotation.WorkerThread
-import androidx.documentfile.provider.DocumentFile
 import androidx.preference.PreferenceManager
 import com.stevesoltys.seedvault.getStorageContext
 import com.stevesoltys.seedvault.permitDiskReads
+import com.stevesoltys.seedvault.plugins.StoragePlugin
+import com.stevesoltys.seedvault.plugins.saf.DocumentsProviderStoragePlugin
 import com.stevesoltys.seedvault.plugins.saf.SafStorage
 import com.stevesoltys.seedvault.transport.backup.BackupCoordinator
 import java.util.concurrent.ConcurrentSkipListSet
@@ -23,6 +22,12 @@ internal const val PREF_KEY_SCHED_FREQ = "scheduling_frequency"
 internal const val PREF_KEY_SCHED_METERED = "scheduling_metered"
 internal const val PREF_KEY_SCHED_CHARGING = "scheduling_charging"
 
+private const val PREF_KEY_STORAGE_PLUGIN = "storagePlugin"
+
+internal enum class StoragePluginEnum { // don't rename, will break existing installs
+    SAF,
+}
+
 private const val PREF_KEY_STORAGE_URI = "storageUri"
 private const val PREF_KEY_STORAGE_NAME = "storageName"
 private const val PREF_KEY_STORAGE_IS_USB = "storageIsUsb"
@@ -90,6 +95,25 @@ class SettingsManager(private val context: Context) {
     }
 
     // FIXME SafStorage is currently plugin specific and not generic
+    internal val storagePluginType: StoragePluginEnum?
+        get() = prefs.getString(PREF_KEY_STORAGE_PLUGIN, StoragePluginEnum.SAF.name)?.let {
+            try {
+                StoragePluginEnum.valueOf(it)
+            } catch (e: IllegalArgumentException) {
+                null
+            }
+        }
+
+    fun setStoragePlugin(plugin: StoragePlugin<*>) {
+        val value = when (plugin) {
+            is DocumentsProviderStoragePlugin -> StoragePluginEnum.SAF
+            else -> error("Unsupported plugin: ${plugin::class.java.simpleName}")
+        }.name
+        prefs.edit()
+            .putString(PREF_KEY_STORAGE_PLUGIN, value)
+            .apply()
+    }
+
     fun setSafStorage(safStorage: SafStorage) {
         prefs.edit()
             .putString(PREF_KEY_STORAGE_URI, safStorage.uri.toString())
@@ -196,42 +220,6 @@ class SettingsManager(private val context: Context) {
     }
 }
 
-data class Storage(
-    val uri: Uri,
-    val name: String,
-    val isUsb: Boolean,
-    val requiresNetwork: Boolean,
-) {
-    fun getDocumentFile(context: Context) = DocumentFile.fromTreeUri(context, uri)
-        ?: throw AssertionError("Should only happen on API < 21.")
-
-    /**
-     * Returns true if this is USB storage that is not available, false otherwise.
-     *
-     * Must be run off UI thread (ideally I/O).
-     */
-    @WorkerThread
-    fun isUnavailableUsb(context: Context): Boolean {
-        return isUsb && !getDocumentFile(context).isDirectory
-    }
-
-    /**
-     * Returns true if this is storage that requires network access,
-     * but it isn't available right now.
-     */
-    fun isUnavailableNetwork(context: Context, allowMetered: Boolean): Boolean {
-        return requiresNetwork && !hasUnmeteredInternet(context, allowMetered)
-    }
-
-    private fun hasUnmeteredInternet(context: Context, allowMetered: Boolean): Boolean {
-        val cm = context.getSystemService(ConnectivityManager::class.java) ?: return false
-        val isMetered = cm.isActiveNetworkMetered
-        val capabilities = cm.getNetworkCapabilities(cm.activeNetwork) ?: return false
-        return capabilities.hasCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET) &&
-            (allowMetered || !isMetered)
-    }
-}
-
 data class FlashDrive(
     val name: String,
     val serialNumber: String?,

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

@@ -34,6 +34,8 @@ import com.stevesoltys.seedvault.R
 import com.stevesoltys.seedvault.crypto.KeyManager
 import com.stevesoltys.seedvault.metadata.MetadataManager
 import com.stevesoltys.seedvault.permitDiskReads
+import com.stevesoltys.seedvault.plugins.StoragePluginManager
+import com.stevesoltys.seedvault.plugins.saf.SafStorage
 import com.stevesoltys.seedvault.storage.StorageBackupJobService
 import com.stevesoltys.seedvault.storage.StorageBackupService
 import com.stevesoltys.seedvault.storage.StorageBackupService.Companion.EXTRA_START_APP_BACKUP
@@ -59,12 +61,13 @@ internal class SettingsViewModel(
     app: Application,
     settingsManager: SettingsManager,
     keyManager: KeyManager,
+    private val pluginManager: StoragePluginManager,
     private val metadataManager: MetadataManager,
     private val appListRetriever: AppListRetriever,
     private val storageBackup: StorageBackup,
     private val backupManager: IBackupManager,
     private val backupInitializer: BackupInitializer,
-) : RequireProvisioningViewModel(app, settingsManager, keyManager) {
+) : RequireProvisioningViewModel(app, settingsManager, keyManager, pluginManager) {
 
     private val contentResolver = app.contentResolver
     private val connectivityManager: ConnectivityManager? =
@@ -131,9 +134,9 @@ internal class SettingsViewModel(
     }
 
     override fun onStorageLocationChanged() {
-        val storage = settingsManager.getSafStorage() ?: return
+        val storage = pluginManager.storageProperties ?: return
 
-        Log.i(TAG, "onStorageLocationChanged (isUsb: ${storage.isUsb}")
+        Log.i(TAG, "onStorageLocationChanged (isUsb: ${storage.isUsb})")
         if (storage.isUsb) {
             // disable storage backup if new storage is on USB
             cancelAppBackup()
@@ -149,24 +152,27 @@ internal class SettingsViewModel(
 
     fun onWorkerStateChanged() {
         viewModelScope.launch(Dispatchers.IO) {
-            val canDo = settingsManager.canDoBackupNow() &&
+            val canDo = pluginManager.canDoBackupNow() &&
                 appBackupWorkInfo.value?.state != WorkInfo.State.RUNNING
             mBackupPossible.postValue(canDo)
         }
     }
 
     private fun onStoragePropertiesChanged() {
-        val storage = settingsManager.getSafStorage() ?: return
+        val storage = pluginManager.storageProperties ?: return
 
         Log.d(TAG, "onStoragePropertiesChanged")
-        // register storage observer
+        if (storage is SafStorage) {
-        try {
+            // register storage observer
-            contentResolver.unregisterContentObserver(storageObserver)
+            try {
-            contentResolver.registerContentObserver(storage.uri, false, storageObserver)
+                contentResolver.unregisterContentObserver(storageObserver)
-        } catch (e: SecurityException) {
+                contentResolver.registerContentObserver(storage.uri, false, storageObserver)
-            // This can happen if the app providing the storage was uninstalled.
+            } catch (e: SecurityException) {
-            // validLocationIsSet() gets called elsewhere and prompts for a new storage location.
+                // This can happen if the app providing the storage was uninstalled.
-            Log.e(TAG, "Error registering content observer for ${storage.uri}", e)
+                // validLocationIsSet() gets called elsewhere
+                // and prompts for a new storage location.
+                Log.e(TAG, "Error registering content observer for ${storage.uri}", e)
+            }
         }
 
         // register network observer if needed
@@ -301,7 +307,7 @@ internal class SettingsViewModel(
         }
     }
 
-    fun cancelAppBackup() {
+    private fun cancelAppBackup() {
         AppBackupWorker.unschedule(app)
     }
 

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

@@ -16,12 +16,8 @@ internal class SeedvaultSafStoragePlugin(
     /**
      * Attention: This context might be from a different user. Use with care.
      */
-    override val context: Context
+    override val context: Context get() = appContext.getStorageContext { storage.safStorage.isUsb }
-        get() = appContext.getStorageContext {
+    override val root: DocumentFile get() = storage.rootBackupDir ?: error("No storage set")
-            storage.safStorage?.isUsb == true
-        }
-    override val root: DocumentFile
-        get() = storage.rootBackupDir ?: error("No storage set")
 
     override fun getMasterKey(): SecretKey = keyManager.getMainKey()
     override fun hasMasterKey(): Boolean = keyManager.hasMainKey()

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

@@ -1,7 +1,7 @@
 package com.stevesoltys.seedvault.storage
 
 import android.content.Intent
-import com.stevesoltys.seedvault.settings.SettingsManager
+import com.stevesoltys.seedvault.plugins.StoragePluginManager
 import com.stevesoltys.seedvault.worker.AppBackupWorker
 import org.calyxos.backup.storage.api.BackupObserver
 import org.calyxos.backup.storage.api.RestoreObserver
@@ -34,7 +34,7 @@ internal class StorageBackupService : BackupService() {
     }
 
     override val storageBackup: StorageBackup by inject()
-    private val settingsManager: SettingsManager by inject()
+    private val storagePluginManager: StoragePluginManager by inject()
 
     // use lazy delegate because context isn't available during construction time
     override val backupObserver: BackupObserver by lazy {
@@ -43,7 +43,7 @@ internal class StorageBackupService : BackupService() {
 
     override fun onBackupFinished(intent: Intent, success: Boolean) {
         if (intent.getBooleanExtra(EXTRA_START_APP_BACKUP, false)) {
-            val isUsb = settingsManager.getSafStorage()?.isUsb ?: false
+            val isUsb = storagePluginManager.storageProperties?.isUsb ?: false
             AppBackupWorker.scheduleNow(applicationContext, reschedule = !isUsb)
         }
     }

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

@@ -1,10 +1,9 @@
 package com.stevesoltys.seedvault.storage
 
+import com.stevesoltys.seedvault.plugins.StoragePluginManager
 import org.calyxos.backup.storage.api.StorageBackup
-import org.calyxos.backup.storage.api.StoragePlugin
 import org.koin.dsl.module
 
 val storageModule = module {
-    single<StoragePlugin> { SeedvaultSafStoragePlugin(get(), get(), get()) }
+    single { StorageBackup(get(), { get<StoragePluginManager>().filesPlugin }) }
-    single { StorageBackup(get(), get()) }
 }

app/src/main/java/com/stevesoltys/seedvault/transport/backup/BackupCoordinator.kt

@@ -25,6 +25,7 @@ import com.stevesoltys.seedvault.metadata.PackageState.NO_DATA
 import com.stevesoltys.seedvault.metadata.PackageState.QUOTA_EXCEEDED
 import com.stevesoltys.seedvault.metadata.PackageState.UNKNOWN_ERROR
 import com.stevesoltys.seedvault.plugins.StoragePlugin
+import com.stevesoltys.seedvault.plugins.StoragePluginManager
 import com.stevesoltys.seedvault.plugins.saf.FILE_BACKUP_METADATA
 import com.stevesoltys.seedvault.settings.SettingsManager
 import com.stevesoltys.seedvault.ui.notification.BackupNotificationManager
@@ -54,11 +55,10 @@ private class CoordinatorState(
  * @author Steve Soltys
  * @author Torsten Grote
  */
-@WorkerThread // entire class should always be accessed from a worker thread, so blocking is ok
+@WorkerThread
-@Suppress("BlockingMethodInNonBlockingContext")
 internal class BackupCoordinator(
     private val context: Context,
-    private val plugin: StoragePlugin,
+    private val pluginManager: StoragePluginManager,
     private val kv: KVBackup,
     private val full: FullBackup,
     private val clock: Clock,
@@ -68,6 +68,7 @@ internal class BackupCoordinator(
     private val nm: BackupNotificationManager,
 ) {
 
+    private val plugin get() = pluginManager.appPlugin
     private val state = CoordinatorState(
         calledInitialize = false,
         calledClearBackupData = false,
@@ -126,7 +127,7 @@ internal class BackupCoordinator(
     } catch (e: Exception) {
         Log.e(TAG, "Error initializing device", e)
         // Show error notification if we needed init or were ready for backups
-        if (metadataManager.requiresInit || settingsManager.canDoBackupNow()) nm.onBackupError()
+        if (metadataManager.requiresInit || pluginManager.canDoBackupNow()) nm.onBackupError()
         TRANSPORT_ERROR
     }
 
@@ -354,7 +355,7 @@ internal class BackupCoordinator(
             if (result == TRANSPORT_OK) {
                 val isNormalBackup = packageName != MAGIC_PACKAGE_MANAGER
                 // call onPackageBackedUp for @pm@ only if we can do backups right now
-                if (isNormalBackup || settingsManager.canDoBackupNow()) {
+                if (isNormalBackup || pluginManager.canDoBackupNow()) {
                     try {
                         onPackageBackedUp(packageInfo, BackupType.KV, size)
                     } catch (e: Exception) {
@@ -411,7 +412,7 @@ internal class BackupCoordinator(
         val longBackoff = DAYS.toMillis(30)
 
         // back off if there's no storage set
-        val storage = settingsManager.getSafStorage() ?: return longBackoff
+        val storage = pluginManager.storageProperties ?: return longBackoff
         return when {
             // back off if storage is removable and not available right now
             storage.isUnavailableUsb(context) -> longBackoff
@@ -425,7 +426,9 @@ internal class BackupCoordinator(
         }
     }
 
-    private suspend fun StoragePlugin.getMetadataOutputStream(token: Long? = null): OutputStream {
+    private suspend fun StoragePlugin<*>.getMetadataOutputStream(
+        token: Long? = null,
+    ): OutputStream {
         val t = token ?: settingsManager.getToken() ?: throw IOException("no current token")
         return getOutputStream(t, FILE_BACKUP_METADATA)
     }

app/src/main/java/com/stevesoltys/seedvault/transport/backup/BackupModule.kt

@@ -11,38 +11,38 @@ val backupModule = module {
             context = androidContext(),
             backupManager = get(),
             settingsManager = get(),
-            plugin = get()
+            pluginManager = get(),
         )
     }
     single<KvDbManager> { KvDbManagerImpl(androidContext()) }
     single {
         KVBackup(
-            plugin = get(),
+            pluginManager = get(),
             settingsManager = get(),
             inputFactory = get(),
             crypto = get(),
-            dbManager = get()
+            dbManager = get(),
         )
     }
     single {
         FullBackup(
-            plugin = get(),
+            pluginManager = get(),
             settingsManager = get(),
             inputFactory = get(),
-            crypto = get()
+            crypto = get(),
         )
     }
     single {
         BackupCoordinator(
             context = androidContext(),
-            plugin = get(),
+            pluginManager = get(),
             kv = get(),
             full = get(),
             clock = get(),
             packageService = get(),
             metadataManager = get(),
             settingsManager = get(),
-            nm = get()
+            nm = get(),
         )
     }
 }

app/src/main/java/com/stevesoltys/seedvault/transport/backup/FullBackup.kt

@@ -11,7 +11,7 @@ import android.util.Log
 import com.stevesoltys.seedvault.crypto.Crypto
 import com.stevesoltys.seedvault.header.VERSION
 import com.stevesoltys.seedvault.header.getADForFull
-import com.stevesoltys.seedvault.plugins.StoragePlugin
+import com.stevesoltys.seedvault.plugins.StoragePluginManager
 import com.stevesoltys.seedvault.settings.SettingsManager
 import libcore.io.IoUtils.closeQuietly
 import java.io.EOFException
@@ -39,12 +39,13 @@ private val TAG = FullBackup::class.java.simpleName
 
 @Suppress("BlockingMethodInNonBlockingContext")
 internal class FullBackup(
-    private val plugin: StoragePlugin,
+    private val pluginManager: StoragePluginManager,
     private val settingsManager: SettingsManager,
     private val inputFactory: InputFactory,
     private val crypto: Crypto,
 ) {
 
+    private val plugin get() = pluginManager.appPlugin
     private var state: FullBackupState? = null
 
     fun hasState() = state != null

app/src/main/java/com/stevesoltys/seedvault/transport/backup/KVBackup.kt

@@ -13,7 +13,7 @@ import com.stevesoltys.seedvault.MAGIC_PACKAGE_MANAGER
 import com.stevesoltys.seedvault.crypto.Crypto
 import com.stevesoltys.seedvault.header.VERSION
 import com.stevesoltys.seedvault.header.getADForKV
-import com.stevesoltys.seedvault.plugins.StoragePlugin
+import com.stevesoltys.seedvault.plugins.StoragePluginManager
 import com.stevesoltys.seedvault.settings.SettingsManager
 import java.io.IOException
 import java.util.zip.GZIPOutputStream
@@ -31,15 +31,15 @@ const val DEFAULT_QUOTA_KEY_VALUE_BACKUP = (2 * (5 * 1024 * 1024)).toLong()
 
 private val TAG = KVBackup::class.java.simpleName
 
-@Suppress("BlockingMethodInNonBlockingContext")
 internal class KVBackup(
-    private val plugin: StoragePlugin,
+    private val pluginManager: StoragePluginManager,
     private val settingsManager: SettingsManager,
     private val inputFactory: InputFactory,
     private val crypto: Crypto,
     private val dbManager: KvDbManager,
 ) {
 
+    private val plugin get() = pluginManager.appPlugin
     private var state: KVBackupState? = null
 
     fun hasState() = state != null
@@ -138,7 +138,7 @@ internal class KVBackup(
                 // K/V backups (typically starting with package manager metadata - @pm@)
                 // are scheduled with JobInfo.Builder#setOverrideDeadline()
                 // and thus do not respect backoff.
-                settingsManager.canDoBackupNow()
+                pluginManager.canDoBackupNow()
             } else {
                 // all other packages always need upload
                 true

app/src/main/java/com/stevesoltys/seedvault/transport/backup/PackageService.kt

@@ -18,6 +18,7 @@ import android.util.Log.INFO
 import androidx.annotation.WorkerThread
 import com.stevesoltys.seedvault.MAGIC_PACKAGE_MANAGER
 import com.stevesoltys.seedvault.plugins.StoragePlugin
+import com.stevesoltys.seedvault.plugins.StoragePluginManager
 import com.stevesoltys.seedvault.settings.SettingsManager
 
 private val TAG = PackageService::class.java.simpleName
@@ -32,11 +33,12 @@ internal class PackageService(
     private val context: Context,
     private val backupManager: IBackupManager,
     private val settingsManager: SettingsManager,
-    private val plugin: StoragePlugin,
+    private val pluginManager: StoragePluginManager,
 ) {
 
     private val packageManager: PackageManager = context.packageManager
     private val myUserId = UserHandle.myUserId()
+    private val plugin: StoragePlugin<*> get() = pluginManager.appPlugin
 
     val eligiblePackages: List<String>
         @WorkerThread

app/src/main/java/com/stevesoltys/seedvault/transport/restore/FullRestore.kt

@@ -13,7 +13,7 @@ import com.stevesoltys.seedvault.header.MAX_SEGMENT_LENGTH
 import com.stevesoltys.seedvault.header.UnsupportedVersionException
 import com.stevesoltys.seedvault.header.getADForFull
 import com.stevesoltys.seedvault.plugins.LegacyStoragePlugin
-import com.stevesoltys.seedvault.plugins.StoragePlugin
+import com.stevesoltys.seedvault.plugins.StoragePluginManager
 import libcore.io.IoUtils.closeQuietly
 import java.io.EOFException
 import java.io.IOException
@@ -32,9 +32,8 @@ private class FullRestoreState(
 
 private val TAG = FullRestore::class.java.simpleName
 
-@Suppress("BlockingMethodInNonBlockingContext")
 internal class FullRestore(
-    private val plugin: StoragePlugin,
+    private val pluginManager: StoragePluginManager,
     @Suppress("Deprecation")
     private val legacyPlugin: LegacyStoragePlugin,
     private val outputFactory: OutputFactory,
@@ -42,6 +41,7 @@ internal class FullRestore(
     private val crypto: Crypto,
 ) {
 
+    private val plugin get() = pluginManager.appPlugin
     private var state: FullRestoreState? = null
 
     fun hasState() = state != null

app/src/main/java/com/stevesoltys/seedvault/transport/restore/KVRestore.kt

@@ -16,13 +16,12 @@ import com.stevesoltys.seedvault.header.UnsupportedVersionException
 import com.stevesoltys.seedvault.header.VERSION
 import com.stevesoltys.seedvault.header.getADForKV
 import com.stevesoltys.seedvault.plugins.LegacyStoragePlugin
-import com.stevesoltys.seedvault.plugins.StoragePlugin
+import com.stevesoltys.seedvault.plugins.StoragePluginManager
 import com.stevesoltys.seedvault.transport.backup.KVDb
 import com.stevesoltys.seedvault.transport.backup.KvDbManager
 import libcore.io.IoUtils.closeQuietly
 import java.io.IOException
 import java.security.GeneralSecurityException
-import java.util.ArrayList
 import java.util.zip.GZIPInputStream
 import javax.crypto.AEADBadTagException
 
@@ -39,9 +38,8 @@ private class KVRestoreState(
 
 private val TAG = KVRestore::class.java.simpleName
 
-@Suppress("BlockingMethodInNonBlockingContext")
 internal class KVRestore(
-    private val plugin: StoragePlugin,
+    private val pluginManager: StoragePluginManager,
     @Suppress("Deprecation")
     private val legacyPlugin: LegacyStoragePlugin,
     private val outputFactory: OutputFactory,
@@ -50,6 +48,7 @@ internal class KVRestore(
     private val dbManager: KvDbManager,
 ) {
 
+    private val plugin get() = pluginManager.appPlugin
     private var state: KVRestoreState? = null
 
     /**

app/src/main/java/com/stevesoltys/seedvault/transport/restore/RestoreCoordinator.kt

@@ -21,6 +21,7 @@ import com.stevesoltys.seedvault.metadata.DecryptionFailedException
 import com.stevesoltys.seedvault.metadata.MetadataManager
 import com.stevesoltys.seedvault.metadata.MetadataReader
 import com.stevesoltys.seedvault.plugins.StoragePlugin
+import com.stevesoltys.seedvault.plugins.StoragePluginManager
 import com.stevesoltys.seedvault.settings.SettingsManager
 import com.stevesoltys.seedvault.transport.D2D_TRANSPORT_FLAGS
 import com.stevesoltys.seedvault.transport.DEFAULT_TRANSPORT_FLAGS
@@ -49,19 +50,19 @@ private data class RestoreCoordinatorState(
 
 private val TAG = RestoreCoordinator::class.java.simpleName
 
-@Suppress("BlockingMethodInNonBlockingContext")
 internal class RestoreCoordinator(
     private val context: Context,
     private val crypto: Crypto,
     private val settingsManager: SettingsManager,
     private val metadataManager: MetadataManager,
     private val notificationManager: BackupNotificationManager,
-    private val plugin: StoragePlugin,
+    private val pluginManager: StoragePluginManager,
     private val kv: KVRestore,
     private val full: FullRestore,
     private val metadataReader: MetadataReader,
 ) {
 
+    private val plugin: StoragePlugin<*> get() = pluginManager.appPlugin
     private var state: RestoreCoordinatorState? = null
     private var backupMetadata: BackupMetadata? = null
     private val failedPackages = ArrayList<String>()
@@ -169,7 +170,7 @@ internal class RestoreCoordinator(
                     // check if we even have a backup of that app
                     if (metadataManager.getPackageMetadata(pmPackageName) != null) {
                         // remind user to plug in storage device
-                        val storageName = settingsManager.getSafStorage()?.name
+                        val storageName = pluginManager.storageProperties?.name
                             ?: context.getString(R.string.settings_backup_location_none)
                         notificationManager.onRemovableStorageNotAvailableForRestore(
                             pmPackageName,
@@ -363,9 +364,8 @@ internal class RestoreCoordinator(
 
     fun isFailedPackage(packageName: String) = packageName in failedPackages
 
-    // TODO this is plugin specific, needs to be factored out when supporting different plugins
     private fun isStorageRemovableAndNotAvailable(): Boolean {
-        val storage = settingsManager.getSafStorage() ?: return false
+        val storage = pluginManager.storageProperties ?: return false
         return storage.isUnavailableUsb(context)
     }
 

app/src/main/java/com/stevesoltys/seedvault/ui/RequireProvisioningViewModel.kt

@@ -3,13 +3,14 @@ package com.stevesoltys.seedvault.ui
 import android.app.Application
 import androidx.lifecycle.AndroidViewModel
 import com.stevesoltys.seedvault.crypto.KeyManager
+import com.stevesoltys.seedvault.plugins.StoragePluginManager
 import com.stevesoltys.seedvault.settings.SettingsManager
-import com.stevesoltys.seedvault.ui.storage.StorageViewModel
 
 abstract class RequireProvisioningViewModel(
     protected val app: Application,
     protected val settingsManager: SettingsManager,
     protected val keyManager: KeyManager,
+    private val pluginManager: StoragePluginManager,
 ) : AndroidViewModel(app) {
 
     abstract val isRestoreOperation: Boolean
@@ -18,7 +19,7 @@ abstract class RequireProvisioningViewModel(
     internal val chooseBackupLocation: LiveEvent<Boolean> get() = mChooseBackupLocation
     internal fun chooseBackupLocation() = mChooseBackupLocation.setEvent(true)
 
-    internal fun validLocationIsSet() = StorageViewModel.validLocationIsSet(app, settingsManager)
+    internal fun validLocationIsSet() = pluginManager.isValidAppPluginSet()
 
     internal fun recoveryCodeIsSet() = keyManager.hasBackupKey()
 

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

@@ -3,11 +3,13 @@ package com.stevesoltys.seedvault.ui.storage
 import android.app.Application
 import android.app.backup.IBackupManager
 import android.app.job.JobInfo
-import android.net.Uri
 import android.util.Log
 import androidx.lifecycle.viewModelScope
 import androidx.work.ExistingPeriodicWorkPolicy.CANCEL_AND_REENQUEUE
 import com.stevesoltys.seedvault.R
+import com.stevesoltys.seedvault.plugins.StoragePluginManager
+import com.stevesoltys.seedvault.plugins.saf.SafHandler
+import com.stevesoltys.seedvault.plugins.saf.SafStorage
 import com.stevesoltys.seedvault.settings.SettingsManager
 import com.stevesoltys.seedvault.storage.StorageBackupJobService
 import com.stevesoltys.seedvault.transport.backup.BackupInitializer
@@ -26,14 +28,17 @@ internal class BackupStorageViewModel(
     private val backupManager: IBackupManager,
     private val backupInitializer: BackupInitializer,
     private val storageBackup: StorageBackup,
+    safHandler: SafHandler,
     settingsManager: SettingsManager,
-) : StorageViewModel(app, settingsManager) {
+    storagePluginManager: StoragePluginManager,
+) : StorageViewModel(app, safHandler, settingsManager, storagePluginManager) {
 
     override val isRestoreOperation = false
 
-    override fun onSafUriSet(uri: Uri) {
+    override fun onSafUriSet(safStorage: SafStorage) {
-        val isUsb = saveStorage(uri)
+        safHandler.save(safStorage)
-        if (isUsb) {
+        safHandler.setPlugin(safStorage)
+        if (safStorage.isUsb) {
             // disable storage backup if new storage is on USB
             cancelBackupWorkers()
         } else {
@@ -41,12 +46,16 @@ internal class BackupStorageViewModel(
             // also to update the network requirement of the new storage
             scheduleBackupWorkers()
         }
+        onStorageLocationSet(safStorage.isUsb)
+    }
+
+    private fun onStorageLocationSet(isUsb: Boolean) {
         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.init()
             try {
+                // remove old storage snapshots and clear cache
+                // TODO For SAF, this also does create all 255 chunk folders which takes time
+                //  pass a flag to getCurrentBackupSnapshots() to not create missing folders?
+                storageBackup.init()
                 // initialize the new location (if backups are enabled)
                 if (backupManager.isBackupEnabled) {
                     val onError = {
@@ -74,7 +83,7 @@ internal class BackupStorageViewModel(
     }
 
     private fun scheduleBackupWorkers() {
-        val storage = settingsManager.getSafStorage() ?: error("no storage available")
+        val storage = storagePluginManager.storageProperties ?: error("no storage available")
         if (!storage.isUsb) {
             if (backupManager.isBackupEnabled) {
                 AppBackupWorker.schedule(app, settingsManager, CANCEL_AND_REENQUEUE)

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

@@ -1,12 +1,13 @@
 package com.stevesoltys.seedvault.ui.storage
 
 import android.app.Application
-import android.net.Uri
 import android.util.Log
 import androidx.lifecycle.viewModelScope
 import com.stevesoltys.seedvault.R
-import com.stevesoltys.seedvault.plugins.StoragePlugin
+import com.stevesoltys.seedvault.plugins.StoragePluginManager
 import com.stevesoltys.seedvault.plugins.saf.DIRECTORY_ROOT
+import com.stevesoltys.seedvault.plugins.saf.SafHandler
+import com.stevesoltys.seedvault.plugins.saf.SafStorage
 import com.stevesoltys.seedvault.settings.SettingsManager
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.launch
@@ -16,26 +17,27 @@ private val TAG = RestoreStorageViewModel::class.java.simpleName
 
 internal class RestoreStorageViewModel(
     private val app: Application,
-    private val storagePlugin: StoragePlugin,
+    safHandler: SafHandler,
     settingsManager: SettingsManager,
-) : StorageViewModel(app, settingsManager) {
+    storagePluginManager: StoragePluginManager,
+) : StorageViewModel(app, safHandler, settingsManager, storagePluginManager) {
 
     override val isRestoreOperation = true
 
-    override fun onSafUriSet(uri: Uri) {
+    override fun onSafUriSet(safStorage: SafStorage) {
         viewModelScope.launch(Dispatchers.IO) {
-            val storage = createStorage(uri)
             val hasBackup = try {
-                storagePlugin.hasBackup(storage)
+                safHandler.hasAppBackup(safStorage)
             } catch (e: IOException) {
-                Log.e(TAG, "Error reading URI: $uri", e)
+                Log.e(TAG, "Error reading URI: ${safStorage.uri}", e)
                 false
             }
             if (hasBackup) {
-                saveStorage(storage)
+                safHandler.save(safStorage)
+                safHandler.setPlugin(safStorage)
                 mLocationChecked.postEvent(LocationResult())
             } else {
-                Log.w(TAG, "Location was rejected: $uri")
+                Log.w(TAG, "Location was rejected: ${safStorage.uri}")
 
                 // notify the UI that the location was invalid
                 val errorMsg =
@@ -44,5 +46,4 @@ internal class RestoreStorageViewModel(
             }
         }
     }
-
 }

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

@@ -62,9 +62,7 @@ internal class StorageOptionFetcher(private val context: Context, private val is
     internal fun getRemovableStorageListener() = listener
 
     internal fun getStorageOptions(): List<StorageOption> {
-        val roots = ArrayList<StorageOption>().apply {
+        val roots = ArrayList<StorageOption>()
-            add(WebDavOption(context))
-        }
         val intent = Intent(PROVIDER_INTERFACE)
         val providers = packageManager.queryIntentContentProviders(intent, 0)
         for (info in providers) {

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

@@ -2,23 +2,15 @@ package com.stevesoltys.seedvault.ui.storage
 
 import android.annotation.UiThread
 import android.app.Application
-import android.content.Context
-import android.content.Context.USB_SERVICE
-import android.content.Intent.FLAG_GRANT_READ_URI_PERMISSION
-import android.content.Intent.FLAG_GRANT_WRITE_URI_PERMISSION
-import android.hardware.usb.UsbManager
 import android.net.Uri
-import android.util.Log
 import androidx.lifecycle.AndroidViewModel
 import androidx.lifecycle.LiveData
 import androidx.lifecycle.MutableLiveData
 import androidx.lifecycle.viewModelScope
 import com.stevesoltys.seedvault.R
-import com.stevesoltys.seedvault.isMassStorage
+import com.stevesoltys.seedvault.plugins.StoragePluginManager
-import com.stevesoltys.seedvault.permitDiskReads
+import com.stevesoltys.seedvault.plugins.saf.SafHandler
 import com.stevesoltys.seedvault.plugins.saf.SafStorage
-import com.stevesoltys.seedvault.settings.BackupManagerSettings
-import com.stevesoltys.seedvault.settings.FlashDrive
 import com.stevesoltys.seedvault.settings.SettingsManager
 import com.stevesoltys.seedvault.ui.LiveEvent
 import com.stevesoltys.seedvault.ui.MutableLiveEvent
@@ -26,11 +18,11 @@ import com.stevesoltys.seedvault.ui.storage.StorageOption.SafOption
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.launch
 
-private val TAG = StorageViewModel::class.java.simpleName
-
 internal abstract class StorageViewModel(
     private val app: Application,
+    protected val safHandler: SafHandler,
     protected val settingsManager: SettingsManager,
+    protected val storagePluginManager: StoragePluginManager,
 ) : AndroidViewModel(app), RemovableStorageListener {
 
     private val mStorageOptions = MutableLiveData<List<StorageOption>>()
@@ -47,22 +39,9 @@ internal abstract class StorageViewModel(
 
     internal var isSetupWizard: Boolean = false
     internal val hasStorageSet: Boolean
-        get() = settingsManager.getSafStorage() != null
+        get() = storagePluginManager.storageProperties != null
     abstract val isRestoreOperation: Boolean
 
-    companion object {
-        internal fun validLocationIsSet(
-            context: Context,
-            settingsManager: SettingsManager,
-        ): Boolean {
-            val storage = settingsManager.getSafStorage() ?: return false
-            if (storage.isUsb) return true
-            return permitDiskReads {
-                storage.getDocumentFile(context).isDirectory
-            }
-        }
-    }
-
     internal fun loadStorageRoots() {
         if (storageOptionFetcher.getRemovableStorageListener() == null) {
             storageOptionFetcher.setRemovableStorageListener(this)
@@ -74,6 +53,10 @@ internal abstract class StorageViewModel(
 
     override fun onStorageChanged() = loadStorageRoots()
 
+    /**
+     * Remembers that the user chose SAF.
+     * Usually followed by a call of [onUriPermissionResultReceived].
+     */
     fun onSafOptionChosen(option: SafOption) {
         safOption = option
     }
@@ -84,71 +67,18 @@ internal abstract class StorageViewModel(
             mLocationChecked.setEvent(LocationResult(msg))
             return
         }
+        require(safOption?.uri == uri) { "URIs differ: ${safOption?.uri} != $uri" }
+
+        val root = safOption ?: throw IllegalStateException("no storage root")
+        val safStorage = safHandler.onConfigReceived(uri, root)
 
         // inform UI that a location has been successfully selected
         mLocationSet.setEvent(true)
 
-        // persist permission to access backup folder across reboots
+        onSafUriSet(safStorage)
-        val takeFlags = FLAG_GRANT_READ_URI_PERMISSION or FLAG_GRANT_WRITE_URI_PERMISSION
-        app.contentResolver.takePersistableUriPermission(uri, takeFlags)
-
-        onSafUriSet(uri)
     }
 
-    /**
+    abstract fun onSafUriSet(safStorage: SafStorage)
-     * Saves the storage behind the given [Uri] (and saved [safOption]).
-     *
-     * @return true if the storage is a USB flash drive, false otherwise.
-     */
-    protected fun saveStorage(uri: Uri): Boolean {
-        // store backup storage location in settings
-        val storage = createStorage(uri)
-        return saveStorage(storage)
-    }
-
-    protected fun createStorage(uri: Uri): SafStorage {
-        val root = safOption ?: throw IllegalStateException("no storage root")
-        val name = if (root.isInternal()) {
-            "${root.title} (${app.getString(R.string.settings_backup_location_internal)})"
-        } else {
-            root.title
-        }
-        return SafStorage(uri, name, root.isUsb, root.requiresNetwork)
-    }
-
-    protected fun saveStorage(safStorage: SafStorage): Boolean {
-        settingsManager.setSafStorage(safStorage)
-
-        if (safStorage.isUsb) {
-            Log.d(TAG, "Selected storage is a removable USB device.")
-            val wasSaved = saveUsbDevice()
-            // reset stored flash drive, if we did not update it
-            if (!wasSaved) settingsManager.setFlashDrive(null)
-        } else {
-            settingsManager.setFlashDrive(null)
-        }
-        BackupManagerSettings.resetDefaults(app.contentResolver)
-
-        Log.d(TAG, "New storage location saved: ${safStorage.uri}")
-
-        return safStorage.isUsb
-    }
-
-    private fun saveUsbDevice(): Boolean {
-        val manager = app.getSystemService(USB_SERVICE) as UsbManager
-        manager.deviceList.values.forEach { device ->
-            if (device.isMassStorage()) {
-                val flashDrive = FlashDrive.from(device)
-                settingsManager.setFlashDrive(flashDrive)
-                Log.d(TAG, "Saved flash drive: $flashDrive")
-                return true
-            }
-        }
-        Log.e(TAG, "No USB device found even though we were expecting one.")
-        return false
-    }
-
-    abstract fun onSafUriSet(uri: Uri)
 
     override fun onCleared() {
         storageOptionFetcher.setRemovableStorageListener(null)

app/src/main/java/com/stevesoltys/seedvault/worker/ApkBackup.kt

@@ -30,7 +30,6 @@ import java.security.MessageDigest
 
 private val TAG = ApkBackup::class.java.simpleName
 
-@Suppress("BlockingMethodInNonBlockingContext")
 internal class ApkBackup(
     private val pm: PackageManager,
     private val crypto: Crypto,

app/src/main/java/com/stevesoltys/seedvault/worker/ApkBackupManager.kt

@@ -12,6 +12,7 @@ import com.stevesoltys.seedvault.metadata.MetadataManager
 import com.stevesoltys.seedvault.metadata.PackageState.NOT_ALLOWED
 import com.stevesoltys.seedvault.metadata.PackageState.WAS_STOPPED
 import com.stevesoltys.seedvault.plugins.StoragePlugin
+import com.stevesoltys.seedvault.plugins.StoragePluginManager
 import com.stevesoltys.seedvault.plugins.saf.FILE_BACKUP_METADATA
 import com.stevesoltys.seedvault.settings.SettingsManager
 import com.stevesoltys.seedvault.transport.backup.PackageService
@@ -28,7 +29,7 @@ internal class ApkBackupManager(
     private val metadataManager: MetadataManager,
     private val packageService: PackageService,
     private val apkBackup: ApkBackup,
-    private val plugin: StoragePlugin,
+    private val pluginManager: StoragePluginManager,
     private val nm: BackupNotificationManager,
 ) {
 
@@ -50,7 +51,7 @@ internal class ApkBackupManager(
             keepTrying {
                 // upload all local changes only at the end,
                 // so we don't have to re-upload the metadata
-                plugin.getMetadataOutputStream().use { outputStream ->
+                pluginManager.appPlugin.getMetadataOutputStream().use { outputStream ->
                     metadataManager.uploadMetadata(outputStream)
                 }
             }
@@ -102,7 +103,7 @@ internal class ApkBackupManager(
         return try {
             apkBackup.backupApkIfNecessary(packageInfo) { name ->
                 val token = settingsManager.getToken() ?: throw IOException("no current token")
-                plugin.getOutputStream(token, name)
+                pluginManager.appPlugin.getOutputStream(token, name)
             }?.let { packageMetadata ->
                 metadataManager.onApkBackedUp(packageInfo, packageMetadata)
                 true
@@ -125,7 +126,9 @@ internal class ApkBackupManager(
         }
     }
 
-    private suspend fun StoragePlugin.getMetadataOutputStream(token: Long? = null): OutputStream {
+    private suspend fun StoragePlugin<*>.getMetadataOutputStream(
+        token: Long? = null,
+    ): OutputStream {
         val t = token ?: settingsManager.getToken() ?: throw IOException("no current token")
         return getOutputStream(t, FILE_BACKUP_METADATA)
     }

app/src/main/java/com/stevesoltys/seedvault/worker/WorkerModule.kt

@@ -31,7 +31,7 @@ val workerModule = module {
             metadataManager = get(),
             packageService = get(),
             apkBackup = get(),
-            plugin = get(),
+            pluginManager = get(),
             nm = get()
         )
     }

app/src/test/java/com/stevesoltys/seedvault/TestApp.kt

@@ -8,7 +8,7 @@ import com.stevesoltys.seedvault.crypto.KeyManager
 import com.stevesoltys.seedvault.crypto.KeyManagerTestImpl
 import com.stevesoltys.seedvault.header.headerModule
 import com.stevesoltys.seedvault.metadata.metadataModule
-import com.stevesoltys.seedvault.plugins.saf.documentsProviderModule
+import com.stevesoltys.seedvault.plugins.saf.storagePluginModuleSaf
 import com.stevesoltys.seedvault.restore.install.installModule
 import com.stevesoltys.seedvault.settings.SettingsManager
 import com.stevesoltys.seedvault.transport.backup.backupModule
@@ -42,7 +42,7 @@ class TestApp : App() {
                     testCryptoModule,
                     headerModule,
                     metadataModule,
-                    documentsProviderModule, // storage plugin
+                    storagePluginModuleSaf, // storage plugin
                     backupModule,
                     restoreModule,
                     installModule,

app/src/test/java/com/stevesoltys/seedvault/plugins/saf/StoragePluginTest.kt

@@ -11,7 +11,6 @@ import io.mockk.mockkStatic
 import kotlinx.coroutines.runBlocking
 import org.junit.jupiter.api.Test
 
-@Suppress("BlockingMethodInNonBlockingContext")
 internal class StoragePluginTest : BackupTest() {
 
     private val storage = mockk<DocumentsStorage>()
@@ -39,7 +38,7 @@ internal class StoragePluginTest : BackupTest() {
         // get current set dir and for that the current token
         every { storage getProperty "currentToken" } returns token
         every { settingsManager.getToken() } returns token
-        every { storage getProperty "storage" } returns null // just to check if isUsb
+        every { storage getProperty "safStorage" } returns null // just to check if isUsb
         coEvery { storage.getSetDir(token) } returns setDir
         // delete contents of current set dir
         coEvery { setDir.listFilesBlocking(context) } returns listOf(backupFile)

app/src/test/java/com/stevesoltys/seedvault/restore/install/ApkBackupRestoreTest.kt

@@ -12,6 +12,7 @@ import com.stevesoltys.seedvault.metadata.PackageMetadata
 import com.stevesoltys.seedvault.metadata.PackageMetadataMap
 import com.stevesoltys.seedvault.plugins.LegacyStoragePlugin
 import com.stevesoltys.seedvault.plugins.StoragePlugin
+import com.stevesoltys.seedvault.plugins.StoragePluginManager
 import com.stevesoltys.seedvault.restore.RestorableBackup
 import com.stevesoltys.seedvault.transport.TransportTest
 import com.stevesoltys.seedvault.worker.ApkBackup
@@ -38,7 +39,6 @@ import java.nio.file.Path
 import kotlin.random.Random
 
 @ExperimentalCoroutinesApi
-@Suppress("BlockingMethodInNonBlockingContext")
 internal class ApkBackupRestoreTest : TransportTest() {
 
     private val pm: PackageManager = mockk()
@@ -46,16 +46,17 @@ internal class ApkBackupRestoreTest : TransportTest() {
         every { packageManager } returns pm
     }
 
+    private val storagePluginManager: StoragePluginManager = mockk()
     @Suppress("Deprecation")
     private val legacyStoragePlugin: LegacyStoragePlugin = mockk()
-    private val storagePlugin: StoragePlugin = mockk()
+    private val storagePlugin: StoragePlugin<*> = mockk()
     private val splitCompatChecker: ApkSplitCompatibilityChecker = mockk()
     private val apkInstaller: ApkInstaller = mockk()
 
     private val apkBackup = ApkBackup(pm, crypto, settingsManager, metadataManager)
     private val apkRestore: ApkRestore = ApkRestore(
         context = strictContext,
-        storagePlugin = storagePlugin,
+        pluginManager = storagePluginManager,
         legacyStoragePlugin = legacyStoragePlugin,
         crypto = crypto,
         splitCompatChecker = splitCompatChecker,
@@ -90,6 +91,7 @@ internal class ApkBackupRestoreTest : TransportTest() {
 
     init {
         mockkStatic(PackageUtils::class)
+        every { storagePluginManager.appPlugin } returns storagePlugin
     }
 
     @Test

app/src/test/java/com/stevesoltys/seedvault/restore/install/ApkRestoreTest.kt

@@ -15,6 +15,7 @@ import com.stevesoltys.seedvault.metadata.PackageMetadata
 import com.stevesoltys.seedvault.metadata.PackageMetadataMap
 import com.stevesoltys.seedvault.plugins.LegacyStoragePlugin
 import com.stevesoltys.seedvault.plugins.StoragePlugin
+import com.stevesoltys.seedvault.plugins.StoragePluginManager
 import com.stevesoltys.seedvault.restore.RestorableBackup
 import com.stevesoltys.seedvault.restore.install.ApkInstallState.FAILED
 import com.stevesoltys.seedvault.restore.install.ApkInstallState.FAILED_SYSTEM_APP
@@ -41,7 +42,6 @@ import java.io.IOException
 import java.nio.file.Path
 import kotlin.random.Random
 
-@Suppress("BlockingMethodInNonBlockingContext")
 @ExperimentalCoroutinesApi
 internal class ApkRestoreTest : TransportTest() {
 
@@ -49,18 +49,19 @@ internal class ApkRestoreTest : TransportTest() {
     private val strictContext: Context = mockk<Context>().apply {
         every { packageManager } returns pm
     }
-    private val storagePlugin: StoragePlugin = mockk()
+    private val storagePluginManager: StoragePluginManager = mockk()
+    private val storagePlugin: StoragePlugin<*> = mockk()
     private val legacyStoragePlugin: LegacyStoragePlugin = mockk()
     private val splitCompatChecker: ApkSplitCompatibilityChecker = mockk()
     private val apkInstaller: ApkInstaller = mockk()
 
     private val apkRestore: ApkRestore = ApkRestore(
-        strictContext,
+        context = strictContext,
-        storagePlugin,
+        pluginManager = storagePluginManager,
-        legacyStoragePlugin,
+        legacyStoragePlugin = legacyStoragePlugin,
-        crypto,
+        crypto = crypto,
-        splitCompatChecker,
+        splitCompatChecker = splitCompatChecker,
-        apkInstaller
+        apkInstaller = apkInstaller,
     )
 
     private val icon: Drawable = mockk()
@@ -85,6 +86,8 @@ internal class ApkRestoreTest : TransportTest() {
     init {
         // as we don't do strict signature checking, we can use a relaxed mock
         packageInfo.signingInfo = mockk(relaxed = true)
+
+        every { storagePluginManager.appPlugin } returns storagePlugin
     }
 
     @Test

app/src/test/java/com/stevesoltys/seedvault/transport/CoordinatorIntegrationTest.kt

@@ -17,6 +17,7 @@ import com.stevesoltys.seedvault.metadata.MetadataReaderImpl
 import com.stevesoltys.seedvault.metadata.PackageMetadata
 import com.stevesoltys.seedvault.plugins.LegacyStoragePlugin
 import com.stevesoltys.seedvault.plugins.StoragePlugin
+import com.stevesoltys.seedvault.plugins.StoragePluginManager
 import com.stevesoltys.seedvault.plugins.saf.FILE_BACKUP_METADATA
 import com.stevesoltys.seedvault.transport.backup.BackupCoordinator
 import com.stevesoltys.seedvault.transport.backup.FullBackup
@@ -46,7 +47,6 @@ import java.io.ByteArrayInputStream
 import java.io.ByteArrayOutputStream
 import kotlin.random.Random
 
-@Suppress("BlockingMethodInNonBlockingContext")
 internal class CoordinatorIntegrationTest : TransportTest() {
 
     private val inputFactory = mockk<InputFactory>()
@@ -58,18 +58,20 @@ internal class CoordinatorIntegrationTest : TransportTest() {
     private val metadataReader = MetadataReaderImpl(cryptoImpl)
     private val notificationManager = mockk<BackupNotificationManager>()
     private val dbManager = TestKvDbManager()
+    private val storagePluginManager: StoragePluginManager = mockk()
 
     @Suppress("Deprecation")
     private val legacyPlugin = mockk<LegacyStoragePlugin>()
-    private val backupPlugin = mockk<StoragePlugin>()
+    private val backupPlugin = mockk<StoragePlugin<*>>()
     private val kvBackup =
-        KVBackup(backupPlugin, settingsManager, inputFactory, cryptoImpl, dbManager)
+        KVBackup(storagePluginManager, settingsManager, inputFactory, cryptoImpl, dbManager)
-    private val fullBackup = FullBackup(backupPlugin, settingsManager, inputFactory, cryptoImpl)
+    private val fullBackup =
+        FullBackup(storagePluginManager, settingsManager, inputFactory, cryptoImpl)
     private val apkBackup = mockk<ApkBackup>()
     private val packageService: PackageService = mockk()
     private val backup = BackupCoordinator(
         context,
-        backupPlugin,
+        storagePluginManager,
         kvBackup,
         fullBackup,
         clock,
@@ -80,7 +82,7 @@ internal class CoordinatorIntegrationTest : TransportTest() {
     )
 
     private val kvRestore = KVRestore(
-        backupPlugin,
+        storagePluginManager,
         legacyPlugin,
         outputFactory,
         headerReader,
@@ -88,14 +90,14 @@ internal class CoordinatorIntegrationTest : TransportTest() {
         dbManager
     )
     private val fullRestore =
-        FullRestore(backupPlugin, legacyPlugin, outputFactory, headerReader, cryptoImpl)
+        FullRestore(storagePluginManager, legacyPlugin, outputFactory, headerReader, cryptoImpl)
     private val restore = RestoreCoordinator(
         context,
         crypto,
         settingsManager,
         metadataManager,
         notificationManager,
-        backupPlugin,
+        storagePluginManager,
         kvRestore,
         fullRestore,
         metadataReader
@@ -113,6 +115,10 @@ internal class CoordinatorIntegrationTest : TransportTest() {
     // as we use real crypto, we need a real name for packageInfo
     private val realName = cryptoImpl.getNameForPackage(salt, packageInfo.packageName)
 
+    init {
+        every { storagePluginManager.appPlugin } returns backupPlugin
+    }
+
     @Test
     fun `test key-value backup and restore with 2 records`() = runBlocking {
         val value = CapturingSlot<ByteArray>()

app/src/test/java/com/stevesoltys/seedvault/transport/backup/BackupCoordinatorTest.kt

@@ -16,6 +16,7 @@ import com.stevesoltys.seedvault.metadata.PackageMetadata
 import com.stevesoltys.seedvault.metadata.PackageState.NO_DATA
 import com.stevesoltys.seedvault.metadata.PackageState.QUOTA_EXCEEDED
 import com.stevesoltys.seedvault.plugins.StoragePlugin
+import com.stevesoltys.seedvault.plugins.StoragePluginManager
 import com.stevesoltys.seedvault.plugins.saf.FILE_BACKUP_METADATA
 import com.stevesoltys.seedvault.plugins.saf.SafStorage
 import com.stevesoltys.seedvault.ui.notification.BackupNotificationManager
@@ -33,10 +34,9 @@ import java.io.IOException
 import java.io.OutputStream
 import kotlin.random.Random
 
-@Suppress("BlockingMethodInNonBlockingContext")
 internal class BackupCoordinatorTest : BackupTest() {
 
-    private val plugin = mockk<StoragePlugin>()
+    private val pluginManager = mockk<StoragePluginManager>()
     private val kv = mockk<KVBackup>()
     private val full = mockk<FullBackup>()
     private val apkBackup = mockk<ApkBackup>()
@@ -44,27 +44,32 @@ internal class BackupCoordinatorTest : BackupTest() {
     private val packageService = mockk<PackageService>()
 
     private val backup = BackupCoordinator(
-        context,
+        context = context,
-        plugin,
+        pluginManager = pluginManager,
-        kv,
+        kv = kv,
-        full,
+        full = full,
-        clock,
+        clock = clock,
-        packageService,
+        packageService = packageService,
-        metadataManager,
+        metadataManager = metadataManager,
-        settingsManager,
+        settingsManager = settingsManager,
-        notificationManager
+        nm = notificationManager,
     )
 
+    private val plugin = mockk<StoragePlugin<*>>()
     private val metadataOutputStream = mockk<OutputStream>()
     private val fileDescriptor: ParcelFileDescriptor = mockk()
     private val packageMetadata: PackageMetadata = mockk()
     private val safStorage = SafStorage(
-        uri = Uri.EMPTY,
+        config = Uri.EMPTY,
         name = getRandomString(),
         isUsb = false,
-        requiresNetwork = false
+        requiresNetwork = false,
     )
 
+    init {
+        every { pluginManager.appPlugin } returns plugin
+    }
+
     @Test
     fun `device initialization succeeds and delegates to plugin`() = runBlocking {
         expectStartNewRestoreSet()
@@ -90,7 +95,7 @@ internal class BackupCoordinatorTest : BackupTest() {
         expectStartNewRestoreSet()
         coEvery { plugin.initializeDevice() } throws IOException()
         every { metadataManager.requiresInit } returns maybeTrue
-        every { settingsManager.canDoBackupNow() } returns !maybeTrue
+        every { pluginManager.canDoBackupNow() } returns !maybeTrue
         every { notificationManager.onBackupError() } just Runs
 
         assertEquals(TRANSPORT_ERROR, backup.initializeDevice())
@@ -109,7 +114,7 @@ internal class BackupCoordinatorTest : BackupTest() {
             expectStartNewRestoreSet()
             coEvery { plugin.initializeDevice() } throws IOException()
             every { metadataManager.requiresInit } returns false
-            every { settingsManager.canDoBackupNow() } returns false
+            every { pluginManager.canDoBackupNow() } returns false
 
             assertEquals(TRANSPORT_ERROR, backup.initializeDevice())
 
@@ -125,7 +130,7 @@ internal class BackupCoordinatorTest : BackupTest() {
     fun `performIncrementalBackup of @pm@ causes re-init when legacy format`() = runBlocking {
         val packageInfo = PackageInfo().apply { packageName = MAGIC_PACKAGE_MANAGER }
 
-        every { settingsManager.canDoBackupNow() } returns true
+        every { pluginManager.canDoBackupNow() } returns true
         every { metadataManager.requiresInit } returns true
 
         // start new restore set
@@ -224,7 +229,7 @@ internal class BackupCoordinatorTest : BackupTest() {
         every { kv.getCurrentSize() } returns 42L
 
         coEvery { kv.finishBackup() } returns TRANSPORT_OK
-        every { settingsManager.canDoBackupNow() } returns false
+        every { pluginManager.canDoBackupNow() } returns false
 
         assertEquals(TRANSPORT_OK, backup.finishBackup())
     }
@@ -290,7 +295,7 @@ internal class BackupCoordinatorTest : BackupTest() {
             )
         } just Runs
         coEvery { full.cancelFullBackup(token, metadata.salt, false) } just Runs
-        every { settingsManager.getSafStorage() } returns safStorage
+        every { pluginManager.storageProperties } returns safStorage
         every { settingsManager.useMeteredNetwork } returns false
         every { metadataOutputStream.close() } just Runs
 
@@ -340,7 +345,7 @@ internal class BackupCoordinatorTest : BackupTest() {
             )
         } just Runs
         coEvery { full.cancelFullBackup(token, metadata.salt, false) } just Runs
-        every { settingsManager.getSafStorage() } returns safStorage
+        every { pluginManager.storageProperties } returns safStorage
         every { settingsManager.useMeteredNetwork } returns false
         every { metadataOutputStream.close() } just Runs
 

app/src/test/java/com/stevesoltys/seedvault/transport/backup/FullBackupTest.kt

@@ -7,6 +7,7 @@ import android.app.backup.BackupTransport.TRANSPORT_QUOTA_EXCEEDED
 import com.stevesoltys.seedvault.header.VERSION
 import com.stevesoltys.seedvault.header.getADForFull
 import com.stevesoltys.seedvault.plugins.StoragePlugin
+import com.stevesoltys.seedvault.plugins.StoragePluginManager
 import io.mockk.Runs
 import io.mockk.coEvery
 import io.mockk.every
@@ -21,16 +22,20 @@ import java.io.FileInputStream
 import java.io.IOException
 import kotlin.random.Random
 
-@Suppress("BlockingMethodInNonBlockingContext")
 internal class FullBackupTest : BackupTest() {
 
-    private val plugin = mockk<StoragePlugin>()
+    private val storagePluginManager: StoragePluginManager = mockk()
-    private val backup = FullBackup(plugin, settingsManager, inputFactory, crypto)
+    private val plugin = mockk<StoragePlugin<*>>()
+    private val backup = FullBackup(storagePluginManager, settingsManager, inputFactory, crypto)
 
     private val bytes = ByteArray(23).apply { Random.nextBytes(this) }
     private val inputStream = mockk<FileInputStream>()
     private val ad = getADForFull(VERSION, packageInfo.packageName)
 
+    init {
+        every { storagePluginManager.appPlugin } returns plugin
+    }
+
     @Test
     fun `has no initial state`() {
         assertFalse(backup.hasState())

app/src/test/java/com/stevesoltys/seedvault/transport/backup/KVBackupTest.kt

@@ -13,6 +13,7 @@ import com.stevesoltys.seedvault.header.MAX_KEY_LENGTH_SIZE
 import com.stevesoltys.seedvault.header.VERSION
 import com.stevesoltys.seedvault.header.getADForKV
 import com.stevesoltys.seedvault.plugins.StoragePlugin
+import com.stevesoltys.seedvault.plugins.StoragePluginManager
 import io.mockk.CapturingSlot
 import io.mockk.Runs
 import io.mockk.coEvery
@@ -30,22 +31,26 @@ import java.io.ByteArrayInputStream
 import java.io.IOException
 import kotlin.random.Random
 
-@Suppress("BlockingMethodInNonBlockingContext")
 internal class KVBackupTest : BackupTest() {
 
-    private val plugin = mockk<StoragePlugin>()
+    private val pluginManager = mockk<StoragePluginManager>()
     private val dataInput = mockk<BackupDataInput>()
     private val dbManager = mockk<KvDbManager>()
 
-    private val backup = KVBackup(plugin, settingsManager, inputFactory, crypto, dbManager)
+    private val backup = KVBackup(pluginManager, settingsManager, inputFactory, crypto, dbManager)
 
     private val db = mockk<KVDb>()
+    private val plugin = mockk<StoragePlugin<*>>()
     private val packageName = packageInfo.packageName
     private val key = getRandomString(MAX_KEY_LENGTH_SIZE)
     private val dataValue = Random.nextBytes(23)
     private val dbBytes = Random.nextBytes(42)
     private val inputStream = ByteArrayInputStream(dbBytes)
 
+    init {
+        every { pluginManager.appPlugin } returns plugin
+    }
+
     @Test
     fun `has no initial state`() {
         assertFalse(backup.hasState())
@@ -231,7 +236,7 @@ internal class KVBackupTest : BackupTest() {
         every { dbManager.existsDb(pmPackageInfo.packageName) } returns false
         every { crypto.getNameForPackage(salt, pmPackageInfo.packageName) } returns name
         every { dbManager.getDb(pmPackageInfo.packageName) } returns db
-        every { settingsManager.canDoBackupNow() } returns false
+        every { pluginManager.canDoBackupNow() } returns false
         every { db.put(key, dataValue) } just Runs
         getDataInput(listOf(true, false))
 

app/src/test/java/com/stevesoltys/seedvault/transport/restore/FullRestoreTest.kt

@@ -13,6 +13,7 @@ import com.stevesoltys.seedvault.header.VersionHeader
 import com.stevesoltys.seedvault.header.getADForFull
 import com.stevesoltys.seedvault.plugins.LegacyStoragePlugin
 import com.stevesoltys.seedvault.plugins.StoragePlugin
+import com.stevesoltys.seedvault.plugins.StoragePluginManager
 import io.mockk.CapturingSlot
 import io.mockk.Runs
 import io.mockk.coEvery
@@ -31,17 +32,27 @@ import java.io.IOException
 import java.security.GeneralSecurityException
 import kotlin.random.Random
 
-@Suppress("BlockingMethodInNonBlockingContext")
 internal class FullRestoreTest : RestoreTest() {
 
-    private val plugin = mockk<StoragePlugin>()
+    private val storagePluginManager: StoragePluginManager = mockk()
+    private val plugin = mockk<StoragePlugin<*>>()
     private val legacyPlugin = mockk<LegacyStoragePlugin>()
-    private val restore = FullRestore(plugin, legacyPlugin, outputFactory, headerReader, crypto)
+    private val restore = FullRestore(
+        pluginManager = storagePluginManager,
+        legacyPlugin = legacyPlugin,
+        outputFactory = outputFactory,
+        headerReader = headerReader,
+        crypto = crypto,
+    )
 
     private val encrypted = getRandomByteArray()
     private val outputStream = ByteArrayOutputStream()
     private val ad = getADForFull(VERSION, packageInfo.packageName)
 
+    init {
+        every { storagePluginManager.appPlugin } returns plugin
+    }
+
     @Test
     fun `has no initial state`() {
         assertFalse(restore.hasState())

app/src/test/java/com/stevesoltys/seedvault/transport/restore/KVRestoreTest.kt

@@ -12,6 +12,7 @@ import com.stevesoltys.seedvault.header.VersionHeader
 import com.stevesoltys.seedvault.header.getADForKV
 import com.stevesoltys.seedvault.plugins.LegacyStoragePlugin
 import com.stevesoltys.seedvault.plugins.StoragePlugin
+import com.stevesoltys.seedvault.plugins.StoragePluginManager
 import com.stevesoltys.seedvault.transport.backup.KVDb
 import com.stevesoltys.seedvault.transport.backup.KvDbManager
 import io.mockk.Runs
@@ -33,15 +34,22 @@ import java.security.GeneralSecurityException
 import java.util.zip.GZIPOutputStream
 import kotlin.random.Random
 
-@Suppress("BlockingMethodInNonBlockingContext")
 internal class KVRestoreTest : RestoreTest() {
 
-    private val plugin = mockk<StoragePlugin>()
+    private val storagePluginManager: StoragePluginManager = mockk()
+    private val plugin = mockk<StoragePlugin<*>>()
+    @Suppress("DEPRECATION")
     private val legacyPlugin = mockk<LegacyStoragePlugin>()
     private val dbManager = mockk<KvDbManager>()
     private val output = mockk<BackupDataOutput>()
-    private val restore =
+    private val restore = KVRestore(
-        KVRestore(plugin, legacyPlugin, outputFactory, headerReader, crypto, dbManager)
+        pluginManager = storagePluginManager,
+        legacyPlugin = legacyPlugin,
+        outputFactory = outputFactory,
+        headerReader = headerReader,
+        crypto = crypto,
+        dbManager = dbManager,
+    )
 
     private val db = mockk<KVDb>()
     private val ad = getADForKV(VERSION, packageInfo.packageName)
@@ -60,6 +68,8 @@ internal class KVRestoreTest : RestoreTest() {
     init {
         // for InputStream#readBytes()
         mockkStatic("kotlin.io.ByteStreamsKt")
+
+        every { storagePluginManager.appPlugin } returns plugin
     }
 
     @Test
@@ -180,7 +190,6 @@ internal class KVRestoreTest : RestoreTest() {
     }
 
     @Test
-    @Suppress("Deprecation")
     fun `v0 listing records throws`() = runBlocking {
         restore.initializeState(0x00, token, name, packageInfo)
 

app/src/test/java/com/stevesoltys/seedvault/transport/restore/RestoreCoordinatorTest.kt

@@ -16,6 +16,7 @@ import com.stevesoltys.seedvault.metadata.MetadataReader
 import com.stevesoltys.seedvault.metadata.PackageMetadata
 import com.stevesoltys.seedvault.plugins.EncryptedMetadata
 import com.stevesoltys.seedvault.plugins.StoragePlugin
+import com.stevesoltys.seedvault.plugins.StoragePluginManager
 import com.stevesoltys.seedvault.plugins.saf.SafStorage
 import com.stevesoltys.seedvault.transport.TransportTest
 import com.stevesoltys.seedvault.ui.notification.BackupNotificationManager
@@ -35,25 +36,25 @@ import java.io.IOException
 import java.io.InputStream
 import kotlin.random.Random
 
-@Suppress("BlockingMethodInNonBlockingContext")
 internal class RestoreCoordinatorTest : TransportTest() {
 
     private val notificationManager: BackupNotificationManager = mockk()
-    private val plugin = mockk<StoragePlugin>()
+    private val storagePluginManager: StoragePluginManager = mockk()
+    private val plugin = mockk<StoragePlugin<*>>()
     private val kv = mockk<KVRestore>()
     private val full = mockk<FullRestore>()
     private val metadataReader = mockk<MetadataReader>()
 
     private val restore = RestoreCoordinator(
-        context,
+        context = context,
-        crypto,
+        crypto = crypto,
-        settingsManager,
+        settingsManager = settingsManager,
-        metadataManager,
+        metadataManager = metadataManager,
-        notificationManager,
+        notificationManager = notificationManager,
-        plugin,
+        pluginManager = storagePluginManager,
-        kv,
+        kv = kv,
-        full,
+        full = full,
-        metadataReader
+        metadataReader = metadataReader,
     )
 
     private val inputStream = mockk<InputStream>()
@@ -71,6 +72,8 @@ internal class RestoreCoordinatorTest : TransportTest() {
     init {
         metadata.packageMetadataMap[packageInfo2.packageName] =
             PackageMetadata(backupType = BackupType.FULL)
+
+        every { storagePluginManager.appPlugin } returns plugin
     }
 
     @Test
@@ -164,7 +167,7 @@ internal class RestoreCoordinatorTest : TransportTest() {
     @Test
     fun `startRestore() optimized auto-restore with removed storage shows notification`() =
         runBlocking {
-            every { settingsManager.getSafStorage() } returns safStorage
+            every { storagePluginManager.storageProperties } returns safStorage
             every { safStorage.isUnavailableUsb(context) } returns true
             every { metadataManager.getPackageMetadata(packageName) } returns PackageMetadata(42L)
             every { safStorage.name } returns storageName
@@ -188,7 +191,7 @@ internal class RestoreCoordinatorTest : TransportTest() {
     @Test
     fun `startRestore() optimized auto-restore with available storage shows no notification`() =
         runBlocking {
-            every { settingsManager.getSafStorage() } returns safStorage
+            every { storagePluginManager.storageProperties } returns safStorage
             every { safStorage.isUnavailableUsb(context) } returns false
 
             restore.beforeStartRestore(metadata)
@@ -204,7 +207,7 @@ internal class RestoreCoordinatorTest : TransportTest() {
 
     @Test
     fun `startRestore() with removed storage shows no notification`() = runBlocking {
-        every { settingsManager.getSafStorage() } returns safStorage
+        every { storagePluginManager.storageProperties } returns safStorage
         every { safStorage.isUnavailableUsb(context) } returns true
         every { metadataManager.getPackageMetadata(packageName) } returns null
 

app/src/test/java/com/stevesoltys/seedvault/transport/restore/RestoreV0IntegrationTest.kt

@@ -15,6 +15,7 @@ import com.stevesoltys.seedvault.header.HeaderReaderImpl
 import com.stevesoltys.seedvault.metadata.MetadataReaderImpl
 import com.stevesoltys.seedvault.plugins.LegacyStoragePlugin
 import com.stevesoltys.seedvault.plugins.StoragePlugin
+import com.stevesoltys.seedvault.plugins.StoragePluginManager
 import com.stevesoltys.seedvault.toByteArrayFromHex
 import com.stevesoltys.seedvault.transport.TransportTest
 import com.stevesoltys.seedvault.transport.backup.KvDbManager
@@ -35,7 +36,6 @@ import javax.crypto.spec.SecretKeySpec
 /**
  * Tests that we can still restore Version 0 backups with current code.
  */
-@Suppress("BlockingMethodInNonBlockingContext")
 internal class RestoreV0IntegrationTest : TransportTest() {
 
     private val outputFactory = mockk<OutputFactory>()
@@ -49,30 +49,31 @@ internal class RestoreV0IntegrationTest : TransportTest() {
     private val dbManager = mockk<KvDbManager>()
     private val metadataReader = MetadataReaderImpl(cryptoImpl)
     private val notificationManager = mockk<BackupNotificationManager>()
+    private val storagePluginManager: StoragePluginManager = mockk()
 
     @Suppress("Deprecation")
     private val legacyPlugin = mockk<LegacyStoragePlugin>()
-    private val backupPlugin = mockk<StoragePlugin>()
+    private val backupPlugin = mockk<StoragePlugin<*>>()
     private val kvRestore = KVRestore(
-        backupPlugin,
+        pluginManager = storagePluginManager,
-        legacyPlugin,
+        legacyPlugin = legacyPlugin,
-        outputFactory,
+        outputFactory = outputFactory,
-        headerReader,
+        headerReader = headerReader,
-        cryptoImpl,
+        crypto = cryptoImpl,
-        dbManager
+        dbManager = dbManager,
     )
     private val fullRestore =
-        FullRestore(backupPlugin, legacyPlugin, outputFactory, headerReader, cryptoImpl)
+        FullRestore(storagePluginManager, legacyPlugin, outputFactory, headerReader, cryptoImpl)
     private val restore = RestoreCoordinator(
-        context,
+        context = context,
-        crypto,
+        crypto = crypto,
-        settingsManager,
+        settingsManager = settingsManager,
-        metadataManager,
+        metadataManager = metadataManager,
-        notificationManager,
+        notificationManager = notificationManager,
-        backupPlugin,
+        pluginManager = storagePluginManager,
-        kvRestore,
+        kv = kvRestore,
-        fullRestore,
+        full = fullRestore,
-        metadataReader
+        metadataReader = metadataReader,
     ).apply { beforeStartRestore(metadata.copy(version = 0x00)) }
 
     private val fileDescriptor = mockk<ParcelFileDescriptor>(relaxed = true)
@@ -116,6 +117,10 @@ internal class RestoreV0IntegrationTest : TransportTest() {
     private val key2 = "RestoreKey2"
     private val key264 = key2.encodeBase64()
 
+    init {
+        every { storagePluginManager.appPlugin } returns backupPlugin
+    }
+
     @Test
     fun `test key-value backup and restore with 2 records`() = runBlocking {
         val encryptedAppData = ("00002A2C701AA7C91D1286E265D29169B25C41E6D0" +

app/src/test/java/com/stevesoltys/seedvault/worker/ApkBackupManagerTest.kt

@@ -10,6 +10,7 @@ import com.stevesoltys.seedvault.metadata.PackageState.NOT_ALLOWED
 import com.stevesoltys.seedvault.metadata.PackageState.UNKNOWN_ERROR
 import com.stevesoltys.seedvault.metadata.PackageState.WAS_STOPPED
 import com.stevesoltys.seedvault.plugins.StoragePlugin
+import com.stevesoltys.seedvault.plugins.StoragePluginManager
 import com.stevesoltys.seedvault.plugins.saf.FILE_BACKUP_METADATA
 import com.stevesoltys.seedvault.transport.TransportTest
 import com.stevesoltys.seedvault.transport.backup.PackageService
@@ -32,7 +33,8 @@ internal class ApkBackupManagerTest : TransportTest() {
 
     private val packageService: PackageService = mockk()
     private val apkBackup: ApkBackup = mockk()
-    private val plugin: StoragePlugin = mockk()
+    private val storagePluginManager: StoragePluginManager = mockk()
+    private val plugin: StoragePlugin<*> = mockk()
     private val nm: BackupNotificationManager = mockk()
 
     private val apkBackupManager = ApkBackupManager(
@@ -41,13 +43,17 @@ internal class ApkBackupManagerTest : TransportTest() {
         metadataManager = metadataManager,
         packageService = packageService,
         apkBackup = apkBackup,
-        plugin = plugin,
+        pluginManager = storagePluginManager,
         nm = nm,
     )
 
     private val metadataOutputStream = mockk<OutputStream>()
     private val packageMetadata: PackageMetadata = mockk()
 
+    init {
+        every { storagePluginManager.appPlugin } returns plugin
+    }
+
     @Test
     fun `Package state of app that is not stopped gets recorded as not-allowed`() = runBlocking {
         every { nm.onAppsNotBackedUp() } just Runs

app/src/test/java/com/stevesoltys/seedvault/worker/ApkBackupTest.kt

@@ -38,7 +38,6 @@ import java.io.OutputStream
 import java.nio.file.Path
 import kotlin.random.Random
 
-@Suppress("BlockingMethodInNonBlockingContext")
 internal class ApkBackupTest : BackupTest() {
 
     private val pm: PackageManager = mockk()

storage/demo/src/main/java/de/grobox/storagebackuptester/App.kt

@@ -18,7 +18,7 @@ class App : Application() {
     val settingsManager: SettingsManager by lazy { SettingsManager(applicationContext) }
     val storageBackup: StorageBackup by lazy {
         val plugin = TestSafStoragePlugin(this) { settingsManager.getBackupLocation() }
-        StorageBackup(this, plugin)
+        StorageBackup(this, { plugin })
     }
 
     override fun onCreate() {

storage/lib/src/main/java/org/calyxos/backup/storage/api/StorageBackup.kt

@@ -36,10 +36,9 @@ import java.util.concurrent.atomic.AtomicBoolean
 
 private const val TAG = "StorageBackup"
 
-@Suppress("BlockingMethodInNonBlockingContext")
 public class StorageBackup(
     private val context: Context,
-    private val plugin: StoragePlugin,
+    private val pluginGetter: () -> StoragePlugin,
     private val dispatcher: CoroutineDispatcher = Dispatchers.IO,
 ) {
 
@@ -50,18 +49,18 @@ public class StorageBackup(
     private val uriStore by lazy { db.getUriStore() }
 
     private val mediaScanner by lazy { MediaScanner(context) }
-    private val snapshotRetriever = SnapshotRetriever(plugin)
+    private val snapshotRetriever = SnapshotRetriever(pluginGetter)
-    private val chunksCacheRepopulater = ChunksCacheRepopulater(db, plugin, snapshotRetriever)
+    private val chunksCacheRepopulater = ChunksCacheRepopulater(db, pluginGetter, snapshotRetriever)
     private val backup by lazy {
         val documentScanner = DocumentScanner(context)
         val fileScanner = FileScanner(uriStore, mediaScanner, documentScanner)
-        Backup(context, db, fileScanner, plugin, chunksCacheRepopulater)
+        Backup(context, db, fileScanner, pluginGetter, chunksCacheRepopulater)
     }
     private val restore by lazy {
-        Restore(context, plugin, snapshotRetriever, FileRestore(context, mediaScanner))
+        Restore(context, pluginGetter, snapshotRetriever, FileRestore(context, mediaScanner))
     }
     private val retention = RetentionManager(context)
-    private val pruner by lazy { Pruner(db, retention, plugin, snapshotRetriever) }
+    private val pruner by lazy { Pruner(db, retention, pluginGetter, snapshotRetriever) }
 
     private val backupRunning = AtomicBoolean(false)
     private val restoreRunning = AtomicBoolean(false)
@@ -109,7 +108,7 @@ public class StorageBackup(
      * (see [deleteAllSnapshots]) as well as clears local cache (see [clearCache]).
      */
     public suspend fun init() {
-        plugin.init()
+        pluginGetter().init()
         deleteAllSnapshots()
         clearCache()
     }
@@ -123,9 +122,9 @@ public class StorageBackup(
      */
     public suspend fun deleteAllSnapshots(): Unit = withContext(dispatcher) {
         try {
-            plugin.getCurrentBackupSnapshots().forEach {
+            pluginGetter().getCurrentBackupSnapshots().forEach {
                 try {
-                    plugin.deleteBackupSnapshot(it)
+                    pluginGetter().deleteBackupSnapshot(it)
                 } catch (e: IOException) {
                     Log.e(TAG, "Error deleting snapshot $it", e)
                 }

storage/lib/src/main/java/org/calyxos/backup/storage/backup/Backup.kt

@@ -35,12 +35,11 @@ internal class BackupResult(
     )
 }
 
-@Suppress("BlockingMethodInNonBlockingContext")
 internal class Backup(
     private val context: Context,
     private val db: Db,
     private val fileScanner: FileScanner,
-    private val storagePlugin: StoragePlugin,
+    private val storagePluginGetter: () -> StoragePlugin,
     private val cacheRepopulater: ChunksCacheRepopulater,
     chunkSizeMax: Int = CHUNK_SIZE_MAX,
     private val streamCrypto: StreamCrypto = StreamCrypto,
@@ -54,6 +53,7 @@ internal class Backup(
     }
 
     private val contentResolver = context.contentResolver
+    private val storagePlugin get() = storagePluginGetter()
     private val filesCache = db.getFilesCache()
     private val chunksCache = db.getChunksCache()
 

storage/lib/src/main/java/org/calyxos/backup/storage/backup/ChunksCacheRepopulater.kt

@@ -19,10 +19,9 @@ import kotlin.time.toDuration
 
 private const val TAG = "ChunksCacheRepopulater"
 
-@Suppress("BlockingMethodInNonBlockingContext")
 internal class ChunksCacheRepopulater(
     private val db: Db,
-    private val storagePlugin: StoragePlugin,
+    private val storagePlugin: () -> StoragePlugin,
     private val snapshotRetriever: SnapshotRetriever,
 ) {
 
@@ -43,7 +42,7 @@ internal class ChunksCacheRepopulater(
         availableChunkIds: HashSet<String>,
     ) {
         val start = System.currentTimeMillis()
-        val snapshots = storagePlugin.getCurrentBackupSnapshots().mapNotNull { storedSnapshot ->
+        val snapshots = storagePlugin().getCurrentBackupSnapshots().mapNotNull { storedSnapshot ->
             try {
                 snapshotRetriever.getSnapshot(streamKey, storedSnapshot)
             } catch (e: GeneralSecurityException) {
@@ -63,7 +62,7 @@ internal class ChunksCacheRepopulater(
         // delete chunks that are not references by any snapshot anymore
         val chunksToDelete = availableChunkIds.subtract(cachedChunks.map { it.id })
         val deletionDuration = measure {
-            storagePlugin.deleteChunks(chunksToDelete.toList())
+            storagePlugin().deleteChunks(chunksToDelete.toList())
         }
         Log.i(TAG, "Deleting ${chunksToDelete.size} chunks took $deletionDuration")
     }

storage/lib/src/main/java/org/calyxos/backup/storage/plugin/SnapshotRetriever.kt

@@ -14,9 +14,8 @@ import org.calyxos.backup.storage.restore.readVersion
 import java.io.IOException
 import java.security.GeneralSecurityException
 
-@Suppress("BlockingMethodInNonBlockingContext")
 internal class SnapshotRetriever(
-    private val storagePlugin: StoragePlugin,
+    private val storagePlugin: () -> StoragePlugin,
     private val streamCrypto: StreamCrypto = StreamCrypto,
 ) {
 
@@ -26,7 +25,7 @@ internal class SnapshotRetriever(
         InvalidProtocolBufferException::class,
     )
     suspend fun getSnapshot(streamKey: ByteArray, storedSnapshot: StoredSnapshot): BackupSnapshot {
-        return storagePlugin.getBackupSnapshotInputStream(storedSnapshot).use { inputStream ->
+        return storagePlugin().getBackupSnapshotInputStream(storedSnapshot).use { inputStream ->
             val version = inputStream.readVersion()
             val timestamp = storedSnapshot.timestamp
             val ad = streamCrypto.getAssociatedDataForSnapshot(timestamp, version.toByte())

storage/lib/src/main/java/org/calyxos/backup/storage/prune/Pruner.kt

@@ -19,15 +19,15 @@ import kotlin.time.ExperimentalTime
 
 private val TAG = Pruner::class.java.simpleName
 
-@Suppress("BlockingMethodInNonBlockingContext")
 internal class Pruner(
     private val db: Db,
     private val retentionManager: RetentionManager,
-    private val storagePlugin: StoragePlugin,
+    private val storagePluginGetter: () -> StoragePlugin,
     private val snapshotRetriever: SnapshotRetriever,
     streamCrypto: StreamCrypto = StreamCrypto,
 ) {
 
+    private val storagePlugin get() = storagePluginGetter()
     private val chunksCache = db.getChunksCache()
     private val streamKey = try {
         streamCrypto.deriveStreamKey(storagePlugin.getMasterKey())

storage/lib/src/main/java/org/calyxos/backup/storage/restore/AbstractChunkRestore.kt

@@ -14,14 +14,15 @@ import java.io.InputStream
 import java.io.OutputStream
 import java.security.GeneralSecurityException
 
-@Suppress("BlockingMethodInNonBlockingContext")
 internal abstract class AbstractChunkRestore(
-    private val storagePlugin: StoragePlugin,
+    private val storagePluginGetter: () -> StoragePlugin,
     private val fileRestore: FileRestore,
     private val streamCrypto: StreamCrypto,
     private val streamKey: ByteArray,
 ) {
 
+    private val storagePlugin get() = storagePluginGetter()
+
     @Throws(IOException::class, GeneralSecurityException::class)
     protected suspend fun getAndDecryptChunk(
         version: Int,

storage/lib/src/main/java/org/calyxos/backup/storage/restore/MultiChunkRestore.kt

@@ -24,7 +24,7 @@ private const val TAG = "MultiChunkRestore"
 @Suppress("BlockingMethodInNonBlockingContext")
 internal class MultiChunkRestore(
     private val context: Context,
-    storagePlugin: StoragePlugin,
+    storagePlugin: () -> StoragePlugin,
     fileRestore: FileRestore,
     streamCrypto: StreamCrypto,
     streamKey: ByteArray,

storage/lib/src/main/java/org/calyxos/backup/storage/restore/Restore.kt

@@ -28,12 +28,13 @@ private const val TAG = "Restore"
 
 internal class Restore(
     context: Context,
-    private val storagePlugin: StoragePlugin,
+    private val storagePluginGetter: () -> StoragePlugin,
     private val snapshotRetriever: SnapshotRetriever,
     fileRestore: FileRestore,
     streamCrypto: StreamCrypto = StreamCrypto,
 ) {
 
+    private val storagePlugin get() = storagePluginGetter()
     private val streamKey by lazy {
         // This class might get instantiated before the StoragePlugin had time to provide the key
         // so we need to get it lazily here to prevent crashes. We can still crash later,
@@ -47,13 +48,13 @@ internal class Restore(
 
     // lazily instantiate these, so they don't try to get the streamKey too early
     private val zipChunkRestore by lazy {
-        ZipChunkRestore(storagePlugin, fileRestore, streamCrypto, streamKey)
+        ZipChunkRestore(storagePluginGetter, fileRestore, streamCrypto, streamKey)
     }
     private val singleChunkRestore by lazy {
-        SingleChunkRestore(storagePlugin, fileRestore, streamCrypto, streamKey)
+        SingleChunkRestore(storagePluginGetter, fileRestore, streamCrypto, streamKey)
     }
     private val multiChunkRestore by lazy {
-        MultiChunkRestore(context, storagePlugin, fileRestore, streamCrypto, streamKey)
+        MultiChunkRestore(context, storagePluginGetter, fileRestore, streamCrypto, streamKey)
     }
 
     fun getBackupSnapshots(): Flow<SnapshotResult> = flow {

storage/lib/src/main/java/org/calyxos/backup/storage/restore/SingleChunkRestore.kt

@@ -13,9 +13,8 @@ import org.calyxos.backup.storage.crypto.StreamCrypto
 
 private const val TAG = "SingleChunkRestore"
 
-@Suppress("BlockingMethodInNonBlockingContext")
 internal class SingleChunkRestore(
-    storagePlugin: StoragePlugin,
+    storagePlugin: () -> StoragePlugin,
     fileRestore: FileRestore,
     streamCrypto: StreamCrypto,
     streamKey: ByteArray,

storage/lib/src/main/java/org/calyxos/backup/storage/restore/ZipChunkRestore.kt

@@ -17,9 +17,8 @@ import java.util.zip.ZipInputStream
 
 private const val TAG = "ZipChunkRestore"
 
-@Suppress("BlockingMethodInNonBlockingContext")
 internal class ZipChunkRestore(
-    storagePlugin: StoragePlugin,
+    storagePlugin: () -> StoragePlugin,
     fileRestore: FileRestore,
     streamCrypto: StreamCrypto,
     streamKey: ByteArray,

storage/lib/src/test/java/org/calyxos/backup/storage/BackupRestoreTest.kt

@@ -58,7 +58,6 @@ import java.io.OutputStream
 import javax.crypto.spec.SecretKeySpec
 import kotlin.random.Random
 
-@Suppress("BlockingMethodInNonBlockingContext")
 internal class BackupRestoreTest {
 
     @get:Rule
@@ -71,9 +70,10 @@ internal class BackupRestoreTest {
     private val contentResolver: ContentResolver = mockk()
 
     private val fileScanner: FileScanner = mockk()
+    private val pluginGetter: () -> StoragePlugin = mockk()
     private val plugin: StoragePlugin = mockk()
     private val fileRestore: FileRestore = mockk()
-    private val snapshotRetriever = SnapshotRetriever(plugin)
+    private val snapshotRetriever = SnapshotRetriever(pluginGetter)
     private val cacheRepopulater: ChunksCacheRepopulater = mockk()
 
     init {
@@ -84,6 +84,7 @@ internal class BackupRestoreTest {
 
         mockkStatic("org.calyxos.backup.storage.UriUtilsKt")
 
+        every { pluginGetter() } returns plugin
         every { db.getFilesCache() } returns filesCache
         every { db.getChunksCache() } returns chunksCache
         every { plugin.getMasterKey() } returns SecretKeySpec(
@@ -94,11 +95,11 @@ internal class BackupRestoreTest {
         every { context.contentResolver } returns contentResolver
     }
 
-    private val restore = Restore(context, plugin, snapshotRetriever, fileRestore)
+    private val restore = Restore(context, pluginGetter, snapshotRetriever, fileRestore)
 
     @Test
     fun testZipAndSingleRandom(): Unit = runBlocking {
-        val backup = Backup(context, db, fileScanner, plugin, cacheRepopulater)
+        val backup = Backup(context, db, fileScanner, pluginGetter, cacheRepopulater)
 
         val smallFileMBytes = Random.nextBytes(Random.nextInt(SMALL_FILE_SIZE_MAX))
         val smallFileM = getRandomMediaFile(smallFileMBytes.size)
@@ -235,7 +236,7 @@ internal class BackupRestoreTest {
 
     @Test
     fun testMultiChunks(): Unit = runBlocking {
-        val backup = Backup(context, db, fileScanner, plugin, cacheRepopulater, 4)
+        val backup = Backup(context, db, fileScanner, pluginGetter, cacheRepopulater, 4)
 
         val chunk1 = byteArrayOf(0x00, 0x01, 0x02, 0x03)
         val chunk2 = byteArrayOf(0x04, 0x05, 0x06, 0x07)

storage/lib/src/test/java/org/calyxos/backup/storage/backup/ChunksCacheRepopulaterTest.kt

@@ -26,18 +26,19 @@ import org.junit.Assert.assertTrue
 import org.junit.Test
 import kotlin.random.Random
 
-@Suppress("BlockingMethodInNonBlockingContext")
 internal class ChunksCacheRepopulaterTest {
 
     private val db: Db = mockk()
     private val chunksCache: ChunksCache = mockk()
+    private val pluginGetter: () -> StoragePlugin = mockk()
     private val plugin: StoragePlugin = mockk()
     private val snapshotRetriever: SnapshotRetriever = mockk()
     private val streamKey = "This is a backup key for testing".toByteArray()
-    private val cacheRepopulater = ChunksCacheRepopulater(db, plugin, snapshotRetriever)
+    private val cacheRepopulater = ChunksCacheRepopulater(db, pluginGetter, snapshotRetriever)
 
     init {
         mockLog()
+        every { pluginGetter() } returns plugin
         every { db.getChunksCache() } returns chunksCache
     }
 

storage/lib/src/test/java/org/calyxos/backup/storage/prune/PrunerTest.kt

@@ -32,11 +32,11 @@ import org.junit.Test
 import javax.crypto.spec.SecretKeySpec
 import kotlin.random.Random
 
-@Suppress("BlockingMethodInNonBlockingContext")
 internal class PrunerTest {
 
     private val db: Db = mockk()
     private val chunksCache: ChunksCache = mockk()
+    private val pluginGetter: () -> StoragePlugin = mockk()
     private val plugin: StoragePlugin = mockk()
     private val snapshotRetriever: SnapshotRetriever = mockk()
     private val retentionManager: RetentionManager = mockk()
@@ -46,12 +46,13 @@ internal class PrunerTest {
 
     init {
         mockLog(false)
+        every { pluginGetter() } returns plugin
         every { db.getChunksCache() } returns chunksCache
         every { plugin.getMasterKey() } returns masterKey
         every { streamCrypto.deriveStreamKey(masterKey) } returns streamKey
     }
 
-    private val pruner = Pruner(db, retentionManager, plugin, snapshotRetriever, streamCrypto)
+    private val pruner = Pruner(db, retentionManager, pluginGetter, snapshotRetriever, streamCrypto)
 
     @Test
     fun test() = runBlocking {