Don't re-install apps that are already installed and disable auto-restore

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

@@ -17,7 +17,6 @@ import android.os.ServiceManager.getService
 import android.os.StrictMode
 import android.os.UserHandle
 import android.os.UserManager
-import android.provider.Settings
 import androidx.work.ExistingPeriodicWorkPolicy.UPDATE
 import androidx.work.WorkManager
 import com.google.android.material.color.DynamicColors
@@ -148,6 +147,7 @@ open class App : Application() {
     private val metadataManager: MetadataManager by inject()
     private val backupManager: IBackupManager by inject()
     private val pluginManager: StoragePluginManager by inject()
+    private val backupStateManager: BackupStateManager by inject()
 
     /**
      * The responsibility for the current token was moved to the [SettingsManager]
@@ -168,7 +168,7 @@ open class App : Application() {
      * Introduced in the first half of 2024 and can be removed after a suitable migration period.
      */
     protected open fun migrateToOwnScheduling() {
-        if (!isFrameworkSchedulingEnabled()) { // already on own scheduling
+        if (!backupStateManager.isFrameworkSchedulingEnabled) { // already on own scheduling
             // fix things for removable drive users who had a job scheduled here before
             if (pluginManager.isOnRemovableDrive) AppBackupWorker.unschedule(applicationContext)
             return
@@ -184,10 +184,6 @@ open class App : Application() {
         }
     }
 
-    private fun isFrameworkSchedulingEnabled(): Boolean = Settings.Secure.getInt(
-        contentResolver, Settings.Secure.BACKUP_SCHEDULING_ENABLED, 1
-    ) == 1 // 1 means enabled which is the default
-
 }
 
 const val MAGIC_PACKAGE_MANAGER: String = PACKAGE_MANAGER_SENTINEL

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

@@ -6,6 +6,9 @@
 package com.stevesoltys.seedvault
 
 import android.content.Context
+import android.provider.Settings
+import android.provider.Settings.Secure.BACKUP_AUTO_RESTORE
+import android.provider.Settings.Secure.BACKUP_SCHEDULING_ENABLED
 import android.util.Log
 import androidx.work.WorkInfo.State.RUNNING
 import androidx.work.WorkManager
@@ -22,6 +25,7 @@ class BackupStateManager(
 ) {
 
     private val workManager = WorkManager.getInstance(context)
+    private val contentResolver = context.contentResolver
 
     val isBackupRunning: Flow<Boolean> = combine(
         flow = ConfigurableBackupTransportService.isRunning,
@@ -37,4 +41,10 @@ class BackupStateManager(
         appBackupRunning || filesBackupRunning || workInfoState == RUNNING
     }
 
+    val isAutoRestoreEnabled: Boolean
+        get() = Settings.Secure.getInt(contentResolver, BACKUP_AUTO_RESTORE, 1) == 1
+
+    val isFrameworkSchedulingEnabled: Boolean
+        get() = Settings.Secure.getInt(contentResolver, BACKUP_SCHEDULING_ENABLED, 1) == 1
+
 }

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

@@ -5,11 +5,13 @@
 
 package com.stevesoltys.seedvault.restore.install
 
+import android.app.backup.IBackupManager
 import android.content.Context
 import android.content.pm.PackageManager
 import android.content.pm.PackageManager.GET_SIGNATURES
 import android.content.pm.PackageManager.GET_SIGNING_CERTIFICATES
 import android.util.Log
+import com.stevesoltys.seedvault.BackupStateManager
 import com.stevesoltys.seedvault.MAGIC_PACKAGE_MANAGER
 import com.stevesoltys.seedvault.crypto.Crypto
 import com.stevesoltys.seedvault.metadata.ApkSplit
@@ -38,6 +40,8 @@ private val TAG = ApkRestore::class.java.simpleName
 
 internal class ApkRestore(
     private val context: Context,
+    private val backupManager: IBackupManager,
+    private val backupStateManager: BackupStateManager,
     private val pluginManager: StoragePluginManager,
     @Suppress("Deprecation")
     private val legacyStoragePlugin: LegacyStoragePlugin,
@@ -81,14 +85,33 @@ internal class ApkRestore(
             return
         }
         mInstallResult.value = InstallResult(packages)
+        val autoRestore = backupStateManager.isAutoRestoreEnabled
+        try {
+            // disable auto-restore before installing apps, if it was enabled before
+            if (autoRestore) backupManager.setAutoRestore(false)
+            reInstallApps(backup, packages.asIterable().reversed())
+        } finally {
+            // re-enable auto-restore, if it was enabled before
+            if (autoRestore) backupManager.setAutoRestore(true)
+        }
+        mInstallResult.update { it.copy(isFinished = true) }
+    }
 
+    private suspend fun reInstallApps(
+        backup: RestorableBackup,
+        packages: List<Map.Entry<String, ApkInstallResult>>,
+    ) {
         // re-install individual packages and emit updates (start from last and work your way up)
-        for ((packageName, apkInstallResult) in packages.asIterable().reversed()) {
+        for ((packageName, apkInstallResult) in packages) {
             try {
-                if (apkInstallResult.metadata.hasApk()) {
-                    restore(backup, packageName, apkInstallResult.metadata)
-                } else {
+                if (isInstalled(packageName, apkInstallResult.metadata)) {
+                    mInstallResult.update { result ->
+                        result.update(packageName) { it.copy(state = SUCCEEDED) }
+                    }
+                } else if (!apkInstallResult.metadata.hasApk()) { // no APK available for install
                     mInstallResult.update { it.fail(packageName) }
+                } else {
+                    restore(backup, packageName, apkInstallResult.metadata)
                 }
             } catch (e: IOException) {
                 Log.e(TAG, "Error re-installing APK for $packageName.", e)
@@ -104,7 +127,23 @@ internal class ApkRestore(
                 mInstallResult.update { it.fail(packageName) }
             }
         }
-        mInstallResult.update { it.copy(isFinished = true) }
+    }
+
+    @Throws(SecurityException::class)
+    private fun isInstalled(packageName: String, metadata: PackageMetadata): Boolean {
+        @Suppress("DEPRECATION") // GET_SIGNATURES is needed even though deprecated
+        val flags = GET_SIGNING_CERTIFICATES or GET_SIGNATURES
+        val packageInfo = try {
+            pm.getPackageInfo(packageName, flags)
+        } catch (e: PackageManager.NameNotFoundException) {
+            null
+        } ?: return false
+        val signatures = metadata.signatures
+        if (signatures != null && signatures != packageInfo.signingInfo.getSignatures()) {
+            // this will get caught and flag app as failed, could receive dedicated handling later
+            throw SecurityException("Signature mismatch for $packageName")
+        }
+        return packageInfo.longVersionCode >= (metadata.version ?: 0)
     }
 
     @Suppress("ThrowsCount")

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

@@ -14,7 +14,7 @@ val installModule = module {
     factory { DeviceInfo(androidContext()) }
     factory { ApkSplitCompatibilityChecker(get()) }
     factory {
-        ApkRestore(androidContext(), get(), get(), get(), get(), get()) {
+        ApkRestore(androidContext(), get(), get(), get(), get(), get(), get(), get()) {
             androidContext().getSystemService(UserManager::class.java)!!.isAllowedToInstallApks()
         }
     }

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

@@ -10,8 +10,6 @@ import android.content.Intent
 import android.os.Bundle
 import android.os.PowerManager
 import android.os.RemoteException
-import android.provider.Settings
-import android.provider.Settings.Secure.BACKUP_AUTO_RESTORE
 import android.util.Log
 import android.view.Menu
 import android.view.MenuInflater
@@ -25,6 +23,7 @@ import androidx.preference.PreferenceFragmentCompat
 import androidx.preference.TwoStatePreference
 import androidx.work.WorkInfo
 import com.google.android.material.dialog.MaterialAlertDialogBuilder
+import com.stevesoltys.seedvault.BackupStateManager
 import com.stevesoltys.seedvault.R
 import com.stevesoltys.seedvault.permitDiskReads
 import com.stevesoltys.seedvault.plugins.StoragePluginManager
@@ -41,6 +40,7 @@ class SettingsFragment : PreferenceFragmentCompat() {
 
     private val viewModel: SettingsViewModel by sharedViewModel()
     private val storagePluginManager: StoragePluginManager by inject()
+    private val backupStateManager: BackupStateManager by inject()
     private val backupManager: IBackupManager by inject()
 
     private lateinit var backup: TwoStatePreference
@@ -251,7 +251,7 @@ class SettingsFragment : PreferenceFragmentCompat() {
 
     private fun setAutoRestoreState() {
         activity?.contentResolver?.let {
-            autoRestore.isChecked = Settings.Secure.getInt(it, BACKUP_AUTO_RESTORE, 1) == 1
+            autoRestore.isChecked = backupStateManager.isAutoRestoreEnabled
         }
         val storage = this.storageProperties
         if (storage?.isUsb == true) {

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

@@ -5,12 +5,15 @@
 
 package com.stevesoltys.seedvault.restore.install
 
+import android.app.backup.IBackupManager
 import android.content.Context
 import android.content.pm.PackageManager
+import android.content.pm.PackageManager.NameNotFoundException
 import android.content.pm.Signature
 import android.graphics.drawable.Drawable
 import android.util.PackageUtils
 import app.cash.turbine.test
+import com.stevesoltys.seedvault.BackupStateManager
 import com.stevesoltys.seedvault.assertReadEquals
 import com.stevesoltys.seedvault.getRandomString
 import com.stevesoltys.seedvault.metadata.ApkSplit
@@ -56,6 +59,8 @@ internal class ApkBackupRestoreTest : TransportTest() {
     }
 
     private val storagePluginManager: StoragePluginManager = mockk()
+    private val backupManager: IBackupManager = mockk()
+    private val backupStateManager: BackupStateManager = mockk()
 
     @Suppress("Deprecation")
     private val legacyStoragePlugin: LegacyStoragePlugin = mockk()
@@ -67,6 +72,8 @@ internal class ApkBackupRestoreTest : TransportTest() {
     private val apkBackup = ApkBackup(pm, crypto, settingsManager, metadataManager)
     private val apkRestore: ApkRestore = ApkRestore(
         context = strictContext,
+        backupManager = backupManager,
+        backupStateManager = backupStateManager,
         pluginManager = storagePluginManager,
         legacyStoragePlugin = legacyStoragePlugin,
         crypto = crypto,
@@ -145,6 +152,8 @@ internal class ApkBackupRestoreTest : TransportTest() {
         val cacheFiles = slot<List<File>>()
 
         every { installRestriction.isAllowedToInstallApks() } returns true
+        every { backupStateManager.isAutoRestoreEnabled } returns false
+        every { pm.getPackageInfo(packageName, any<Int>()) } throws NameNotFoundException()
         every { strictContext.cacheDir } returns tmpFile
         every { crypto.getNameForApk(salt, packageName, "") } returns name
         coEvery { storagePlugin.getInputStream(token, name) } returns inputStream