feat: backup/restore flow (#81)

Co-authored-by: Justin Hernandez <transphorm@gmail.com>

app/android/app/src/main/AndroidManifest.xml

@@ -3,8 +3,6 @@
   xmlns:tools="http://schemas.android.com/tools"
   
 >
-          
-
     <uses-permission android:name="android.permission.INTERNET" />
     <uses-permission android:name="android.permission.CAMERA" />
     <uses-permission android:name="android.permission.ACCESS_SURFACE_FLINGER" />
@@ -18,7 +16,6 @@
       android:label="@string/app_name"
       android:icon="@mipmap/ic_launcher"
       android:roundIcon="@mipmap/ic_launcher"
-      android:allowBackup="false"
       tools:replace="android:allowBackup, android:icon, android:roundIcon, android:name"
       android:theme="@style/AppTheme"
       android:supportsRtl="true">
@@ -45,3 +42,11 @@
       </activity>
     </application>
 </manifest>
+
+
+<!--
+TODO: add this back to <application />
+    android:allowBackup="true"
+    android:backupInForeground="true"
+    android:dataExtractionRules="@xml/backup_rules"
+-->

app/android/app/src/main/java/com/proofofpassportapp/BackupModule.kt

@@ -0,0 +1,25 @@
+package com.proofofpassportapp
+
+import android.app.backup.BackupManager
+import com.facebook.react.bridge.Promise
+import com.facebook.react.bridge.ReactApplicationContext
+import com.facebook.react.bridge.ReactContextBaseJavaModule
+import com.facebook.react.bridge.ReactMethod
+
+class BackupModule(reactContext: ReactApplicationContext): ReactContextBaseJavaModule(reactContext) {
+    override fun getName() = "BackupModule"
+
+    @ReactMethod
+    fun backupNow(promise: Promise) {
+        // https://developer.android.com/identity/data/keyvaluebackup#RequestingBackup
+        BackupManager.dataChanged(BuildConfig.APPLICATION_ID)
+        promise.resolve(null)
+    }
+
+    @ReactMethod
+    fun restoreNow(promise: Promise) {
+        // noop
+        // https://developer.android.com/identity/data/keyvaluebackup#RequestingRestore
+        promise.resolve(null)
+    }
+}

app/android/app/src/main/java/com/proofofpassportapp/BackupPackage.kt

@@ -0,0 +1,19 @@
+package com.proofofpassportapp
+
+import com.facebook.react.ReactPackage
+import com.facebook.react.bridge.NativeModule
+import com.facebook.react.bridge.ReactApplicationContext
+import com.facebook.react.uimanager.ViewManager
+
+class BackupPackage : ReactPackage {
+    override fun createViewManagers(reactContext: ReactApplicationContext): List<ViewManager<*, *>> {
+        return emptyList()
+    }
+
+    override fun createNativeModules(reactContext: ReactApplicationContext): List<NativeModule> {
+        return listOf(
+            BackupModule(reactContext)
+        )
+    }
+
+}

app/android/app/src/main/java/com/proofofpassportapp/MainApplication.kt

@@ -8,10 +8,6 @@ import com.facebook.react.ReactPackage
 import com.facebook.react.defaults.DefaultNewArchitectureEntryPoint
 import com.facebook.react.defaults.DefaultReactNativeHost
 import com.facebook.soloader.SoLoader
-import com.proofofpassportapp.CameraActivityPackage
-import io.tradle.nfc.RNPassportReaderPackage
-import com.rnfs.RNFSPackage
-import com.proofofpassportapp.QRCodeScannerPackage
 
 class MainApplication : Application(), ReactApplication {
 
@@ -23,6 +19,7 @@ class MainApplication : Application(), ReactApplication {
               // add(MyReactNativePackage())
               add(CameraActivityPackage())
               add(QRCodeScannerPackage())
+              add(BackupPackage())
             }
 
         override fun getJSMainModuleName(): String = "index"

app/android/app/src/main/res/xml/backup_rules.xml

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<data-extraction-rules>
+  <cloud-backup>
+    <include domain="file" path="."
+              requireFlags="clientSideEncryption" />
+  </cloud-backup>
+  <device-transfer>
+  </device-transfer>
+</data-extraction-rules>