Prepare Amzon store release

app/build.gradle

@@ -132,6 +132,7 @@ android {
             dimension "all"
             buildConfigField "boolean", "BETA_RELEASE", "true"
             buildConfigField "boolean", "PLAY_STORE_RELEASE", "false"
+            buildConfigField "boolean", "AMAZON_RELEASE", "false"
             buildConfigField "String", "PRO_FEATURES_URI", "\"https://email.faircode.eu/donate/\""
             buildConfigField "String", "CHANGELOG", "\"https://github.com/M66B/FairEmail/releases/\""
             buildConfigField "String", "GITHUB_LATEST_API", "\"https://api.github.com/repos/M66B/FairEmail/releases/latest\""
@@ -142,6 +143,7 @@ android {
             dimension "all"
             buildConfigField "boolean", "BETA_RELEASE", "true"
             buildConfigField "boolean", "PLAY_STORE_RELEASE", "false"
+            buildConfigField "boolean", "AMAZON_RELEASE", "false"
             buildConfigField "String", "PRO_FEATURES_URI", "\"https://email.faircode.eu/donate/\""
             buildConfigField "String", "CHANGELOG", "\"https://github.com/M66B/FairEmail/releases/\""
             buildConfigField "String", "GITHUB_LATEST_API", "\"https://api.github.com/repos/M66B/FairEmail/releases/latest\""
@@ -153,6 +155,19 @@ android {
             //minSdkVersion 23
             buildConfigField "boolean", "BETA_RELEASE", "true"
             buildConfigField "boolean", "PLAY_STORE_RELEASE", "true"
+            buildConfigField "boolean", "AMAZON_RELEASE", "false"
+            buildConfigField "String", "PRO_FEATURES_URI", "\"https://email.faircode.eu/#pro\""
+            buildConfigField "String", "CHANGELOG", "\"\""
+            buildConfigField "String", "GITHUB_LATEST_API", "\"\""
+            buildConfigField "String", "GITHUB_LATEST_URI", "\"\""
+            buildConfigField "String", "GRAVATAR_URI", "\"\""
+        }
+        amazon {
+            dimension "all"
+            //minSdkVersion 23
+            buildConfigField "boolean", "BETA_RELEASE", "true"
+            buildConfigField "boolean", "PLAY_STORE_RELEASE", "false"
+            buildConfigField "boolean", "AMAZON_RELEASE", "true"
             buildConfigField "String", "PRO_FEATURES_URI", "\"https://email.faircode.eu/#pro\""
             buildConfigField "String", "CHANGELOG", "\"\""
             buildConfigField "String", "GITHUB_LATEST_API", "\"\""
@@ -166,7 +181,7 @@ android {
         // Builds: release, debug
         // Flavors: github, fdroid, play
         if (variant.buildType.name == "debug" &&
-                (flavors.contains("fdroid") || flavors.contains("play"))) {
+                (flavors.contains("fdroid") || flavors.contains("play") || flavors.contains("_amazon"))) {
             setIgnore(true)
         }
     }
@@ -236,7 +251,7 @@ configurations.all {
 }
 
 dependencies {
-    implementation fileTree(dir: 'libs', include: ['*.jar'])
+    //implementation fileTree(dir: 'libs', include: ['*.jar'])
 
     def startup_version = "1.1.0-beta01"
     def annotation_version = "1.1.0"
@@ -380,6 +395,9 @@ dependencies {
     githubImplementation "com.android.billingclient:billing:$billingclient_version"
     playImplementation "com.android.billingclient:billing:$billingclient_version"
 
+    // https://developer.amazon.com/docs/in-app-purchasing/iap-get-started.html
+    amazonImplementation files('lib/in-app-purchasing-2.0.76.jar')
+
     // https://javaee.github.io/javamail/
     // https://projects.eclipse.org/projects/ee4j.javamail
     // https://mvnrepository.com/artifact/com.sun.mail

app/proguard-rules.pro

@@ -132,3 +132,8 @@
 -keep class org.commonmark.** {*;}
 -keepnames class io.noties.markwon.** {*;}
 -keepnames class org.commonmark.** {*;}
+
+#Amazon IAP
+-dontwarn com.amazon.**
+-keep class com.amazon.** {*;}
+-keepattributes *Annotation*

app/src/amazon/AndroidManifest.xml

@@ -0,0 +1,479 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools"
+    package="eu.faircode.email"
+    android:installLocation="internalOnly">
+
+    <uses-permission android:name="android.permission.INTERNET" />
+    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
+    <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
+    <uses-permission android:name="android.permission.READ_CONTACTS" />
+    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
+    <uses-permission android:name="android.permission.SCHEDULE_EXACT_ALARM" />
+    <uses-permission android:name="android.permission.WAKE_LOCK" />
+    <uses-permission android:name="android.permission.USE_BIOMETRIC" />
+
+    <uses-permission android:name="com.android.vending.BILLING" />
+
+    <!-- OAuth -->
+    <uses-permission android:name="android.permission.GET_ACCOUNTS" />
+    <uses-permission
+        android:name="android.permission.USE_CREDENTIALS"
+        android:maxSdkVersion="22" />
+    <uses-permission
+        android:name="android.permission.READ_PROFILE"
+        android:maxSdkVersion="22" />
+
+    <!-- https://developer.android.com/guide/topics/manifest/uses-feature-element#features-reference -->
+    <uses-feature
+        android:name="android.software.app_widgets"
+        android:required="false" />
+    <!--uses-feature
+        android:name="android.software.webview"
+        android:required="false" /-->
+    <uses-feature
+        android:name="android.hardware.camera"
+        android:required="false" />
+    <uses-feature
+        android:name="android.hardware.fingerprint"
+        android:required="false" />
+
+    <!-- Android 11: https://developer.android.com/preview/privacy/package-visibility -->
+    <queries>
+        <!-- Customtabs -->
+        <!-- https://developers.google.com/web/updates/2020/07/custom-tabs-android-11#detecting_browsers_that_support_custom_tabs -->
+        <intent>
+            <action android:name="android.support.customtabs.action.CustomTabsService" />
+        </intent>
+
+        <intent>
+            <action android:name="android.intent.action.INSERT" />
+        </intent>
+
+        <intent>
+            <action android:name="android.intent.action.GET_CONTENT" />
+            <category android:name="android.intent.category.OPENABLE" />
+            <data android:mimeType="*/*" />
+        </intent>
+
+        <intent>
+            <action android:name="android.media.action.IMAGE_CAPTURE" />
+        </intent>
+
+        <intent>
+            <action android:name="android.provider.MediaStore.RECORD_SOUND" />
+        </intent>
+
+        <package android:name="com.android.vending" />
+
+        <package android:name="org.sufficientlysecure.keychain" />
+        <package android:name="org.sufficientlysecure.keychain.debug" />
+
+        <intent>
+            <action android:name="org.openintents.openpgp.IOpenPgpService2" />
+        </intent>
+
+        <!-- https://android-developers.googleblog.com/2015/10/in-app-translations-in-android.html -->
+        <intent>
+            <action android:name="android.intent.action.PROCESS_TEXT" />
+            <data android:mimeType="text/plain" />
+        </intent>
+
+        <package android:name="com.google.android.tts" />
+
+        <package android:name="com.amazon.sdktestclient" />
+    </queries>
+
+    <application
+        android:name=".ApplicationEx"
+        android:allowBackup="false"
+        android:appCategory="productivity"
+        android:forceDarkAllowed="false"
+        android:icon="@mipmap/ic_launcher"
+        android:label="@string/app_name"
+        android:networkSecurityConfig="@xml/network_security_config"
+        android:requestLegacyExternalStorage="true"
+        android:resizeableActivity="true"
+        android:roundIcon="@mipmap/ic_launcher_round"
+        android:supportsRtl="true"
+        android:theme="@style/AppThemeBlueOrangeLight">
+        <!-- https://developer.samsung.com/samsung-dex/modify-optimizing.html -->
+
+        <!-- https://developer.android.com/guide/webapps/managing-webview#metrics -->
+        <meta-data
+            android:name="android.webkit.WebView.MetricsOptOut"
+            android:value="true" />
+        <meta-data
+            android:name="android.webkit.WebView.EnableSafeBrowsing"
+            android:value="false" />
+        <meta-data
+            android:name="android.allow_multiple_resumed_activities"
+            android:value="true" />
+        <meta-data
+            android:name="com.google.android.gms.car.application"
+            android:resource="@xml/car"
+            tools:node="remove" />
+        <!-- https://play.google.com/about/auto/developer-distribution-agreement-addendum/ -->
+        <meta-data
+            android:name="com.bugsnag.android.API_KEY"
+            android:value="9d2d57476a0614974449a3ec33f2604a" />
+
+        <activity
+            android:name=".ActivityMain"
+            android:excludeFromRecents="true"
+            android:exported="true"
+            android:launchMode="singleInstance"
+            android:theme="@style/Theme.AppCompat.Translucent">
+
+            <meta-data
+                android:name="android.app.shortcuts"
+                android:resource="@xml/shortcuts" />
+            <meta-data
+                android:name="android.service.chooser.chooser_target_service"
+                android:value="androidx.sharetarget.ChooserTargetServiceCompat" />
+
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+
+            <intent-filter>
+                <action android:name="${applicationId}.REFRESH" />
+                <category android:name="android.intent.category.DEFAULT" />
+            </intent-filter>
+
+            <intent-filter>
+                <action android:name="android.intent.action.VIEW" />
+
+                <category android:name="android.intent.category.DEFAULT" />
+                <category android:name="android.intent.category.BROWSABLE" />
+
+                <data android:scheme="message" />
+                <data android:host="${applicationId}" />
+            </intent-filter>
+        </activity>
+
+        <activity
+            android:name=".ActivitySetup"
+            android:exported="false"
+            android:launchMode="singleTask"
+            android:parentActivityName=".ActivityMain" />
+
+        <activity
+            android:name=".ActivitySignature"
+            android:exported="false"
+            android:launchMode="singleTask"
+            android:parentActivityName=".ActivitySetup" />
+
+        <activity
+            android:name=".ActivityWidget"
+            android:exported="true">
+
+            <intent-filter>
+                <action android:name="android.appwidget.action.APPWIDGET_CONFIGURE" />
+            </intent-filter>
+        </activity>
+
+        <activity
+            android:name=".ActivityWidgetSync"
+            android:exported="true">
+
+            <intent-filter>
+                <action android:name="android.appwidget.action.APPWIDGET_CONFIGURE" />
+            </intent-filter>
+        </activity>
+
+        <activity
+            android:name=".ActivityWidgetUnified"
+            android:exported="true">
+
+            <intent-filter>
+                <action android:name="android.appwidget.action.APPWIDGET_CONFIGURE" />
+            </intent-filter>
+        </activity>
+
+        <activity
+            android:name=".ActivityView"
+            android:exported="false"
+            android:launchMode="singleTask"
+            android:parentActivityName=".ActivityMain" />
+
+        <activity
+            android:name=".ActivitySearch"
+            android:enabled="false"
+            android:excludeFromRecents="true"
+            android:exported="true"
+            android:icon="@mipmap/ic_launcher"
+            android:label="@string/app_search"
+            android:launchMode="singleTask"
+            android:theme="@style/Theme.AppCompat.Translucent">
+
+            <intent-filter>
+                <action android:name="android.intent.action.PROCESS_TEXT" />
+                <category android:name="android.intent.category.DEFAULT" />
+                <data android:mimeType="text/plain" />
+            </intent-filter>
+        </activity>
+
+        <activity
+            android:name=".ActivityCompose"
+            android:exported="true"
+            android:launchMode="singleTask"
+            android:parentActivityName=".ActivityView">
+            <intent-filter>
+                <action android:name="android.intent.action.VIEW" />
+
+                <category android:name="android.intent.category.DEFAULT" />
+                <category android:name="android.intent.category.BROWSABLE" />
+
+                <data android:scheme="mailto" />
+            </intent-filter>
+
+            <intent-filter>
+                <action android:name="android.intent.action.SENDTO" />
+                <category android:name="android.intent.category.DEFAULT" />
+                <data android:scheme="mailto" />
+            </intent-filter>
+
+            <intent-filter>
+                <action android:name="android.intent.action.SEND" />
+                <action android:name="android.intent.action.SEND_MULTIPLE" />
+
+                <category android:name="android.intent.category.DEFAULT" />
+                <data android:mimeType="*/*" />
+            </intent-filter>
+        </activity>
+
+        <activity
+            android:name=".ActivityEML"
+            android:exported="true"
+            android:icon="@mipmap/ic_launcher"
+            android:launchMode="singleTask">
+
+            <intent-filter>
+                <action android:name="android.intent.action.VIEW" />
+
+                <category android:name="android.intent.category.BROWSABLE" />
+                <category android:name="android.intent.category.DEFAULT" />
+
+                <data android:scheme="content" />
+                <data android:mimeType="message/rfc822" />
+                <data android:host="*" />
+            </intent-filter>
+
+            <intent-filter>
+                <action android:name="android.intent.action.VIEW" />
+
+                <category android:name="android.intent.category.BROWSABLE" />
+                <category android:name="android.intent.category.DEFAULT" />
+
+                <data android:scheme="content" />
+                <data android:mimeType="*/*" />
+                <data android:host="*" />
+                <data android:pathPattern=".*\\.eml" />
+                <data android:pathPattern=".*\\..*\\.eml" />
+                <data android:pathPattern=".*\\..*\\..*\\.eml" />
+                <data android:pathPattern=".*\\..*\\..*\\..*\\.eml" />
+                <data android:pathPattern=".*\\..*\\..*\\..*\\..*\\.eml" />
+            </intent-filter>
+        </activity>
+
+        <activity
+            android:name=".ActivityDSN"
+            android:exported="true"
+            android:icon="@mipmap/ic_launcher"
+            android:launchMode="singleTask">
+
+            <intent-filter>
+                <action android:name="android.intent.action.VIEW" />
+
+                <category android:name="android.intent.category.BROWSABLE" />
+                <category android:name="android.intent.category.DEFAULT" />
+
+                <data android:scheme="content" />
+                <data android:mimeType="message/delivery-status" />
+                <data android:mimeType="message/disposition-notification" />
+                <data android:mimeType="text/rfc822-headers" />
+                <data android:host="*" />
+            </intent-filter>
+        </activity>
+
+        <activity
+            android:name=".ActivityBilling"
+            android:exported="false"
+            android:icon="@mipmap/ic_launcher"
+            android:launchMode="singleTask" />
+
+        <activity
+            android:name="net.openid.appauth.RedirectUriReceiverActivity"
+            android:exported="true"
+            tools:node="replace">
+            <intent-filter android:autoVerify="true">
+                <action android:name="android.intent.action.VIEW" />
+
+                <category android:name="android.intent.category.DEFAULT" />
+                <category android:name="android.intent.category.BROWSABLE" />
+
+                <data
+                    android:host="oauth.faircode.eu"
+                    android:scheme="https" />
+            </intent-filter>
+
+            <intent-filter>
+                <action android:name="android.intent.action.VIEW" />
+
+                <category android:name="android.intent.category.DEFAULT" />
+                <category android:name="android.intent.category.BROWSABLE" />
+
+                <data android:scheme="eu.faircode.email" />
+            </intent-filter>
+        </activity>
+
+        <service
+            android:name=".ServiceSynchronize"
+            android:exported="false"
+            android:foregroundServiceType="dataSync" />
+
+        <service
+            android:name=".ServiceSend"
+            android:exported="false"
+            android:foregroundServiceType="dataSync" />
+
+        <service
+            android:name=".ServiceUI"
+            android:exported="false" />
+
+        <service
+            android:name=".ServiceExternal"
+            android:exported="true"
+            android:foregroundServiceType="dataSync">
+
+            <intent-filter>
+                <action android:name="${applicationId}.POLL" />
+                <action android:name="${applicationId}.ENABLE" />
+                <action android:name="${applicationId}.DISABLE" />
+                <action android:name="${applicationId}.INTERVAL" />
+                <action android:name="${applicationId}.DISCONNECT.ME" />
+            </intent-filter>
+        </service>
+
+        <service
+            android:name=".ServiceTileSynchronize"
+            android:exported="true"
+            android:icon="@drawable/twotone_sync_disabled_24"
+            android:label="@string/app_name"
+            android:permission="android.permission.BIND_QUICK_SETTINGS_TILE">
+
+            <intent-filter>
+                <action android:name="android.service.quicksettings.action.QS_TILE" />
+            </intent-filter>
+        </service>
+
+        <service
+            android:name=".ServiceTileUnseen"
+            android:exported="true"
+            android:icon="@drawable/twotone_mail_outline_24"
+            android:label="@string/tile_unseen"
+            android:permission="android.permission.BIND_QUICK_SETTINGS_TILE">
+
+            <intent-filter>
+                <action android:name="android.service.quicksettings.action.QS_TILE" />
+            </intent-filter>
+        </service>
+
+        <service
+            android:name=".ServicePowerControl"
+            android:enabled="false"
+            android:exported="true"
+            android:label="@string/app_name"
+            android:permission="android.permission.BIND_CONTROLS">
+            <intent-filter>
+                <action android:name="android.service.controls.ControlsProviderService" />
+            </intent-filter>
+        </service>
+
+        <provider
+            android:name="androidx.core.content.FileProvider"
+            android:authorities="${applicationId}"
+            android:exported="false"
+            android:grantUriPermissions="true">
+
+            <meta-data
+                android:name="android.support.FILE_PROVIDER_PATHS"
+                android:resource="@xml/fileprovider_paths" />
+        </provider>
+
+        <receiver
+            android:name=".Widget"
+            android:exported="true"
+            android:label="@string/title_widget_title_count">
+
+            <meta-data
+                android:name="android.appwidget.provider"
+                android:resource="@xml/widget" />
+
+            <intent-filter>
+                <action android:name="android.appwidget.action.APPWIDGET_UPDATE" />
+            </intent-filter>
+        </receiver>
+
+        <receiver
+            android:name=".WidgetUnified"
+            android:exported="true"
+            android:label="@string/title_widget_title_list">
+
+            <meta-data
+                android:name="android.appwidget.provider"
+                android:resource="@xml/widget_unified" />
+
+            <intent-filter>
+                <action android:name="android.appwidget.action.APPWIDGET_UPDATE" />
+            </intent-filter>
+        </receiver>
+
+        <receiver
+            android:name=".WidgetSync"
+            android:exported="true"
+            android:label="@string/title_widget_title_sync">
+
+            <meta-data
+                android:name="android.appwidget.provider"
+                android:resource="@xml/widget_sync" />
+
+            <intent-filter>
+                <action android:name="android.appwidget.action.APPWIDGET_UPDATE" />
+            </intent-filter>
+        </receiver>
+
+        <service
+            android:name="WidgetUnifiedService"
+            android:exported="true"
+            android:permission="android.permission.BIND_REMOTEVIEWS" />
+
+        <receiver
+            android:name=".ReceiverAutoStart"
+            android:exported="true">
+
+            <intent-filter>
+                <action android:name="android.intent.action.BOOT_COMPLETED" />
+            </intent-filter>
+
+            <intent-filter>
+                <action android:name="android.intent.action.MY_PACKAGE_REPLACED" />
+            </intent-filter>
+
+            <intent-filter>
+                <action android:name="android.app.action.SCHEDULE_EXACT_ALARM_PERMISSION_STATE_CHANGED" />
+            </intent-filter>
+        </receiver>
+
+        <receiver
+            android:name="com.amazon.device.iap.ResponseReceiver"
+            android:permission="com.amazon.inapp.purchasing.Permission.NOTIFY">
+            <intent-filter>
+                <action android:name="com.amazon.inapp.purchasing.NOTIFY" />
+            </intent-filter>
+        </receiver>
+    </application>
+</manifest>

app/src/amazon/java/eu/faircode/email/ActivityBilling.java

@@ -0,0 +1,368 @@
+package eu.faircode.email;
+
+/*
+    This file is part of FairEmail.
+
+    FairEmail is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    FairEmail is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with FairEmail.  If not, see <http://www.gnu.org/licenses/>.
+
+    Copyright 2018-2021 by Marcel Bokhorst (M66B)
+*/
+
+import android.annotation.SuppressLint;
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.content.IntentFilter;
+import android.content.SharedPreferences;
+import android.net.Uri;
+import android.os.Bundle;
+import android.provider.Settings;
+import android.text.TextUtils;
+
+import androidx.annotation.NonNull;
+import androidx.fragment.app.FragmentManager;
+import androidx.fragment.app.FragmentTransaction;
+import androidx.lifecycle.Lifecycle;
+import androidx.lifecycle.LifecycleObserver;
+import androidx.lifecycle.LifecycleOwner;
+import androidx.lifecycle.OnLifecycleEvent;
+import androidx.localbroadcastmanager.content.LocalBroadcastManager;
+import androidx.preference.PreferenceManager;
+
+import com.amazon.device.iap.PurchasingListener;
+import com.amazon.device.iap.PurchasingService;
+import com.amazon.device.iap.model.FulfillmentResult;
+import com.amazon.device.iap.model.Product;
+import com.amazon.device.iap.model.ProductDataResponse;
+import com.amazon.device.iap.model.PurchaseResponse;
+import com.amazon.device.iap.model.PurchaseUpdatesResponse;
+import com.amazon.device.iap.model.Receipt;
+import com.amazon.device.iap.model.RequestId;
+import com.amazon.device.iap.model.UserDataResponse;
+
+import java.security.NoSuchAlgorithmException;
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+public class ActivityBilling extends ActivityBase implements PurchasingListener, FragmentManager.OnBackStackChangedListener {
+    private boolean standalone = false;
+    private String currentUserId;
+    private String currentMarketplace;
+    private List<IBillingListener> listeners = new ArrayList<>();
+
+    static final String ACTION_PURCHASE = BuildConfig.APPLICATION_ID + ".ACTION_PURCHASE";
+    static final String ACTION_PURCHASE_CONSUME = BuildConfig.APPLICATION_ID + ".ACTION_PURCHASE_CONSUME";
+    static final String ACTION_PURCHASE_ERROR = BuildConfig.APPLICATION_ID + ".ACTION_PURCHASE_ERROR";
+
+    @Override
+    @SuppressLint("MissingSuperCall")
+    protected void onCreate(Bundle savedInstanceState) {
+        onCreate(savedInstanceState, true);
+    }
+
+    protected void onCreate(Bundle savedInstanceState, boolean standalone) {
+        super.onCreate(savedInstanceState);
+
+        this.standalone = standalone;
+
+        if (standalone) {
+            setContentView(R.layout.activity_billing);
+
+            FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
+            fragmentTransaction.replace(R.id.content_frame, new FragmentPro()).addToBackStack("pro");
+            fragmentTransaction.commit();
+
+            getSupportActionBar().setDisplayHomeAsUpEnabled(true);
+
+            getSupportFragmentManager().addOnBackStackChangedListener(this);
+        }
+
+        if (Helper.isAmazonInstall() || isTesting(this)) {
+            Log.i("IAB start sandbox=" + PurchasingService.IS_SANDBOX_MODE);
+            PurchasingService.registerListener(this.getApplicationContext(), this);
+        }
+    }
+
+    @Override
+    public void onBackStackChanged() {
+        if (getSupportFragmentManager().getBackStackEntryCount() == 0)
+            finish();
+    }
+
+    @Override
+    protected void onResume() {
+        super.onResume();
+
+        if (standalone) {
+            LocalBroadcastManager lbm = LocalBroadcastManager.getInstance(this);
+            IntentFilter iff = new IntentFilter();
+            iff.addAction(ACTION_PURCHASE);
+            iff.addAction(ACTION_PURCHASE_CONSUME);
+            iff.addAction(ACTION_PURCHASE_ERROR);
+            lbm.registerReceiver(receiver, iff);
+        }
+
+        update();
+    }
+
+    @Override
+    protected void onPause() {
+        super.onPause();
+
+        if (standalone) {
+            LocalBroadcastManager lbm = LocalBroadcastManager.getInstance(this);
+            lbm.unregisterReceiver(receiver);
+        }
+    }
+
+    @Override
+    protected void onDestroy() {
+        super.onDestroy();
+    }
+
+    @NonNull
+    static String getSkuPro() {
+        return BuildConfig.APPLICATION_ID.replace(".debug", "") + ".pro";
+    }
+
+    static boolean isTesting(Context context) {
+        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
+        return (BuildConfig.DEBUG && prefs.getBoolean("test_iab", false));
+    }
+
+    private static String getChallenge(Context context) throws NoSuchAlgorithmException {
+        String android_id = Settings.Secure.getString(context.getContentResolver(), Settings.Secure.ANDROID_ID);
+        return Helper.sha256(android_id);
+    }
+
+    private static String getResponse(Context context) throws NoSuchAlgorithmException {
+        return Helper.sha256(BuildConfig.APPLICATION_ID.replace(".debug", "") + getChallenge(context));
+    }
+
+    static boolean activatePro(Context context, Uri data) throws NoSuchAlgorithmException {
+        String response = data.getQueryParameter("response");
+        return activatePro(context, response);
+    }
+
+    static boolean activatePro(Context context, String response) throws NoSuchAlgorithmException {
+        String challenge = getChallenge(context);
+        Log.i("IAB challenge=" + challenge);
+        Log.i("IAB response=" + response);
+        String expected = getResponse(context);
+        if (expected.equals(response)) {
+            Log.i("IAB response valid");
+
+            SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
+            prefs.edit()
+                    .putBoolean("pro", true)
+                    .putBoolean("play_store", false)
+                    .apply();
+
+            WidgetUnified.updateData(context);
+            return true;
+        } else {
+            Log.i("IAB response invalid");
+            return false;
+        }
+    }
+
+    static boolean isPro(Context context) {
+        if (BuildConfig.DEBUG && false)
+            return true;
+        return PreferenceManager.getDefaultSharedPreferences(context)
+                .getBoolean("pro", false);
+    }
+
+    private BroadcastReceiver receiver = new BroadcastReceiver() {
+        @Override
+        public void onReceive(Context context, Intent intent) {
+            if (getLifecycle().getCurrentState().isAtLeast(Lifecycle.State.STARTED)) {
+                if (ACTION_PURCHASE.equals(intent.getAction()))
+                    onPurchase(intent);
+                else if (ACTION_PURCHASE_CONSUME.equals(intent.getAction()))
+                    onPurchaseConsume(intent);
+                else if (ACTION_PURCHASE_ERROR.equals(intent.getAction()))
+                    onPurchaseError(intent);
+            }
+        }
+    };
+
+    private void onPurchase(Intent intent) {
+        if (Helper.isAmazonInstall() || isTesting(this)) {
+            String skuPro = getSkuPro();
+            Log.i("IAB purchase SKU=" + skuPro);
+            RequestId requestId = PurchasingService.purchase(skuPro);
+            Log.i("IAB request=" + requestId);
+        } else
+            try {
+                Uri uri = Uri.parse(BuildConfig.PRO_FEATURES_URI +
+                        "?challenge=" + getChallenge(this) +
+                        "&version=" + BuildConfig.VERSION_CODE);
+                Helper.view(this, uri, true);
+            } catch (NoSuchAlgorithmException ex) {
+                Log.unexpectedError(getSupportFragmentManager(), ex);
+            }
+    }
+
+    private void onPurchaseConsume(Intent intent) {
+        PurchasingService.getPurchaseUpdates(true);
+    }
+
+    private void onPurchaseError(Intent intent) {
+        String message = intent.getStringExtra("message");
+        Uri uri = Uri.parse(Helper.SUPPORT_URI);
+        if (!TextUtils.isEmpty(message))
+            uri = uri.buildUpon().appendQueryParameter("message", "IAB: " + message).build();
+        Helper.view(this, uri, true);
+    }
+
+    private void update() {
+        if (Helper.isAmazonInstall() || isTesting(this)) {
+            Log.i("IAB update");
+            PurchasingService.getUserData();
+            PurchasingService.getPurchaseUpdates(true); // TODO: reset?
+            Set<String> skus = new HashSet<>();
+            skus.add(getSkuPro());
+            PurchasingService.getProductData(skus);
+        }
+    }
+
+    @Override
+    public void onUserDataResponse(UserDataResponse response) {
+        Log.i("IAB user data status=" + response.getRequestStatus());
+
+        switch (response.getRequestStatus()) {
+            case SUCCESSFUL:
+                Log.i("IAB user=" + response.getUserData().toString().replace('\n', '|'));
+                currentUserId = response.getUserData().getUserId();
+                currentMarketplace = response.getUserData().getMarketplace();
+                for (IBillingListener listener : listeners)
+                    listener.onConnected();
+                break;
+
+            case FAILED:
+            case NOT_SUPPORTED:
+                break;
+        }
+    }
+
+    @Override
+    public void onPurchaseUpdatesResponse(PurchaseUpdatesResponse response) {
+        Log.i("IAB purchase updates status=" + response.getRequestStatus());
+
+        switch (response.getRequestStatus()) {
+            case SUCCESSFUL:
+                for (Receipt receipt : response.getReceipts())
+                    handle(receipt);
+
+                if (response.hasMore())
+                    PurchasingService.getPurchaseUpdates(false);
+                break;
+
+            case FAILED:
+                break;
+        }
+    }
+
+    @Override
+    public void onProductDataResponse(ProductDataResponse response) {
+        Log.i("IAB product data status=" + response.getRequestStatus());
+
+        switch (response.getRequestStatus()) {
+            case SUCCESSFUL:
+                for (final String sku : response.getUnavailableSkus())
+                    Log.i("IAB unavailable sku=" + sku);
+
+                Map<String, Product> products = response.getProductData();
+                for (final String key : products.keySet()) {
+                    Product product = products.get(key);
+                    Log.i("IAB product=" + product.toString().replace('\n', '|'));
+                    if (getSkuPro().equals(product.getSku()))
+                        for (IBillingListener listener : listeners)
+                            listener.onSkuDetails(product.getSku(), product.getPrice());
+                }
+                break;
+
+            case FAILED:
+                break;
+        }
+    }
+
+    @Override
+    public void onPurchaseResponse(PurchaseResponse response) {
+        Log.i("IAB purchase response status=" + response.getRequestStatus());
+
+        switch (response.getRequestStatus()) {
+            case SUCCESSFUL:
+                handle(response.getReceipt());
+                break;
+
+            case FAILED:
+                break;
+        }
+    }
+
+    private void handle(Receipt receipt) {
+        Log.i("IAB receipt=" + receipt.toString().replace('\n', '|') +
+                " canceled=" + receipt.isCanceled() + "/" + receipt.getCancelDate());
+
+        if (getSkuPro().equals(receipt.getSku())) {
+            SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
+            if (receipt.isCanceled()) {
+                prefs.edit().remove("pro").apply();
+                PurchasingService.notifyFulfillment(receipt.getReceiptId(), FulfillmentResult.UNAVAILABLE);
+            } else {
+                prefs.edit().putBoolean("pro", true).apply();
+                PurchasingService.notifyFulfillment(receipt.getReceiptId(), FulfillmentResult.FULFILLED);
+            }
+
+            WidgetUnified.updateData(this);
+
+            for (IBillingListener listener : listeners)
+                listener.onPurchased(receipt.getSku(), !receipt.isCanceled());
+        }
+    }
+
+    interface IBillingListener {
+        void onConnected();
+
+        void onDisconnected();
+
+        void onSkuDetails(String sku, String price);
+
+        void onPurchasePending(String sku);
+
+        void onPurchased(String sku, boolean purchased);
+
+        void onError(String message);
+    }
+
+    void addBillingListener(final IBillingListener listener, LifecycleOwner owner) {
+        Log.i("IAB adding billing listener=" + listener);
+        listeners.add(listener);
+
+        update();
+
+        owner.getLifecycle().addObserver(new LifecycleObserver() {
+            @OnLifecycleEvent(Lifecycle.Event.ON_DESTROY)
+            public void onDestroyed() {
+                Log.i("IAB removing billing listener=" + listener);
+                listeners.remove(listener);
+            }
+        });
+    }
+}

app/src/main/java/eu/faircode/email/Helper.java

@@ -471,6 +471,10 @@ public class Helper {
         return BuildConfig.PLAY_STORE_RELEASE;
     }
 
+    static boolean isAmazonInstall() {
+        return BuildConfig.AMAZON_RELEASE;
+    }
+
     static boolean hasPlayStore(Context context) {
         if (hasPlayStore == null)
             try {