Implement basic IAP support for Android

It's very ugly, but it works.

android/build.gradle

@@ -10,7 +10,7 @@ buildscript {
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.2.1'
+        classpath 'com.android.tools.build:gradle:3.3.2'
         classpath 'com.google.gms:google-services:3.2.1'
         classpath 'io.fabric.tools:gradle:1.+'
     }

lib/features.dart

@@ -1,4 +1,4 @@
 class Features {
   static bool perFolderConfig = false;
-  static bool purchaseProModeAvailable = false;
+  static bool purchaseProModeAvailable = true;
 }

lib/screens/home_screen.dart

@@ -1,5 +1,6 @@
 import 'package:flutter/material.dart';
 import 'package:gitjournal/core/flattened_notes_folder.dart';
+import 'package:gitjournal/iap.dart';
 import 'package:provider/provider.dart';
 
 import 'package:gitjournal/core/notes_folder_fs.dart';
@@ -17,6 +18,9 @@ class _HomeScreenState extends State<HomeScreen> {
   @override
   void initState() {
     super.initState();
+
+    InAppPurchases.confirmProPurchase();
+
     Future.delayed(Duration.zero, () {
       if (!mounted) return;
       final rootFolder = Provider.of<NotesFolderFS>(context);

lib/screens/purchase_screen.dart

@@ -2,9 +2,11 @@ import 'dart:async';
 
 import 'package:flutter/material.dart';
 import 'package:gitjournal/analytics.dart';
+import 'package:gitjournal/.env.dart';
 
 import 'package:flutter/services.dart';
-import 'package:flutter_inapp_purchase/flutter_inapp_purchase.dart';
+import 'package:gitjournal/settings.dart';
+import 'package:purchases_flutter/purchases_flutter.dart';
 
 class PurchaseScreen extends StatefulWidget {
   @override
@@ -12,13 +14,7 @@ class PurchaseScreen extends StatefulWidget {
 }
 
 class _PurchaseScreenState extends State<PurchaseScreen> {
-  String _platformVersion = 'Unknown';
-  var _skus = ['sku_monthly_min'];
-  List<IAPItem> _iapItems = [];
-
-  StreamSubscription _purchaseUpdatedSubscription;
-  StreamSubscription _purchaseErrorSubscription;
-  StreamSubscription _conectionSubscription;
+  Offerings _offerings;
 
   @override
   void initState() {
@@ -27,36 +23,18 @@ class _PurchaseScreenState extends State<PurchaseScreen> {
   }
 
   Future<void> initPlatformState() async {
-    // prepare
-    var result = await FlutterInappPurchase.instance.initConnection;
-    print('result: $result');
+    Purchases.setDebugLogsEnabled(true);
+    await Purchases.setup(environment['revenueCat']);
+
+    Offerings offerings = await Purchases.getOfferings();
 
     // If the widget was removed from the tree while the asynchronous platform
     // message was in flight, we want to discard the reply rather than calling
     // setState to update our non-existent appearance.
     if (!mounted) return;
 
-    try {
-      _iapItems = await FlutterInappPurchase.instance.getSubscriptions(_skus);
-      setState(() {});
-      print("IAP ITEMS $_iapItems");
-    } catch (err) {
-      print('getSubscriptions error: $err');
-    }
-
-    _conectionSubscription =
-        FlutterInappPurchase.connectionUpdated.listen((connected) {
-      print('connected: $connected');
-    });
-
-    _purchaseUpdatedSubscription =
-        FlutterInappPurchase.purchaseUpdated.listen((productItem) {
-      print('purchase-updated: $productItem');
-    });
-
-    _purchaseErrorSubscription =
-        FlutterInappPurchase.purchaseError.listen((purchaseError) {
-      print('purchase-error: $purchaseError');
+    setState(() {
+      _offerings = offerings;
     });
   }
 
@@ -65,10 +43,11 @@ class _PurchaseScreenState extends State<PurchaseScreen> {
     var theme = Theme.of(context);
     var textTheme = theme.textTheme;
 
-    if (_iapItems.isEmpty) {
+    if (_offerings == null) {
       return const PurchaseLoadingScreen();
     }
-    var iap = _iapItems[0];
+    var offering = _offerings.current;
+    var monthly = offering.monthly;
 
     // FIXME: This screen needs to be made way way more beautiful
     //        It's an extrememly important screen
@@ -77,12 +56,7 @@ class _PurchaseScreenState extends State<PurchaseScreen> {
       children: <Widget>[
         Text('Pro Version', style: textTheme.display2),
         Text('Support GitJournal by going Pro', style: textTheme.subhead),
-        RaisedButton(
-          child: Text('Subscribe for ${iap.localizedPrice} / month'),
-          onPressed: () {
-            FlutterInappPurchase.instance.requestSubscription(_skus[0]);
-          },
-        ),
+        PurchaseButton(monthly),
       ],
       mainAxisAlignment: MainAxisAlignment.spaceAround,
     );
@@ -104,6 +78,62 @@ class _PurchaseScreenState extends State<PurchaseScreen> {
   }
 }
 
+class PurchaseButton extends StatelessWidget {
+  final Package package;
+
+  PurchaseButton(this.package);
+
+  @override
+  Widget build(BuildContext context) {
+    return RaisedButton(
+      child: Text('Subscribe for ${package.product.priceString} / month'),
+      onPressed: () async {
+        try {
+          var purchaserInfo = await Purchases.purchasePackage(package);
+          var isPro = purchaserInfo.entitlements.all["pro"].isActive;
+          if (isPro) {
+            Settings.instance.proMode = true;
+            Settings.instance.save();
+
+            // vHanda FIXME: Show some screen to indicate bought purchase?
+            Navigator.of(context).pop();
+            return;
+          }
+        } on PlatformException catch (e) {
+          var errorCode = PurchasesErrorHelper.getErrorCode(e);
+          var errorContent = "";
+          switch (errorCode) {
+            case PurchasesErrorCode.purchaseCancelledError:
+              errorContent = "User cancelled";
+              break;
+
+            case PurchasesErrorCode.purchaseNotAllowedError:
+              errorContent = "User not allowed to purchase";
+              break;
+
+            default:
+              errorContent = errorCode.toString();
+              break;
+          }
+
+          var dialog = AlertDialog(
+            title: const Text("Purchase Failed"),
+            content: Text(errorContent),
+            actions: <Widget>[
+              FlatButton(
+                child: const Text("OK"),
+                onPressed: () => Navigator.of(context).pop(),
+              ),
+            ],
+          );
+          await showDialog(context: context, builder: (context) => dialog);
+        }
+        return null;
+      },
+    );
+  }
+}
+
 class PurchaseLoadingScreen extends StatelessWidget {
   const PurchaseLoadingScreen({Key key}) : super(key: key);
 

lib/widgets/app_drawer.dart

@@ -80,7 +80,7 @@ class AppDrawer extends StatelessWidget {
                 );
               },
             ),
-          if (Features.purchaseProModeAvailable && !!Settings.instance.proMode)
+          if (Features.purchaseProModeAvailable && !Settings.instance.proMode)
             divider,
           _buildDrawerTile(
             context,

pubspec.lock

@@ -207,13 +207,6 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "2.2.1+1"
-  flutter_inapp_purchase:
-    dependency: "direct main"
-    description:
-      name: flutter_inapp_purchase
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "2.1.4"
   flutter_launcher_icons:
     dependency: "direct dev"
     description:
@@ -537,6 +530,13 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "1.4.2"
+  purchases_flutter:
+    dependency: "direct main"
+    description:
+      name: purchases_flutter
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.1.0"
   quiver:
     dependency: transitive
     description:

pubspec.yaml

@@ -41,7 +41,7 @@ dependencies:
   font_awesome_flutter: ^8.7.0
   sentry: ">=3.0.0 <4.0.0"
   equatable: ^1.1.0
-  flutter_inapp_purchase: ^2.1.4
+  purchases_flutter: ^1.1.0
 
 dev_dependencies:
   flutter_launcher_icons: "^0.7.2"