Implement background notifications, I think

android/app/src/main/AndroidManifest.xml

@@ -1,6 +1,7 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="xyz.janderedev.feet">
     <uses-permission android:name="android.permission.INTERNET" />
+    <uses-permission android:name="android.permission.POST_NOTIFICATIONS"/>
     <queries>
       <intent>
         <action android:name="android.intent.action.VIEW" />
@@ -41,5 +42,12 @@
         <meta-data
             android:name="flutterEmbedding"
             android:value="2" />
+
+        <receiver android:name="com.dexterous.flutterlocalnotifications.ScheduledNotificationBootReceiver">
+          <intent-filter>
+              <action android:name="android.intent.action.BOOT_COMPLETED"></action>
+          </intent-filter>
+        </receiver>
+        <receiver android:name="com.dexterous.flutterlocalnotifications.ScheduledNotificationReceiver" />
     </application>
 </manifest>

lib/api/api.dart

@@ -4,6 +4,7 @@ import 'dart:convert';
 
 import 'package:http/http.dart' as http;
 import 'package:crypto/crypto.dart';
+import 'package:shared_preferences/shared_preferences.dart';
 
 part 'feed.dart';
 part 'item.dart';
@@ -21,12 +22,16 @@ class FeverAPI {
   String? apiKey;
   String? apiUrl;
 
+  late final APICache cache;
+
   /// We use a shared HTTP client for all requests
   final _httpClient = http.Client();
 
-  late final APICache cache;
+  /// If set, the `newestKnownPost` value will be updated automatically.
+  /// This is used for notifications.
+  SharedPreferences? sharedPrefs;
 
-  FeverAPI({this.apiKey, this.apiUrl}) {
+  FeverAPI({this.apiKey, this.apiUrl, this.sharedPrefs}) {
     cache = APICache(this);
   }
 
@@ -64,19 +69,20 @@ class FeverAPI {
   }
 
   APIRequestBuilder request() {
-    return APIRequestBuilder(this, _httpClient);
+    return APIRequestBuilder(this, _httpClient, sharedPrefs);
   }
 }
 
 class APIRequestBuilder {
   final FeverAPI api;
+  final SharedPreferences? _sharedPrefs;
   final http.Client _httpClient;
 
   List<String> args = [];
   Item? _markedItem;
   ItemMarkType? _markedItemAs;
 
-  APIRequestBuilder(this.api, this._httpClient);
+  APIRequestBuilder(this.api, this._httpClient, this._sharedPrefs);
 
   void _addArg(String arg) {
     if (!args.contains(arg)) args.add(arg);
@@ -173,12 +179,19 @@ class APIRequestBuilder {
     }
 
     if (data.containsKey('items')) {
+      var currentHighest = _sharedPrefs?.getInt('newestKnownPost') ?? 0;
+
       List<Item> items = (data['items'] as List<dynamic>)
           .map((json) => Item.fromJSON(api, json))
           .toList();
 
       for (var item in items) {
+        if (item.id > currentHighest) {
+          currentHighest = item.id;
+        }
+
         api.cache.items.set(item.id, item);
+        _sharedPrefs?.setInt('newestKnownPost', currentHighest);
       }
     }
 

lib/main.dart

@@ -1,5 +1,6 @@
 import 'dart:async';
 
+import 'package:feet/notifications/tasks.dart';
 import 'package:feet/widgets/centered_page_hint.dart';
 import 'package:feet/widgets/filter_menu.dart';
 import 'package:feet/widgets/homepage_post.dart';
@@ -15,6 +16,7 @@ import 'api/api.dart';
 const FETCH_MAX_POSTS = 1000;
 
 void main() {
+  setupBackgroundTasks();
   runApp(MyApp());
 }
 
@@ -27,6 +29,7 @@ class MyApp extends StatelessWidget {
   Future<bool> _loadPrefs() async {
     var prefs = await SharedPreferences.getInstance();
     this.prefs = prefs;
+    api.sharedPrefs = prefs;
     var apiKey = prefs.getString('apiKey'), apiUrl = prefs.getString('apiUrl');
 
     if (apiUrl != null && apiKey != null) {

lib/notifications/tasks.dart

@@ -0,0 +1,116 @@
+import 'dart:convert';
+import 'dart:math';
+
+import 'package:feet/api/api.dart';
+import 'package:flutter/foundation.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_local_notifications/flutter_local_notifications.dart';
+import 'package:permission_handler/permission_handler.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+import 'package:workmanager/workmanager.dart';
+
+@pragma('vm:entry-point')
+void callbackDispatcher() {
+  Workmanager().executeTask((taskName, inputData) async {
+    print("Native called background task: $taskName");
+
+    if (taskName == 'fetchNotifications') {
+      final sharedPreferences = await SharedPreferences.getInstance();
+
+      try {
+        var initialized = await FlutterLocalNotificationsPlugin().initialize(
+          const InitializationSettings(
+            android: AndroidInitializationSettings('@mipmap/ic_launcher'),
+          ),
+        );
+
+        if (initialized == false) {
+          print("Notification plugin did not initialize; cancelling task");
+          return true;
+        }
+
+        var apiUrl = sharedPreferences.getString('apiUrl'),
+            apiKey = sharedPreferences.getString('apiKey'),
+            latest = sharedPreferences.getInt('newestKnownPost');
+
+        if (apiUrl == null || apiKey == null) {
+          print("API URL or API key not set; cancelling task");
+          return true;
+        }
+
+        var api = FeverAPI(
+          apiKey: apiKey,
+          apiUrl: apiUrl,
+          sharedPrefs: sharedPreferences,
+        );
+
+        await api.request().withItems().sinceId(latest ?? 0).execute();
+        var items =
+            api.cache.items.getAll().values.where((post) => !post.isRead);
+
+        // Only fetch feeds and favicons if necessary to avoid wasting bandwidth
+        if (items.isNotEmpty) {
+          print("New posts found, fetching feeds and favicons");
+          await api.request().withFeeds().withFavicons().execute();
+        }
+
+        for (var item in items) {
+          var feed = api.cache.feeds.get(item.feedId);
+          print("Notifying for post: ${item.id}");
+
+          AndroidBitmap<Object>? iconData;
+          var favicon = api.cache.favicons.get(feed?.faviconId ?? -1);
+          if (favicon != null) {
+            try {
+              iconData = ByteArrayAndroidBitmap.fromBase64String(
+                  favicon.data.split(',')[1]);
+            } catch (e) {
+              print("Failed to decode favicon: $e - Continuing");
+            }
+          }
+
+          await FlutterLocalNotificationsPlugin().show(
+            Random().nextInt(10000000), // Can't use the post ID here because
+            // FreshRSS's IDs are too large
+            feed != null ? 'New post - ${feed.title}' : 'New post',
+            item.title,
+            NotificationDetails(
+              android: AndroidNotificationDetails(
+                'new_posts',
+                'New posts',
+                autoCancel: true,
+                channelShowBadge: true,
+                importance: Importance.low,
+                largeIcon: iconData,
+              ),
+            ),
+          );
+        }
+      } catch (e) {
+        print(e);
+        return false;
+      }
+
+      return true;
+    }
+
+    return true;
+  });
+}
+
+void setupBackgroundTasks() async {
+  WidgetsFlutterBinding.ensureInitialized();
+  Workmanager().initialize(
+    callbackDispatcher,
+    isInDebugMode: kDebugMode,
+  );
+
+  await Permission.notification.request();
+
+  // Runs every 15 minutes
+  Workmanager().registerPeriodicTask(
+    'fetch-notifications',
+    'fetchNotifications',
+    initialDelay: const Duration(seconds: 30),
+  );
+}

macos/Flutter/GeneratedPluginRegistrant.swift

@@ -6,6 +6,7 @@ import FlutterMacOS
 import Foundation
 
 import dynamic_color
+import flutter_local_notifications
 import path_provider_macos
 import share_plus
 import shared_preferences_macos
@@ -14,6 +15,7 @@ import wakelock_macos
 
 func RegisterGeneratedPlugins(registry: FlutterPluginRegistry) {
   DynamicColorPlugin.register(with: registry.registrar(forPlugin: "DynamicColorPlugin"))
+  FlutterLocalNotificationsPlugin.register(with: registry.registrar(forPlugin: "FlutterLocalNotificationsPlugin"))
   PathProviderPlugin.register(with: registry.registrar(forPlugin: "PathProviderPlugin"))
   SharePlusMacosPlugin.register(with: registry.registrar(forPlugin: "SharePlusMacosPlugin"))
   SharedPreferencesPlugin.register(with: registry.registrar(forPlugin: "SharedPreferencesPlugin"))

pubspec.lock

@@ -1,6 +1,14 @@
 # Generated by pub
 # See https://dart.dev/tools/pub/glossary#lockfile
 packages:
+  args:
+    dependency: transitive
+    description:
+      name: args
+      sha256: "139d809800a412ebb26a3892da228b2d0ba36f0ef5d9a82166e5e52ec8d61611"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.3.2"
   async:
     dependency: transitive
     description:
@@ -89,6 +97,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "1.0.5"
+  dbus:
+    dependency: transitive
+    description:
+      name: dbus
+      sha256: "3350efa144252eaa4264055dded4404a94b770cfe914f1d08c20953aee55cac2"
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.5.4"
   dynamic_color:
     dependency: "direct main"
     description:
@@ -150,6 +166,30 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "2.0.1"
+  flutter_local_notifications:
+    dependency: "direct main"
+    description:
+      name: flutter_local_notifications
+      sha256: "11d12ac8c713d28a654036c6e61464ef039eb560296282b17b933682ede0b4b8"
+      url: "https://pub.dev"
+    source: hosted
+    version: "9.1.4"
+  flutter_local_notifications_linux:
+    dependency: transitive
+    description:
+      name: flutter_local_notifications_linux
+      sha256: "0824c36855ef1f159e1b957e4ff43dfd171372d6915424bc5004e277db4f1bc5"
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.3.0"
+  flutter_local_notifications_platform_interface:
+    dependency: transitive
+    description:
+      name: flutter_local_notifications_platform_interface
+      sha256: "21bceee103a66a53b30ea9daf677f990e5b9e89b62f222e60dd241cd08d63d3a"
+      url: "https://pub.dev"
+    source: hosted
+    version: "5.0.0"
   flutter_math_fork:
     dependency: transitive
     description:
@@ -344,6 +384,54 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "2.1.3"
+  pedantic:
+    dependency: transitive
+    description:
+      name: pedantic
+      sha256: "67fc27ed9639506c856c840ccce7594d0bdcd91bc8d53d6e52359449a1d50602"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.11.1"
+  permission_handler:
+    dependency: "direct main"
+    description:
+      name: permission_handler
+      sha256: "33c6a1253d1f95fd06fa74b65b7ba907ae9811f9d5c1d3150e51417d04b8d6a8"
+      url: "https://pub.dev"
+    source: hosted
+    version: "10.2.0"
+  permission_handler_android:
+    dependency: transitive
+    description:
+      name: permission_handler_android
+      sha256: "8028362b40c4a45298f1cbfccd227c8dd6caf0e27088a69f2ba2ab15464159e2"
+      url: "https://pub.dev"
+    source: hosted
+    version: "10.2.0"
+  permission_handler_apple:
+    dependency: transitive
+    description:
+      name: permission_handler_apple
+      sha256: "9c370ef6a18b1c4b2f7f35944d644a56aa23576f23abee654cf73968de93f163"
+      url: "https://pub.dev"
+    source: hosted
+    version: "9.0.7"
+  permission_handler_platform_interface:
+    dependency: transitive
+    description:
+      name: permission_handler_platform_interface
+      sha256: "68abbc472002b5e6dfce47fe9898c6b7d8328d58b5d2524f75e277c07a97eb84"
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.9.0"
+  permission_handler_windows:
+    dependency: transitive
+    description:
+      name: permission_handler_windows
+      sha256: f67cab14b4328574938ecea2db3475dad7af7ead6afab6338772c5f88963e38b
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.1.2"
   petitparser:
     dependency: transitive
     description:
@@ -525,6 +613,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "0.4.16"
+  timezone:
+    dependency: transitive
+    description:
+      name: timezone
+      sha256: "57b35f6e8ef731f18529695bffc62f92c6189fac2e52c12d478dec1931afb66e"
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.8.0"
   tuple:
     dependency: transitive
     description:
@@ -741,6 +837,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "3.1.3"
+  workmanager:
+    dependency: "direct main"
+    description:
+      name: workmanager
+      sha256: e0be7e35d644643f164ee45d2ce14414f0e0fdde19456aa66065f35a0b1d2ea1
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.5.1"
   xdg_directories:
     dependency: transitive
     description:

pubspec.yaml

@@ -42,6 +42,9 @@ dependencies:
   share_plus: ^6.3.0
   flutter_html: ^2.2.1
   url_launcher: ^6.1.7
+  workmanager: ^0.5.1
+  flutter_local_notifications: ^9.1.4
+  permission_handler: ^10.2.0
 
 dev_dependencies:
   flutter_test:

windows/flutter/generated_plugin_registrant.cc

@@ -7,12 +7,15 @@
 #include "generated_plugin_registrant.h"
 
 #include <dynamic_color/dynamic_color_plugin_c_api.h>
+#include <permission_handler_windows/permission_handler_windows_plugin.h>
 #include <share_plus/share_plus_windows_plugin_c_api.h>
 #include <url_launcher_windows/url_launcher_windows.h>
 
 void RegisterPlugins(flutter::PluginRegistry* registry) {
   DynamicColorPluginCApiRegisterWithRegistrar(
       registry->GetRegistrarForPlugin("DynamicColorPluginCApi"));
+  PermissionHandlerWindowsPluginRegisterWithRegistrar(
+      registry->GetRegistrarForPlugin("PermissionHandlerWindowsPlugin"));
   SharePlusWindowsPluginCApiRegisterWithRegistrar(
       registry->GetRegistrarForPlugin("SharePlusWindowsPluginCApi"));
   UrlLauncherWindowsRegisterWithRegistrar(

windows/flutter/generated_plugins.cmake

@@ -4,6 +4,7 @@
 
 list(APPEND FLUTTER_PLUGIN_LIST
   dynamic_color
+  permission_handler_windows
   share_plus
   url_launcher_windows
 )