Add update checker

app/lib/update_checker.dart

@@ -0,0 +1,53 @@
+import 'dart:convert';
+
+import 'package:http/http.dart' as http;
+import 'package:logging/logging.dart';
+import 'package:nc_photos/k.dart' as k;
+
+enum UpdateCheckerResult {
+  updateAvailable,
+  alreadyLatest,
+  error,
+}
+
+class UpdateChecker {
+  Future<UpdateCheckerResult> call() async {
+    try {
+      final uri = Uri.https("bit.ly", "3pb2oG9");
+      final req = http.Request("GET", uri);
+      final response =
+          await http.Response.fromStream(await http.Client().send(req));
+      if (response.statusCode != 200) {
+        _log.severe("[call] Failed GETing URL: ${response.statusCode}");
+        return UpdateCheckerResult.error;
+      }
+      final body = response.body;
+      final json = jsonDecode(body) as Map;
+      final data = json[_buildVariant] as Map;
+      _log.info("[call] Update data: ${jsonEncode(data)}");
+      final latest = data["v"];
+      _versionStr = data["vStr"];
+      _updateUrl = data["url"];
+      if (latest > k.version) {
+        return UpdateCheckerResult.updateAvailable;
+      } else {
+        return UpdateCheckerResult.alreadyLatest;
+      }
+    } catch (e, stackTrace) {
+      _log.severe("[call] Exception", e, stackTrace);
+      return UpdateCheckerResult.error;
+    }
+  }
+
+  /// Return the binary url (if available) after [call] returned with
+  /// [UpdateCheckerResult.updateAvailable]
+  String? get updateUrl => _updateUrl;
+  String? get versionStr => _versionStr;
+
+  String? _updateUrl;
+  String? _versionStr;
+
+  static const _buildVariant = "";
+
+  static final _log = Logger("update_checker.UpdateChecker");
+}

app/lib/widget/my_app.dart

@@ -56,6 +56,7 @@ import 'package:nc_photos/widget/splash.dart';
 import 'package:nc_photos/widget/trashbin_browser.dart';
 import 'package:nc_photos/widget/trashbin_viewer.dart';
 import 'package:nc_photos/widget/trusted_cert_manager.dart';
+import 'package:nc_photos/widget/update_checker.dart';
 import 'package:nc_photos/widget/viewer.dart';
 import 'package:np_codegen/np_codegen.dart';
 import 'package:np_db/np_db.dart';
@@ -242,6 +243,7 @@ class _WrappedAppState extends State<_WrappedApp>
     route ??= _handleCollectionBrowserRoute(settings);
     route ??= _handleAccountSettingsRoute(settings);
     route ??= _handlePlacePickerRoute(settings);
+    route ??= _handleUpdateCheckerRoute(settings);
     return route;
   }
 
@@ -563,6 +565,17 @@ class _WrappedAppState extends State<_WrappedApp>
     return null;
   }
 
+  Route<dynamic>? _handleUpdateCheckerRoute(RouteSettings settings) {
+    try {
+      if (settings.name == UpdateChecker.routeName) {
+        return UpdateChecker.buildRoute();
+      }
+    } catch (e) {
+      _log.severe("[_handleUpdateCheckerRoute] Failed while handling route", e);
+    }
+    return null;
+  }
+
   late final _bloc = context.read<_Bloc>();
   final _scaffoldMessengerKey = GlobalKey<ScaffoldMessengerState>();
   final _navigatorKey = GlobalKey<NavigatorState>();

app/lib/widget/settings.dart

@@ -27,6 +27,7 @@ import 'package:nc_photos/widget/settings/photos_settings.dart';
 import 'package:nc_photos/widget/settings/settings_list_caption.dart';
 import 'package:nc_photos/widget/settings/theme_settings.dart';
 import 'package:nc_photos/widget/settings/viewer_settings.dart';
+import 'package:nc_photos/widget/update_checker.dart';
 import 'package:np_codegen/np_codegen.dart';
 
 part 'settings.g.dart';
@@ -146,6 +147,12 @@ class _SettingsState extends State<Settings> {
                     launch(help_util.donateUrl);
                   },
                 ),
+                ListTile(
+                  title: const Text("Check for updates"),
+                  onTap: () {
+                    Navigator.of(context).pushNamed(UpdateChecker.routeName);
+                  },
+                ),
                 ListTile(
                   title: Text(L10n.global().settingsSourceCodeTitle),
                   onTap: () {

app/lib/widget/update_checker.dart

@@ -0,0 +1,209 @@
+import 'package:flutter/material.dart';
+import 'package:nc_photos/app_localizations.dart';
+import 'package:nc_photos/help_utils.dart' as help_util;
+import 'package:nc_photos/k.dart' as k;
+import 'package:nc_photos/update_checker.dart' as checker;
+import 'package:nc_photos/url_launcher_util.dart';
+
+class UpdateChecker extends StatefulWidget {
+  static const routeName = "/update-checker";
+
+  static Route buildRoute() => MaterialPageRoute(
+        builder: (context) => const UpdateChecker(),
+      );
+
+  const UpdateChecker({super.key});
+
+  @override
+  createState() => _UpdateCheckerState();
+}
+
+class _UpdateCheckerState extends State<UpdateChecker> {
+  @override
+  initState() {
+    super.initState();
+    _work();
+  }
+
+  @override
+  build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(
+        backgroundColor: Colors.transparent,
+        shadowColor: Colors.transparent,
+      ),
+      body: Builder(
+        builder: _buildContent,
+      ),
+    );
+  }
+
+  Widget _buildContent(BuildContext context) {
+    return Column(
+      children: [
+        Expanded(
+          child: SingleChildScrollView(
+            child: Padding(
+              padding: const EdgeInsets.symmetric(horizontal: 16),
+              child: Column(
+                crossAxisAlignment: CrossAxisAlignment.start,
+                children: [
+                  const SizedBox(height: 32),
+                  const Align(
+                    alignment: Alignment.center,
+                    child: Text(
+                      "Photos ${k.versionStr}",
+                      style: TextStyle(fontSize: 24),
+                    ),
+                  ),
+                  const SizedBox(height: 32),
+                  Align(
+                    alignment: Alignment.center,
+                    child: _getStatusWidget(),
+                  ),
+                  const SizedBox(height: 16),
+                  Align(
+                    alignment: Alignment.center,
+                    child: Text(
+                      _getStatusText(),
+                      textAlign: TextAlign.center,
+                      style: const TextStyle(fontSize: 18),
+                    ),
+                  ),
+                  const SizedBox(height: 16),
+                  if (_result == checker.UpdateCheckerResult.updateAvailable)
+                    Align(
+                      alignment: Alignment.center,
+                      child: ElevatedButton(
+                        onPressed: () {
+                          if (_updateUrl != null) {
+                            launch(_updateUrl!);
+                          } else {
+                            // fallback
+                            launch("https://bit.ly/3wNLHFo");
+                          }
+                        },
+                        child: const Text("GET UPDATE"),
+                      ),
+                    )
+                  else
+                    const SizedBox(height: 48),
+                  const SizedBox(height: 56),
+                  Center(
+                    child: Text(
+                      L10n.global().donationShortMessage,
+                      style: const TextStyle(
+                          fontSize: 18, fontWeight: FontWeight.bold),
+                    ),
+                  ),
+                  const SizedBox(height: 8),
+                  Align(
+                    alignment: Alignment.center,
+                    child: ElevatedButton(
+                      onPressed: () {
+                        launch(help_util.donateUrl);
+                      },
+                      child: Text(L10n.global().donationButtonLabel),
+                    ),
+                  ),
+                  const SizedBox(height: 16),
+                ],
+              ),
+            ),
+          ),
+        ),
+        Container(
+          padding: const EdgeInsets.symmetric(horizontal: 24),
+          child: Row(
+            mainAxisSize: MainAxisSize.max,
+            children: [
+              const Expanded(
+                child: Text("Having problems?"),
+              ),
+              TextButton(
+                onPressed: () {
+                  launch("https://bit.ly/3wNLHFo");
+                },
+                child: const Text("CHECK MANUALLY"),
+              ),
+            ],
+          ),
+        ),
+      ],
+    );
+  }
+
+  Future<void> _work() async {
+    await Future.delayed(const Duration(seconds: 1));
+    final uc = checker.UpdateChecker();
+    final result = await uc();
+    if (result == checker.UpdateCheckerResult.updateAvailable) {
+      _updateUrl = uc.updateUrl;
+      _versionStr = uc.versionStr;
+    }
+    if (mounted) {
+      setState(() {
+        _result = result;
+      });
+    }
+  }
+
+  Widget _getStatusWidget() {
+    if (_result == null) {
+      return const SizedBox(
+        width: _statusIconSize,
+        height: _statusIconSize,
+        child: Padding(
+          padding: EdgeInsets.all(8),
+          child: CircularProgressIndicator(),
+        ),
+      );
+    } else {
+      switch (_result!) {
+        case checker.UpdateCheckerResult.updateAvailable:
+          return Icon(
+            Icons.upload,
+            color: Colors.orange[700],
+            size: _statusIconSize,
+          );
+
+        case checker.UpdateCheckerResult.alreadyLatest:
+          return Icon(
+            Icons.done,
+            color: Colors.green[600],
+            size: _statusIconSize,
+          );
+
+        case checker.UpdateCheckerResult.error:
+          return Icon(
+            Icons.warning,
+            color: Colors.red[700],
+            size: _statusIconSize,
+          );
+      }
+    }
+  }
+
+  String _getStatusText() {
+    if (_result == null) {
+      return "Checking...";
+    } else {
+      switch (_result!) {
+        case checker.UpdateCheckerResult.updateAvailable:
+          return "Update available ($_versionStr)";
+
+        case checker.UpdateCheckerResult.alreadyLatest:
+          return "You are running the latest version";
+
+        case checker.UpdateCheckerResult.error:
+          return "Failed checking for updates";
+      }
+    }
+  }
+
+  checker.UpdateCheckerResult? _result;
+  String? _updateUrl;
+  String? _versionStr;
+
+  static const _statusIconSize = 72.0;
+}