feat: build windows dll and call dll in flutter

ui/lib/ffi/backend.dart

@@ -0,0 +1,41 @@
+import 'dart:ffi';
+import 'dart:io';
+import 'dart:isolate';
+
+import 'package:ui/widgets/utils.dart' as Utils;
+
+
+class FFIBackend {
+  final lib = DynamicLibrary.open(libname());
+
+  static String libname() {
+    if (Utils.isDesktop()) {
+      if (Platform.isWindows) {
+        return 'libpolaris.dll';
+      } else if (Platform.isLinux) {
+        return 'libpolaris.so';
+      } else if (Platform.isMacOS) {
+        return 'libpolaris.dylib';
+      } else {
+        throw UnsupportedError(
+            'Unsupported platform: ${Platform.operatingSystem}');
+      }
+    } else {
+      return "";
+    }
+  }
+
+  Future<void> start() async {
+    var s = lib
+        .lookup<NativeFunction<Void Function()>>('Start')
+        .asFunction<void Function()>();
+        
+    return Isolate.run(s);
+  }
+  Future<void> stop() async {
+    var s = lib
+        .lookup<NativeFunction<Void Function()>>('Stop')
+        .asFunction<void Function()>();
+    return s();
+  }
+}

ui/lib/main.dart

@@ -4,6 +4,7 @@ import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:go_router/go_router.dart';
 import 'package:intl/date_symbol_data_local.dart';
 import 'package:ui/activity.dart';
+import 'package:ui/ffi/backend.dart';
 import 'package:ui/init_wizard.dart';
 import 'package:ui/login_page.dart';
 import 'package:ui/movie_watchlist.dart';
@@ -15,7 +16,11 @@ import 'package:ui/tv_details.dart';
 import 'package:ui/welcome_page.dart';
 import 'package:ui/widgets/utils.dart';
 
-void main() {
+void main() async {
+  if (isDesktop()) {
+    FFIBackend().start();
+  }
+
   initializeDateFormatting()
       .then((_) => runApp(const ProviderScope(child: MyApp())));
 }

ui/lib/providers/APIs.dart

@@ -5,6 +5,7 @@ import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:go_router/go_router.dart';
 import 'package:ui/providers/server_response.dart';
+import 'package:ui/widgets/utils.dart';
 
 class APIs {
   static final _baseUrl = baseUrl();
@@ -68,6 +69,9 @@ class APIs {
 
   static String baseUrl() {
     if (kReleaseMode) {
+      if (isDesktop()) {
+        return "http://127.0.0.1:8080";
+      }
       return "";
     }
     return "http://127.0.0.1:8080";