add: Preliminary support for flutter front-end calling rust back-end http request

flutter/lib/models/user_model.dart

@@ -9,6 +9,7 @@ import 'package:get/get.dart';
 import 'package:http/http.dart' as http;
 
 import '../common.dart';
+import '../utils/http_service.dart';
 import 'model.dart';
 import 'platform_model.dart';
 
@@ -135,8 +136,8 @@ class UserModel {
   /// throw [RequestException]
   Future<LoginResponse> login(LoginRequest loginRequest) async {
     final url = await bind.mainGetApiServer();
-    final resp = await http.post(Uri.parse('$url/api/login'),
-        headers: {'Content-Type': 'application/json'},
+    final resp = await HttpService().sendRequest(
+        '$url/api/login', HttpMethod.post,
         body: jsonEncode(loginRequest.toJson()));
 
     final Map<String, dynamic> body;

flutter/lib/utils/http_service.dart

@@ -0,0 +1,48 @@
+import 'dart:convert';
+import 'package:http/http.dart' as http;
+
+import '../models/platform_model.dart';
+
+enum HttpMethod { get, post, put, delete }
+
+class HttpService {
+  Future<http.Response> sendRequest(
+      String url,
+      HttpMethod method, {
+        Map<String, String>? headers,
+        dynamic body,
+      }) async {
+    headers ??= {'Content-Type': 'application/json'};
+    String headersJson = jsonEncode(headers);
+    String methodName = method.toString().split('.').last;
+
+    await bind.mainHttpRequest(url: url, method: methodName.toLowerCase(), body: body, header: headersJson);
+
+    var resJson = await _pollForResponse();
+    return _parseHttpResponse(resJson);
+  }
+
+  Future<String> _pollForResponse() async {
+    String responseJson = await bind.mainGetAsyncStatus();
+    while (responseJson == " ") {
+      await Future.delayed(const Duration(milliseconds: 100));
+      responseJson = await bind.mainGetAsyncStatus();
+    }
+    return responseJson;
+  }
+
+  http.Response _parseHttpResponse(String responseJson) {
+    try {
+      var parsedJson = jsonDecode(responseJson);
+      String body = parsedJson['body'];
+      Map<String, String> headers = {};
+      for (var key in parsedJson['headers'].keys) {
+        headers[key] = parsedJson['headers'][key];
+      }
+      int statusCode = parsedJson['status_code'];
+      return http.Response(body, statusCode, headers: headers);
+    } catch (e) {
+      throw Exception('Failed to parse response: $e');
+    }
+  }
+}