add api_client

including GraphQL query and mutation functionality

including SSE streaming

lib/main.dart

@@ -1,4 +1,7 @@
+import 'dart:convert';
 import 'package:flutter/material.dart';
+import 'package:graphql/client.dart';
+import 'package:shopping_assistant_mobile_client/network/api_client.dart';
 
 void main() {
   runApp(const MyApp());
@@ -57,7 +60,8 @@ class MyHomePage extends StatefulWidget {
 class _MyHomePageState extends State<MyHomePage> {
   int _counter = 0;
 
-  void _incrementCounter() {
+  var client = ApiClient();
+  Future<void> _incrementCounter() async {
     setState(() {
       // This call to setState tells the Flutter framework that something has
       // changed in this State, which causes it to rerun the build method below
@@ -66,6 +70,35 @@ class _MyHomePageState extends State<MyHomePage> {
       // called again, and so nothing would appear to happen.
       _counter++;
     });
+
+    const String startPersonalWishlistMutations = r'''
+      mutation startPersonalWishlist($dto: WishlistCreateDtoInput!) {
+      startPersonalWishlist(dto: $dto) {
+        createdById, id, name, type
+      }
+    }
+    ''';
+
+    MutationOptions mutationOptions = MutationOptions(
+      document: gql(startPersonalWishlistMutations),
+      variables: const <String, dynamic>{
+        'dto': {
+          'firstMessageText': 'Gaming mechanical keyboard',
+          'type': 'Product'
+        },
+      }
+    );
+
+    var result = await client.mutate(mutationOptions);
+    print(jsonEncode(result));
+
+    var wishlistId = result?['startPersonalWishlist']['id'];
+    var sseStream = client.getServerSentEventStream(
+        'api/productssearch/search/$wishlistId',
+        {'text': 'silent wireless mouse'});
+    await for (var chunk in sseStream) {
+      print('${chunk.event}: ${chunk.data}');
+    }
   }
 
   @override

lib/models/enums/search_event_type.dart

@@ -0,0 +1,6 @@
+enum SearchEventType {
+  wishlist,
+  message,
+  suggestion,
+  product
+}

lib/models/server_sent_event.dart

@@ -0,0 +1,9 @@
+import 'package:shopping_assistant_mobile_client/models/enums/search_event_type.dart';
+
+class ServerSentEvent {
+
+  SearchEventType event;
+  String data;
+
+  ServerSentEvent(this.event, this.data);
+}

lib/network/api_client.dart

@@ -0,0 +1,98 @@
+import 'dart:async';
+import 'dart:convert';
+import 'dart:io';
+import 'package:graphql/client.dart';
+import 'package:http/http.dart' as http;
+import 'package:shopping_assistant_mobile_client/models/enums/search_event_type.dart';
+import 'package:shopping_assistant_mobile_client/models/global_instances/global_user.dart';
+import 'package:shopping_assistant_mobile_client/models/server_sent_event.dart';
+import 'package:shopping_assistant_mobile_client/network/authentication_service.dart';
+
+class ApiClient {
+  final String _apiBaseUrl = 'https://shopping-assistant-api-dev.azurewebsites.net/';
+  late String _accessToken;
+
+  final AuthenticationService _authenticationService = AuthenticationService();
+
+  late GraphQLClient _graphqlClient;
+  final http.Client _httpClient = http.Client();
+
+  Future<Map<String, dynamic>?> query(QueryOptions options) async {
+    await _setAuthentication();
+
+    final QueryResult result = await _graphqlClient.query(options);
+
+    if (result.hasException) {
+      print(result.exception.toString());
+    }
+
+    return result.data;
+  }
+
+  Future<Map<String, dynamic>?> mutate(MutationOptions options) async {
+    await _setAuthentication();
+
+    final QueryResult result = await _graphqlClient.mutate(options);
+
+    if (result.hasException) {
+      print(result.exception.toString());
+    }
+
+    return result.data;
+  }
+
+  Stream<ServerSentEvent> getServerSentEventStream(String urlPath, Map<dynamic, dynamic> requestBody) async* {
+    await _setAuthentication();
+
+    final url = Uri.parse('$_apiBaseUrl$urlPath');
+    final request = http.Request('POST', url);
+    request.body = jsonEncode(requestBody);
+    request.headers.addAll({
+      HttpHeaders.authorizationHeader: 'Bearer $_accessToken',
+      HttpHeaders.contentTypeHeader: 'application/json'
+    });
+    final response = await _httpClient.send(request);
+    
+    var eventType = SearchEventType.message;
+    await for (var line in response.stream.transform(utf8.decoder).transform(const LineSplitter())) {
+      if (line.startsWith('event: ')) {
+        var type = line.substring('event: '.length);
+        switch (type) {
+          case 'Message':
+            eventType = SearchEventType.message;
+            break;
+          case 'Suggestion':
+            eventType = SearchEventType.suggestion;
+            break;
+          case 'Product':
+            eventType = SearchEventType.product;
+            break;
+          case 'Wishlist':
+            eventType = SearchEventType.wishlist;
+            break;
+        }
+      }
+      if (line.startsWith('data: ')) {
+        yield ServerSentEvent(eventType, line.substring('data: '.length));
+      }
+    }
+  }
+
+  Future _setAuthentication() async {
+    _accessToken = await _authenticationService.getAccessToken();
+
+    GlobalUser.id = _authenticationService.getIdFromAccessToken(_accessToken);
+    GlobalUser.email = _authenticationService.getEmailFromAccessToken(_accessToken);
+    GlobalUser.phone = _authenticationService.getPhoneFromAccessToken(_accessToken);
+    // GlobalUser.roles = _authenticationService.getRolesFromAccessToken(_accessToken);
+
+    final httpLink = HttpLink('${_apiBaseUrl}graphql/', defaultHeaders: {
+      HttpHeaders.authorizationHeader: 'Bearer $_accessToken'
+    });
+
+    _graphqlClient = GraphQLClient(
+      cache: GraphQLCache(),
+      link: httpLink
+    );
+  }
+}