Flutter Integration

# pubspec.yaml
dependencies:
  http: ^1.1.0
  shared_preferences: ^2.2.0
  provider: ^6.1.0

// lib/services/api_client.dart
import 'dart:convert';
import 'package:http/http.dart' as http;
import 'package:shared_preferences/shared_preferences.dart';
 
class ApiClient {
  static const String baseUrl = 'https://api.yourapp.com';
  String? _token;
 
  Future<void> init() async {
    final prefs = await SharedPreferences.getInstance();
    _token = prefs.getString('token');
  }
 
  Future<void> setToken(String token) async {
    _token = token;
    final prefs = await SharedPreferences.getInstance();
    await prefs.setString('token', token);
  }
 
  Future<void> clearToken() async {
    _token = null;
    final prefs = await SharedPreferences.getInstance();
    await prefs.remove('token');
  }
 
  Map<String, String> get _headers => {
    'Content-Type': 'application/json',
    if (_token != null) 'Authorization': 'Bearer $_token',
  };
 
  Future<dynamic> get(String path) async {
    final response = await http.get(
      Uri.parse('$baseUrl$path'),
      headers: _headers,
    );
    return _handleResponse(response);
  }
 
  Future<dynamic> post(String path, Map<String, dynamic> body) async {
    final response = await http.post(
      Uri.parse('$baseUrl$path'),
      headers: _headers,
      body: jsonEncode(body),
    );
    return _handleResponse(response);
  }
 
  Future<dynamic> patch(String path, Map<String, dynamic> body) async {
    final response = await http.patch(
      Uri.parse('$baseUrl$path'),
      headers: _headers,
      body: jsonEncode(body),
    );
    return _handleResponse(response);
  }
 
  Future<void> delete(String path) async {
    final response = await http.delete(
      Uri.parse('$baseUrl$path'),
      headers: _headers,
    );
    _handleResponse(response);
  }
 
  dynamic _handleResponse(http.Response response) {
    if (response.statusCode >= 200 && response.statusCode < 300) {
      if (response.body.isEmpty) return null;
      return jsonDecode(response.body);
    }
    throw ApiException(
      statusCode: response.statusCode,
      message: response.body,
    );
  }
}
 
class ApiException implements Exception {
  final int statusCode;
  final String message;
 
  ApiException({required this.statusCode, required this.message});
}

// lib/models/project.dart
class Project {
  final String id;
  final String name;
  final String? description;
  final String organizationId;
  final DateTime createdAt;
  final DateTime updatedAt;
  final List<Task>? tasks;
 
  Project({
    required this.id,
    required this.name,
    this.description,
    required this.organizationId,
    required this.createdAt,
    required this.updatedAt,
    this.tasks,
  });
 
  factory Project.fromJson(Map<String, dynamic> json) {
    return Project(
      id: json['id'],
      name: json['name'],
      description: json['description'],
      organizationId: json['organizationId'],
      createdAt: DateTime.parse(json['createdAt']),
      updatedAt: DateTime.parse(json['updatedAt']),
      tasks: json['tasks'] != null
          ? (json['tasks'] as List).map((t) => Task.fromJson(t)).toList()
          : null,
    );
  }
}

// lib/services/project_service.dart
import 'api_client.dart';
import '../models/project.dart';
 
class ProjectService {
  final ApiClient _client;
 
  ProjectService(this._client);
 
  Future<List<Project>> getAll({int? limit, int? offset}) async {
    var path = '/api/v1/projects';
    final params = <String>[];
    if (limit != null) params.add('limit=$limit');
    if (offset != null) params.add('offset=$offset');
    if (params.isNotEmpty) path += '?${params.join('&')}';
 
    final data = await _client.get(path);
    return (data['data'] as List).map((p) => Project.fromJson(p)).toList();
  }
 
  Future<Project> getById(String id, {bool includeTasks = false}) async {
    var path = '/api/v1/projects/$id';
    if (includeTasks) path += '?include=tasks';
 
    final data = await _client.get(path);
    return Project.fromJson(data);
  }
 
  Future<Project> create({
    required String name,
    String? description,
  }) async {
    final data = await _client.post('/api/v1/projects', {
      'name': name,
      if (description != null) 'description': description,
    });
    return Project.fromJson(data);
  }
 
  Future<Project> update(String id, {String? name, String? description}) async {
    final data = await _client.patch('/api/v1/projects/$id', {
      if (name != null) 'name': name,
      if (description != null) 'description': description,
    });
    return Project.fromJson(data);
  }
 
  Future<void> delete(String id) async {
    await _client.delete('/api/v1/projects/$id');
  }
}

// lib/providers/auth_provider.dart
import 'package:flutter/material.dart';
import '../services/api_client.dart';
 
class User {
  final String id;
  final String email;
  final String name;
 
  User({required this.id, required this.email, required this.name});
 
  factory User.fromJson(Map<String, dynamic> json) {
    return User(id: json['id'], email: json['email'], name: json['name']);
  }
}
 
class AuthProvider extends ChangeNotifier {
  final ApiClient _client;
  User? _user;
  bool _loading = true;
 
  AuthProvider(this._client);
 
  User? get user => _user;
  bool get loading => _loading;
  bool get isAuthenticated => _user != null;
 
  Future<void> init() async {
    await _client.init();
    try {
      final data = await _client.get('/api/v1/auth/me');
      _user = User.fromJson(data);
    } catch (_) {
      // Not authenticated
    }
    _loading = false;
    notifyListeners();
  }
 
  Future<void> login(String email, String password) async {
    final data = await _client.post('/api/v1/auth/login', {
      'email': email,
      'password': password,
    });
    await _client.setToken(data['token']);
    _user = User.fromJson(data['user']);
    notifyListeners();
  }
 
  Future<void> logout() async {
    await _client.clearToken();
    _user = null;
    notifyListeners();
  }
}

// lib/providers/projects_provider.dart
import 'package:flutter/material.dart';
import '../models/project.dart';
import '../services/project_service.dart';
 
class ProjectsProvider extends ChangeNotifier {
  final ProjectService _service;
  List<Project> _projects = [];
  bool _loading = false;
  String? _error;
 
  ProjectsProvider(this._service);
 
  List<Project> get projects => _projects;
  bool get loading => _loading;
  String? get error => _error;
 
  Future<void> fetchProjects() async {
    _loading = true;
    _error = null;
    notifyListeners();
 
    try {
      _projects = await _service.getAll();
    } catch (e) {
      _error = e.toString();
    }
 
    _loading = false;
    notifyListeners();
  }
 
  Future<void> createProject(String name, String? description) async {
    final project = await _service.create(
      name: name,
      description: description,
    );
    _projects.insert(0, project);
    notifyListeners();
  }
 
  Future<void> deleteProject(String id) async {
    await _service.delete(id);
    _projects.removeWhere((p) => p.id == id);
    notifyListeners();
  }
}

// lib/screens/projects_screen.dart
import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import '../providers/projects_provider.dart';
 
class ProjectsScreen extends StatefulWidget {
  @override
  _ProjectsScreenState createState() => _ProjectsScreenState();
}
 
class _ProjectsScreenState extends State<ProjectsScreen> {
  @override
  void initState() {
    super.initState();
    context.read<ProjectsProvider>().fetchProjects();
  }
 
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text('Projects')),
      body: Consumer<ProjectsProvider>(
        builder: (context, provider, _) {
          if (provider.loading) {
            return Center(child: CircularProgressIndicator());
          }
          if (provider.error != null) {
            return Center(child: Text('Error: ${provider.error}'));
          }
          return RefreshIndicator(
            onRefresh: provider.fetchProjects,
            child: ListView.builder(
              itemCount: provider.projects.length,
              itemBuilder: (context, index) {
                final project = provider.projects[index];
                return ListTile(
                  title: Text(project.name),
                  subtitle: Text(project.description ?? ''),
                  onTap: () => Navigator.pushNamed(
                    context,
                    '/project',
                    arguments: project.id,
                  ),
                );
              },
            ),
          );
        },
      ),
      floatingActionButton: FloatingActionButton(
        child: Icon(Icons.add),
        onPressed: () => Navigator.pushNamed(context, '/create-project'),
      ),
    );
  }
}

// lib/screens/create_project_screen.dart
import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import '../providers/projects_provider.dart';
 
class CreateProjectScreen extends StatefulWidget {
  @override
  _CreateProjectScreenState createState() => _CreateProjectScreenState();
}
 
class _CreateProjectScreenState extends State<CreateProjectScreen> {
  final _formKey = GlobalKey<FormState>();
  final _nameController = TextEditingController();
  final _descriptionController = TextEditingController();
  bool _loading = false;
 
  Future<void> _submit() async {
    if (!_formKey.currentState!.validate()) return;
 
    setState(() => _loading = true);
    try {
      await context.read<ProjectsProvider>().createProject(
        _nameController.text,
        _descriptionController.text.isNotEmpty
            ? _descriptionController.text
            : null,
      );
      Navigator.pop(context);
    } catch (e) {
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(content: Text('Error: $e')),
      );
    }
    setState(() => _loading = false);
  }
 
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text('Create Project')),
      body: Form(
        key: _formKey,
        child: Padding(
          padding: EdgeInsets.all(16),
          child: Column(
            children: [
              TextFormField(
                controller: _nameController,
                decoration: InputDecoration(labelText: 'Name'),
                validator: (v) => v!.isEmpty ? 'Required' : null,
              ),
              SizedBox(height: 16),
              TextFormField(
                controller: _descriptionController,
                decoration: InputDecoration(labelText: 'Description'),
                maxLines: 3,
              ),
              SizedBox(height: 24),
              ElevatedButton(
                onPressed: _loading ? null : _submit,
                child: _loading
                    ? CircularProgressIndicator()
                    : Text('Create'),
              ),
            ],
          ),
        ),
      ),
    );
  }
}

// lib/main.dart
import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import 'services/api_client.dart';
import 'services/project_service.dart';
import 'providers/auth_provider.dart';
import 'providers/projects_provider.dart';
 
void main() async {
  WidgetsFlutterBinding.ensureInitialized();
 
  final apiClient = ApiClient();
  final authProvider = AuthProvider(apiClient);
  await authProvider.init();
 
  runApp(
    MultiProvider(
      providers: [
        ChangeNotifierProvider.value(value: authProvider),
        ChangeNotifierProvider(
          create: (_) => ProjectsProvider(ProjectService(apiClient)),
        ),
      ],
      child: MyApp(),
    ),
  );
}