Demo version

app.py

@@ -6,20 +6,19 @@ from datetime import datetime
 import requests
 
 # Hugging Face API configuration
-HF_API_URL = "https://api-inference.huggingface.co/models/microsoft/DialoGPT-small"
+HF_API_URL = "https://api-inference.huggingface.co/models/Qwen/Qwen3-0.6B"
 HF_TOKEN = os.environ.get("HF_TOKEN")  # Will be set in Hugging Face Spaces
 
-def generate_code_with_ai(prompt, max_length=500):
-    """Generate code using the Hugging Face Inference API."""
+def generate_code_with_ai(prompt, max_length=800):
+    """Generate code using the Hugging Face Inference API with Qwen model."""
     try:
-        # Create a more specific prompt for Flutter/Dart code
-        full_prompt = f"""Write clean Flutter Dart code for this requirement: {prompt}
+        # Create a more specific prompt for Flutter/Dart code using Qwen's strengths
+        full_prompt = f"""You are an expert Flutter developer. Generate clean, working Dart code for this requirement:
 
-Generate proper Dart classes, methods, and Flutter widgets. Focus on:
-- Clean, readable code
-- Proper Flutter/Dart syntax
-- Material Design patterns
-- Error handling where appropriate
+{prompt}
+
+IMPORTANT: Provide ONLY the Dart code without any explanations or markdown formatting.
+The code should be complete, functional, and follow Flutter best practices.
 
 ```dart
 """
@@ -30,14 +29,16 @@ Generate proper Dart classes, methods, and Flutter widgets. Focus on:
             "inputs": full_prompt,
             "parameters": {
                 "max_length": max_length,
-                "temperature": 0.7,
+                "temperature": 0.3,  # Lower temperature for more focused code generation
                 "do_sample": True,
                 "return_full_text": False,
                 "num_return_sequences": 1,
+                "top_p": 0.9,  # Better sampling for code
+                "repetition_penalty": 1.1,  # Reduce repetition
             }
         }
 
-        response = requests.post(HF_API_URL, headers=headers, json=payload)
+        response = requests.post(HF_API_URL, headers=headers, json=payload, timeout=30)
         response.raise_for_status()
 
         result = response.json()
@@ -59,6 +60,9 @@ Generate proper Dart classes, methods, and Flutter widgets. Focus on:
         # Remove any remaining markdown formatting
         code = code.replace("```", "").strip()
 
+        # Additional cleanup for common issues
+        code = code.replace("dart\n", "").replace("Dart\n", "")
+
         return code if code else "// AI-generated placeholder code"
 
     except Exception as e:
@@ -150,21 +154,23 @@ def generate_flutter_code(description):
 
 
 def generate_main_dart(description):
-    """Generate the main.dart file content using AI."""
-    prompt = f"""Create a Flutter main.dart file for an app described as: {description}
-
-The main.dart should include:
-- Material Design theme
-- A basic home page
-- Proper imports
-- Clean, modern Flutter code structure
-
+    """Generate the main.dart file content using Qwen AI."""
+    prompt = f"""Generate a complete Flutter main.dart file for: {description}
+
+Requirements:
+1. Import necessary packages (flutter/material.dart)
+2. Create main() function
+3. Create MyApp widget extending StatelessWidget
+4. Include MaterialApp with proper theme
+5. Create a basic HomePage widget
+6. Include app bar and basic layout
+7. Use modern Flutter syntax with const constructors
+
+Code structure:
 ```dart
 import 'package:flutter/material.dart';
 
-void main() {{
-  runApp(const MyApp());
-}}
+void main() => runApp(const MyApp());
 
 class MyApp extends StatelessWidget {{
   const MyApp({{super.key}});
@@ -172,35 +178,27 @@ class MyApp extends StatelessWidget {{
   @override
   Widget build(BuildContext context) {{
     return MaterialApp(
-      title: 'Flutter App',
-      theme: ThemeData(
-        primarySwatch: Colors.blue,
-        useMaterial3: true,
-      ),
+      title: 'Generated App',
+      theme: ThemeData(primarySwatch: Colors.blue, useMaterial3: true),
       home: const HomePage(),
     );
   }}
 }}
 
-class HomePage extends StatefulWidget {{
+class HomePage extends StatelessWidget {{
   const HomePage({{super.key}});
 
-  @override
-  State<HomePage> createState() => _HomePageState();
-}}
-
-class _HomePageState extends State<HomePage> {{
   @override
   Widget build(BuildContext context) {{
     return Scaffold(
       appBar: AppBar(title: const Text('Home')),
-      body: const Center(child: Text('Hello World')),
+      body: const Center(child: Text('Welcome to your app!')),
     );
   }}
 }}
 ```"""
 
-    ai_generated_code = generate_code_with_ai(prompt, max_length=800)
+    ai_generated_code = generate_code_with_ai(prompt, max_length=1000)
 
     # Add header comment
     header = f"""// AI-Generated Flutter Application
@@ -214,80 +212,78 @@ class _HomePageState extends State<HomePage> {{
 
 
 def generate_widgets_dart(description):
-    """Generate the widgets.dart file content using AI."""
-    prompt = f"""Create Flutter custom widgets for an app described as: {description}
+    """Generate the widgets.dart file content using Qwen AI."""
+    prompt = f"""Generate Flutter custom widgets for: {description}
+
+Create at least 3 reusable widgets with proper documentation:
 
-Create at least 3 reusable widgets including:
-- A custom card/info widget
-- A custom button widget
-- A custom input field widget
+1. CustomInfoCard - A styled card widget for displaying information
+2. CustomButton - An enhanced button with loading states
+3. CustomTextField - A styled text input field
+
+Requirements:
+- Use proper Dart documentation comments (///)
+- Include null safety and const constructors
 - Follow Material Design guidelines
-- Include proper documentation
+- Include proper parameter validation
+- Use modern Flutter patterns
 
+Example structure:
 ```dart
 import 'package:flutter/material.dart';
 
-/// Custom info card widget
+/// Custom info card widget for displaying content
 class CustomInfoCard extends StatelessWidget {{
   final String title;
   final String description;
   final IconData? icon;
+  final Color? backgroundColor;
 
   const CustomInfoCard({{
     super.key,
     required this.title,
     required this.description,
     this.icon,
+    this.backgroundColor,
   }});
 
   @override
   Widget build(BuildContext context) {{
     return Card(
       elevation: 4,
+      color: backgroundColor,
       margin: const EdgeInsets.all(16),
       child: Padding(
         padding: const EdgeInsets.all(20),
         child: Column(
           mainAxisSize: MainAxisSize.min,
           children: [
-            if (icon != null) Icon(icon, size: 48),
-            if (icon != null) const SizedBox(height: 12),
-            Text(title, style: Theme.of(context).textTheme.headlineSmall),
+            if (icon != null) ...[
+              Icon(icon, size: 48, color: Theme.of(context).primaryColor),
+              const SizedBox(height: 12),
+            ],
+            Text(
+              title,
+              style: Theme.of(context).textTheme.headlineSmall?.copyWith(
+                fontWeight: FontWeight.bold,
+              ),
+              textAlign: TextAlign.center,
+            ),
             const SizedBox(height: 8),
-            Text(description, style: Theme.of(context).textTheme.bodyMedium),
+            Text(
+              description,
+              style: Theme.of(context).textTheme.bodyMedium,
+              textAlign: TextAlign.center,
+            ),
           ],
         ),
       ),
     );
   }}
 }}
-
-/// Custom button with loading state
-class CustomButton extends StatelessWidget {{
-  final String text;
-  final VoidCallback? onPressed;
-  final bool isLoading;
-
-  const CustomButton({{
-    super.key,
-    required this.text,
-    this.onPressed,
-    this.isLoading = false,
-  }});
-
-  @override
-  Widget build(BuildContext context) {{
-    return ElevatedButton(
-      onPressed: isLoading ? null : onPressed,
-      child: isLoading
-          ? const CircularProgressIndicator()
-          : Text(text),
-    );
-  }}
-}}
 ```"""
 
-    ai_generated_code = generate_code_with_ai(prompt, max_length=1000)
+    ai_generated_code = generate_code_with_ai(prompt, max_length=1200)
 
     # Add header comment
     header = f"""// Custom Widgets for the Flutter Application
@@ -301,91 +297,91 @@ class CustomButton extends StatelessWidget {{
 
 
 def generate_models_dart(description):
-    """Generate the models.dart file content using AI."""
-    prompt = f"""Create Flutter data models for an app described as: {description}
-
-Create data models with:
-- Proper Dart class structure
-- JSON serialization methods (toJson/fromJson)
-- CopyWith methods for immutability
-- Proper type annotations
-- At least 2-3 relevant models based on the app description
-
+    """Generate the models.dart file content using Qwen AI."""
+    prompt = f"""Generate Flutter data models for: {description}
+
+Create comprehensive data models with:
+1. Proper class structure with const constructors
+2. JSON serialization (toJson/fromJson)
+3. CopyWith methods for immutable updates
+4. Proper type annotations and null safety
+5. Documentation comments
+6. At least 2-3 models relevant to the app
+
+Requirements:
+- Use final fields for immutability
+- Include proper error handling in fromJson
+- Add copyWith for state management
+- Use meaningful field names
+
+Example structure:
 ```dart
-/// Base item model
+/// Represents a task or item in the application
 class Item {{
   final String id;
   final String title;
   final String description;
   final DateTime createdAt;
+  final DateTime? updatedAt;
   final bool isCompleted;
+  final String? category;
 
   const Item({{
     required this.id,
     required this.title,
     required this.description,
     required this.createdAt,
+    this.updatedAt,
     this.isCompleted = false,
+    this.category,
   }});
 
+  /// Convert to JSON for storage/API calls
   Map<String, dynamic> toJson() => {{
     'id': id,
     'title': title,
     'description': description,
     'createdAt': createdAt.toIso8601String(),
+    'updatedAt': updatedAt?.toIso8601String(),
     'isCompleted': isCompleted,
+    'category': category,
   }};
 
+  /// Create from JSON data
   factory Item.fromJson(Map<String, dynamic> json) => Item(
-    id: json['id'],
-    title: json['title'],
-    description: json['description'],
-    createdAt: DateTime.parse(json['createdAt']),
-    isCompleted: json['isCompleted'] ?? false,
+    id: json['id'] as String? ?? '',
+    title: json['title'] as String? ?? '',
+    description: json['description'] as String? ?? '',
+    createdAt: DateTime.tryParse(json['createdAt'] as String? ?? '') ?? DateTime.now(),
+    updatedAt: json['updatedAt'] != null
+        ? DateTime.tryParse(json['updatedAt'] as String)
+        : null,
+    isCompleted: json['isCompleted'] as bool? ?? false,
+    category: json['category'] as String?,
   );
 
+  /// Create a copy with updated fields
   Item copyWith({{
     String? id,
     String? title,
     String? description,
     DateTime? createdAt,
+    DateTime? updatedAt,
     bool? isCompleted,
+    String? category,
   }}) => Item(
     id: id ?? this.id,
     title: title ?? this.title,
     description: description ?? this.description,
     createdAt: createdAt ?? this.createdAt,
+    updatedAt: updatedAt ?? this.updatedAt,
     isCompleted: isCompleted ?? this.isCompleted,
-  );
-}}
-
-/// User model
-class User {{
-  final String id;
-  final String name;
-  final String email;
-
-  const User({{
-    required this.id,
-    required this.name,
-    required this.email,
-  }});
-
-  Map<String, dynamic> toJson() => {{
-    'id': id,
-    'name': name,
-    'email': email,
-  }};
-
-  factory User.fromJson(Map<String, dynamic> json) => User(
-    id: json['id'],
-    name: json['name'],
-    email: json['email'],
+    category: category ?? this.category,
   );
 }}
 ```"""
 
-    ai_generated_code = generate_code_with_ai(prompt, max_length=800)
+    ai_generated_code = generate_code_with_ai(prompt, max_length=1000)
 
     # Add header comment
     header = f"""// Data Models for the Flutter Application
@@ -399,30 +395,46 @@ class User {{
 
 
 def generate_services_dart(description):
-    """Generate the services.dart file content using AI."""
-    prompt = f"""Create Flutter service classes for an app described as: {description}
-
-Create service classes with:
-- Business logic methods
-- Data management operations (CRUD)
-- Validation utilities
-- Proper error handling
-- Based on the app requirements from the description
-
+    """Generate the services.dart file content using Qwen AI."""
+    prompt = f"""Generate Flutter service classes for: {description}
+
+Create comprehensive service classes with:
+1. DataService - For managing application data (CRUD operations)
+2. ValidationService - For input validation and utilities
+3. Proper error handling and state management
+4. Documentation comments
+5. Null safety and modern Dart patterns
+
+Requirements:
+- Use proper async/await patterns where applicable
+- Include error handling with try-catch blocks
+- Add meaningful method names and documentation
+- Use immutable data structures where possible
+
+Example structure:
 ```dart
+import 'dart:convert';
 import 'models.dart';
 
-/// Data service for managing application data
+/// Service for managing application data and business logic
 class DataService {{
   final List<Item> _items = [];
 
-  /// Get all items
+  /// Get all items (returns unmodifiable list)
   List<Item> getAllItems() => List.unmodifiable(_items);
 
-  /// Add new item
-  void addItem(Item item) => _items.add(item);
+  /// Get items by completion status
+  List<Item> getItems({{bool? completed}}) {{
+    if (completed == null) return getAllItems();
+    return _items.where((item) => item.isCompleted == completed).toList();
+  }}
+
+  /// Add a new item to the collection
+  void addItem(Item item) {{
+    _items.add(item);
+  }}
 
-  /// Update existing item
+  /// Update an existing item by ID
   bool updateItem(String id, Item updatedItem) {{
     final index = _items.indexWhere((item) => item.id == id);
     if (index != -1) {{
@@ -432,7 +444,7 @@ class DataService {{
     return false;
   }}
 
-  /// Delete item
+  /// Remove an item by ID
   bool deleteItem(String id) {{
     final index = _items.indexWhere((item) => item.id == id);
     if (index != -1) {{
@@ -442,34 +454,62 @@ class DataService {{
     return false;
   }}
 
-  /// Toggle completion status
-  bool toggleCompletion(String id) {{
+  /// Toggle completion status of an item
+  bool toggleItemCompletion(String id) {{
     final index = _items.indexWhere((item) => item.id == id);
     if (index != -1) {{
-      _items[index].isCompleted = !_items[index].isCompleted;
+      _items[index] = _items[index].copyWith(
+        isCompleted: !_items[index].isCompleted,
+        updatedAt: DateTime.now(),
+      );
       return true;
     }}
     return false;
   }}
+
+  /// Clear all items
+  void clearAll() {{
+    _items.clear();
+  }}
 }}
 
-/// Validation service with utility methods
+/// Utility service for validation and data processing
 class ValidationService {{
+  /// Validate email format using regex
   static bool isValidEmail(String email) {{
-    return RegExp(r'^[^@]+@[^@]+\\.[^@]+').hasMatch(email);
+    final emailRegex = RegExp(
+      r'^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z]{{2,}}$',
+    );
+    return emailRegex.hasMatch(email);
   }}
 
+  /// Check if string is not null or empty
   static bool isNotEmpty(String? value) {{
     return value != null && value.trim().isNotEmpty;
   }}
 
+  /// Check minimum length requirement
   static bool hasMinLength(String value, int minLength) {{
     return value.length >= minLength;
   }}
+
+  /// Validate item data before saving
+  static String? validateItem(Item item) {{
+    if (!isNotEmpty(item.title)) {{
+      return 'Title cannot be empty';
+    }}
+    if (!hasMinLength(item.title, 3)) {{
+      return 'Title must be at least 3 characters long';
+    }}
+    if (!isNotEmpty(item.description)) {{
+      return 'Description cannot be empty';
+    }}
+    return null; // No validation errors
+  }}
 }}
 ```"""
 
-    ai_generated_code = generate_code_with_ai(prompt, max_length=800)
+    ai_generated_code = generate_code_with_ai(prompt, max_length=1000)
 
     # Add header comment
     header = f"""// Business Logic and Services
@@ -715,7 +755,7 @@ def create_interface():
             - **README.md** - Setup and usage instructions
             
             ### ⚠️ Important Notes:
-            - This uses the **Hugging Face Inference API** for AI-powered code generation
+            - This uses **Qwen 3 0.6B** - a powerful AI model optimized for code generation
             - The AI generates Flutter/Dart code based on your description
             - Always review and test generated code before production use
             - The AI service may occasionally be slow or unavailable - try again if needed