Refactor: Separate UI screens into

lib/main.dart

@@ -1,6 +1,12 @@
 import 'package:flutter/material.dart';
+import 'package:sqflite_common_ffi/sqflite_ffi.dart';
+import 'screens/product_list_screen.dart';
+import 'screens/add_edit_product_screen.dart';
 
-void main() {
+void main() async {
+  WidgetsFlutterBinding.ensureInitialized();
+  sqfliteFfiInit();
+  databaseFactory = databaseFactoryFfi;
   runApp(const MyApp());
 }
 
@@ -10,34 +16,12 @@ class MyApp extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     return MaterialApp(
-      title: 'Flutter Demo',
+      title: 'ابزار ساده ثبت کالا',
       theme: ThemeData(
-        colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
+        primarySwatch: Colors.blueGrey,
+        visualDensity: VisualDensity.adaptivePlatformDensity,
       ),
-      home: const MyHomePage(title: 'Flutter Demo Home Page'),
-    );
-  }
-}
-
-class MyHomePage extends StatefulWidget {
-  const MyHomePage({super.key, required this.title});
-
-  final String title;
-
-  @override
-  State<MyHomePage> createState() => _MyHomePageState();
-}
-
-class _MyHomePageState extends State<MyHomePage> {
-  @override
-  Widget build(BuildContext context) {
-    return Scaffold(
-      appBar: AppBar(
-        backgroundColor: Theme.of(context).colorScheme.inversePrimary,
-
-        title: Text(widget.title),
-      ),
-      body: Center(),
+      home: ProductListScreen(),
     );
   }
 }

lib/screens/add_edit_product_screen.dart

@@ -0,0 +1,162 @@
+import 'package:flutter/material.dart';
+import '../models/product.dart';
+import '../services/database_helper.dart';
+
+class AddEditProductScreen extends StatefulWidget {
+  final Product? product;
+
+  const AddEditProductScreen({super.key, this.product});
+
+  @override
+  State<AddEditProductScreen> createState() => _AddEditProductScreenState();
+}
+
+class _AddEditProductScreenState extends State<AddEditProductScreen> {
+  final _formKey = GlobalKey<FormState>();
+  late TextEditingController _nameController;
+  late TextEditingController _codeController;
+  late TextEditingController _quantityController;
+  late TextEditingController _priceController;
+  late TextEditingController _descriptionController;
+  late DatabaseHelper _databaseHelper;
+
+  bool get isEditing => widget.product != null;
+
+  @override
+  void initState() {
+    super.initState();
+    _databaseHelper = DatabaseHelper();
+    _nameController = TextEditingController(text: widget.product?.name);
+    _codeController = TextEditingController(text: widget.product?.code);
+    _quantityController = TextEditingController(
+      text: widget.product?.quantity.toString(),
+    );
+    _priceController = TextEditingController(
+      text: widget.product?.price.toString(),
+    );
+    _descriptionController = TextEditingController(
+      text: widget.product?.description,
+    );
+  }
+
+  @override
+  void dispose() {
+    _nameController.dispose();
+    _codeController.dispose();
+    _quantityController.dispose();
+    _priceController.dispose();
+    _descriptionController.dispose();
+    super.dispose();
+  }
+
+  Future<void> _saveProduct() async {
+    if (_formKey.currentState!.validate()) {
+      _formKey.currentState!.save();
+
+      final product = Product(
+        id: isEditing ? widget.product!.id : null,
+        name: _nameController.text,
+        code: _codeController.text,
+        quantity: int.parse(_quantityController.text),
+        price: double.parse(_priceController.text),
+        description:
+            _descriptionController.text.isEmpty
+                ? null
+                : _descriptionController.text,
+      );
+
+      if (isEditing) {
+        await _databaseHelper.updateProduct(product);
+      } else {
+        await _databaseHelper.insertProduct(product);
+      }
+
+      if (!mounted) return;
+      Navigator.pop(context, true);
+    }
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(
+        title: Text(isEditing ? 'ویرایش کالا' : 'افزودن کالا'),
+        centerTitle: true,
+      ),
+      body: Padding(
+        padding: const EdgeInsets.all(16.0),
+        child: Form(
+          key: _formKey,
+          child: ListView(
+            children: [
+              TextFormField(
+                controller: _nameController,
+                decoration: const InputDecoration(labelText: 'نام کالا'),
+                validator: (value) {
+                  if (value == null || value.isEmpty) {
+                    return 'لطفا نام کالا را وارد کنید';
+                  }
+                  return null;
+                },
+              ),
+              const SizedBox(height: 10),
+              TextFormField(
+                controller: _codeController,
+                decoration: const InputDecoration(labelText: 'کد کالا'),
+                validator: (value) {
+                  if (value == null || value.isEmpty) {
+                    return 'لطفا کد کالا را وارد کنید';
+                  }
+                  return null;
+                },
+              ),
+              const SizedBox(height: 10),
+              TextFormField(
+                controller: _quantityController,
+                decoration: const InputDecoration(labelText: 'تعداد'),
+                keyboardType: TextInputType.number,
+                validator: (value) {
+                  if (value == null || value.isEmpty) {
+                    return 'لطفا تعداد را وارد کنید';
+                  }
+                  if (int.tryParse(value) == null) {
+                    return 'تعداد باید عدد باشد';
+                  }
+                  return null;
+                },
+              ),
+              const SizedBox(height: 10),
+              TextFormField(
+                controller: _priceController,
+                decoration: const InputDecoration(labelText: 'قیمت'),
+                keyboardType: TextInputType.number,
+                validator: (value) {
+                  if (value == null || value.isEmpty) {
+                    return 'لطفا قیمت را وارد کنید';
+                  }
+                  if (double.tryParse(value) == null) {
+                    return 'قیمت باید عدد باشد';
+                  }
+                  return null;
+                },
+              ),
+              const SizedBox(height: 10),
+              TextFormField(
+                controller: _descriptionController,
+                decoration: const InputDecoration(
+                  labelText: 'توضیحات (اختیاری)',
+                ),
+                maxLines: 3,
+              ),
+              const SizedBox(height: 20),
+              ElevatedButton(
+                onPressed: _saveProduct,
+                child: Text(isEditing ? 'ذخیره تغییرات' : 'افزودن کالا'),
+              ),
+            ],
+          ),
+        ),
+      ),
+    );
+  }
+}

lib/screens/product_list_screen.dart

@@ -0,0 +1,139 @@
+import 'package:flutter/material.dart';
+import '../services/database_helper.dart';
+import '../models/product.dart';
+import 'add_edit_product_screen.dart';
+
+class ProductListScreen extends StatefulWidget {
+  const ProductListScreen({super.key});
+
+  @override
+  State<ProductListScreen> createState() => _ProductListScreenState();
+}
+
+class _ProductListScreenState extends State<ProductListScreen> {
+  late DatabaseHelper _databaseHelper;
+  List<Product> _products = [];
+  bool _isLoading = true;
+
+  @override
+  void initState() {
+    super.initState();
+    _databaseHelper = DatabaseHelper();
+    _loadProducts();
+  }
+
+  Future<void> _loadProducts() async {
+    setState(() {
+      _isLoading = true;
+    });
+    final products = await _databaseHelper.getProducts();
+    if (!mounted) return;
+    setState(() {
+      _products = products;
+      _isLoading = false;
+    });
+  }
+
+  Future<void> _deleteProduct(int id) async {
+    await _databaseHelper.deleteProduct(id);
+    _loadProducts();
+  }
+
+  void _navigateToAddEditProduct([Product? product]) async {
+    final result = await Navigator.push(
+      context,
+      MaterialPageRoute(
+        builder: (context) => AddEditProductScreen(product: product),
+      ),
+    );
+
+    if (!mounted) return;
+    if (result == true) {
+      _loadProducts();
+    }
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(title: const Text('لیست کالاها'), centerTitle: true),
+      body:
+          _isLoading
+              ? const Center(child: CircularProgressIndicator())
+              : _products.isEmpty
+              ? const Center(
+                child: Text(
+                  'هیچ کالایی یافت نشد. برای شروع، یک کالا اضافه کنید.',
+                ),
+              )
+              : ListView.builder(
+                itemCount: _products.length,
+                itemBuilder: (context, index) {
+                  final product = _products[index];
+                  return Card(
+                    margin: const EdgeInsets.symmetric(
+                      horizontal: 10,
+                      vertical: 5,
+                    ),
+                    child: ListTile(
+                      leading: CircleAvatar(
+                        child: Text(product.quantity.toString()),
+                      ),
+                      title: Text(product.name),
+                      subtitle: Text(
+                        'کد: ${product.code} | قیمت: ${product.price} تومان',
+                      ),
+                      trailing: Row(
+                        mainAxisSize: MainAxisSize.min,
+                        children: [
+                          IconButton(
+                            icon: const Icon(Icons.edit, color: Colors.blue),
+                            onPressed: () => _navigateToAddEditProduct(product),
+                          ),
+                          IconButton(
+                            icon: const Icon(Icons.delete, color: Colors.red),
+                            onPressed: () {
+                              showDialog(
+                                context: context,
+                                builder:
+                                    (context) => AlertDialog(
+                                      title: const Text('حذف کالا'),
+                                      content: Text(
+                                        'آیا مطمئنید که می‌خواهید ${product.name} را حذف کنید؟',
+                                      ),
+                                      actions: [
+                                        TextButton(
+                                          onPressed:
+                                              () => Navigator.pop(context),
+                                          child: const Text('خیر'),
+                                        ),
+                                        TextButton(
+                                          onPressed: () {
+                                            _deleteProduct(product.id!);
+                                            if (!mounted)
+                                              return; // Add this check
+                                            Navigator.pop(context);
+                                          },
+                                          child: const Text('بله'),
+                                        ),
+                                      ],
+                                    ),
+                              );
+                            },
+                          ),
+                        ],
+                      ),
+                      onTap: () {
+                        _navigateToAddEditProduct(product);
+                      },
+                    ),
+                  );
+                },
+              ),
+      floatingActionButton: FloatingActionButton(
+        onPressed: () => _navigateToAddEditProduct(),
+        child: const Icon(Icons.add),
+      ),
+    );
+  }
+}