Comprehensive comparison for technology in applications

import 'package:flutter/material.dart';
import 'package:http/http.dart' as http;
import 'dart:convert';

// Model class for Product
class Product {
  final int id;
  final String name;
  final double price;
  final String imageUrl;

  Product({
    required this.id,
    required this.name,
    required this.price,
    required this.imageUrl,
  });

  factory Product.fromJson(Map<String, dynamic> json) {
    return Product(
      id: json['id'] ?? 0,
      name: json['name'] ?? 'Unknown Product',
      price: (json['price'] ?? 0).toDouble(),
      imageUrl: json['imageUrl'] ?? '',
    );
  }
}

// Service class for API calls
class ProductService {
  static const String baseUrl = 'https://api.example.com';

  Future<List<Product>> fetchProducts() async {
    try {
      final response = await http.get(
        Uri.parse('$baseUrl/products'),
        headers: {'Content-Type': 'application/json'},
      ).timeout(const Duration(seconds: 10));

      if (response.statusCode == 200) {
        final List<dynamic> jsonData = json.decode(response.body);
        return jsonData.map((json) => Product.fromJson(json)).toList();
      } else {
        throw Exception('Failed to load products: ${response.statusCode}');
      }
    } catch (e) {
      throw Exception('Network error: $e');
    }
  }
}

// StatefulWidget for Product List Screen
class ProductListScreen extends StatefulWidget {
  const ProductListScreen({Key? key}) : super(key: key);

  @override
  State<ProductListScreen> createState() => _ProductListScreenState();
}

class _ProductListScreenState extends State<ProductListScreen> {
  final ProductService _productService = ProductService();
  List<Product> _products = [];
  bool _isLoading = true;
  String? _errorMessage;

  @override
  void initState() {
    super.initState();
    _loadProducts();
  }

  Future<void> _loadProducts() async {
    setState(() {
      _isLoading = true;
      _errorMessage = null;
    });

    try {
      final products = await _productService.fetchProducts();
      setState(() {
        _products = products;
        _isLoading = false;
      });
    } catch (e) {
      setState(() {
        _errorMessage = e.toString();
        _isLoading = false;
      });
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Products'),
        actions: [
          IconButton(
            icon: const Icon(Icons.refresh),
            onPressed: _loadProducts,
          ),
        ],
      ),
      body: _buildBody(),
    );
  }

  Widget _buildBody() {
    if (_isLoading) {
      return const Center(child: CircularProgressIndicator());
    }

    if (_errorMessage != null) {
      return Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            const Icon(Icons.error_outline, size: 48, color: Colors.red),
            const SizedBox(height: 16),
            Text(_errorMessage!, textAlign: TextAlign.center),
            const SizedBox(height: 16),
            ElevatedButton(
              onPressed: _loadProducts,
              child: const Text('Retry'),
            ),
          ],
        ),
      );
    }

    if (_products.isEmpty) {
      return const Center(child: Text('No products available'));
    }

    return RefreshIndicator(
      onRefresh: _loadProducts,
      child: ListView.builder(
        itemCount: _products.length,
        itemBuilder: (context, index) {
          final product = _products[index];
          return ListTile(
            leading: Image.network(
              product.imageUrl,
              width: 50,
              height: 50,
              fit: BoxFit.cover,
              errorBuilder: (context, error, stackTrace) {
                return const Icon(Icons.image_not_supported);
              },
            ),
            title: Text(product.name),
            subtitle: Text('\$${product.price.toStringAsFixed(2)}'),
            trailing: const Icon(Icons.arrow_forward_ios),
            onTap: () {
              // Navigate to product details
              ScaffoldMessenger.of(context).showSnackBar(
                SnackBar(content: Text('Selected: ${product.name}')),
              );
            },
          );
        },
      ),
    );
  }
}