// Version: 3.0 - シンプル製品マスタ画面（簡素版、サンプルデータ固定）

import 'package:flutter/material.dart';
import '../../models/product.dart';

class ProductMasterScreen extends StatefulWidget {
  const ProductMasterScreen({super.key});

  @override
  State<ProductMasterScreen> createState() => _ProductMasterScreenState();
}

class _ProductMasterScreenState extends State<ProductMasterScreen> {
  List<Product> _products = [];

  @override
  void initState() {
    super.initState();
    // サンプルデータ（簡素版）
    _products = <Product>[
      Product(productCode: 'P001', name: 'サンプル商品 A', unitPrice: 1000.0, stock: 50),
      Product(productCode: 'P002', name: 'サンプル商品 B', unitPrice: 2500.0, stock: 30),
    ];
  }

  Future<void> _addProduct() async {
    await showDialog<Product>(
      context: context,
      builder: (ctx) => AlertDialog(
        title: const Text('新規製品登録'),
        content: SingleChildScrollView(
          child: Column(
            mainAxisSize: MainAxisSize.min,
            crossAxisAlignment: CrossAxisAlignment.stretch,
            children: [
              TextField(decoration: const InputDecoration(labelText: 'コード', hintText: 'P003')),
              SizedBox(height: 8),
              TextField(decoration: const InputDecoration(labelText: '名称', hintText: '新製品名'), onChanged: (v) => setState(() {})),
              SizedBox(height: 8),
              TextField(decoration: const InputDecoration(labelText: '単価', hintText: '1500.0'), keyboardType: TextInputType.number, onChanged: (v) => setState(() {})),
              SizedBox(height: 8),
              TextField(decoration: const InputDecoration(labelText: '在庫', hintText: '10'), keyboardType: TextInputType.number, onChanged: (v) => setState(() {})),
            ],
          ),
        ),
        actions: [
          TextButton(onPressed: () => Navigator.pop(ctx), child: const Text('キャンセル')),
          ElevatedButton(
            onPressed: () {
              Navigator.pop(ctx);
            },
            child: const Text('登録'),
          ),
        ],
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('/M3. 製品マスタ')),
      body: _products.isEmpty ? Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            Icon(Icons.inbox_outlined, size: 64, color: Colors.grey[300]),
            SizedBox(height: 16),
            Text('製品データがありません', style: TextStyle(color: Colors.grey)),
            SizedBox(height: 16),
            FloatingActionButton.extended(
              icon: Icon(Icons.add, color: Theme.of(context).primaryColor),
              label: const Text('新規登録'),
              onPressed: _addProduct,
            ),
          ],
        ),
      ) : ListView.builder(
        padding: const EdgeInsets.all(8),
        itemCount: _products.length,
        itemBuilder: (context, index) {
          final product = _products[index];
          return Card(
            margin: EdgeInsets.zero,
            clipBehavior: Clip.antiAlias,
            child: ListTile(
              leading: CircleAvatar(backgroundColor: Colors.blue.shade100, child: Text(product.productCode ?? '-', style: const TextStyle(fontWeight: FontWeight.bold))),
              title: Text(product.name ?? '未入力'),
              subtitle: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  if (product.stock > 0) Text('在庫：${product.stock}個', style: const TextStyle(fontSize: 12)),
                  Text('単価：¥${product.unitPrice}', style: const TextStyle(fontSize: 12)),
                ],
              ),
            ),
          );
        },
      ),
      floatingActionButton: FloatingActionButton.extended(
        icon: const Icon(Icons.add),
        label: const Text('新規登録'),
        onPressed: _addProduct,
      ),
    );
  }
}