// Version: 1.0.0
import 'package:flutter/material.dart';

/// 売上入力画面（レジモードの主戦場）（Material Design テンプレート）
class SalesScreen extends StatelessWidget {
  const SalesScreen({super.key});

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('売上入力'),
        actions: [
          IconButton(
            icon: const Icon(Icons.receipt_long),
            onPressed: () => _showSaveDialog(context),
          ),
        ],
      ),
      body: ListView(
        padding: const EdgeInsets.all(16),
        children: [
          // レジモードのメイン表示エリア
          Card(
            margin: EdgeInsets.zero,
            child: Padding(
              padding: const EdgeInsets.all(16),
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.stretch,
                children: [
                  // 合計金額表示
                  Text(
                    '合計：¥0',
                    style: const TextStyle(
                      fontSize: 32,
                      fontWeight: FontWeight.bold,
                      color: Colors.black87,
                    ),
                  ),
                  const SizedBox(height: 16),

                  // 税率/税額表示
                  Row(
                    mainAxisAlignment: MainAxisAlignment.spaceBetween,
                    children: [
                      Text('税別：¥0'),
                      Text('税込：¥0', style: const TextStyle(fontWeight: FontWeight.bold)),
                    ],
                  ),
                ],
              ),
            ),
          ),

          const SizedBox(height: 16),

          // 商品入力エリア
          TextField(
            decoration: const InputDecoration(
              labelText: '商品検索',
              hintText: 'JAN コードまたは商品名を入力',
              prefixIcon: Icon(Icons.search),
            ),
            onChanged: (value) { /* TODO: 商品検索 */ },
          ),

          const SizedBox(height: 16),

          // 商品リスト
          Card(
            margin: EdgeInsets.zero,
            child: ExpansionTile(
              title: const Text('売上商品'),
              children: [
                ListView.builder(
                  shrinkWrap: true,
                  padding: EdgeInsets.zero,
                  itemCount: 0, // デモ用
                  itemBuilder: (context, index) => Card(
                    margin: const EdgeInsets.symmetric(vertical: 4),
                    child: ListTile(
                      leading: CircleAvatar(
                        backgroundColor: Colors.orange.shade100,
                        child: Icon(Icons.store, color: Colors.orange),
                      ),
                      title: Text('商品${index + 1}'),
                      subtitle: Text('数量：0 pcs / 単価：¥0'),
                    ),
                  ),
                ),
              ],
            ),
          ),
        ],
      ),
    );
  }

  void _showSaveDialog(BuildContext context) {
    showDialog(
      context: context,
      builder: (ctx) => AlertDialog(
        title: const Text('売上確定'),
        content: SingleChildScrollView(
          child: Column(
            mainAxisSize: MainAxisSize.min,
            children: [
              Text('売上データを保存しますか？'),
            ],
          ),
        ),
        actions: [
          TextButton(
            onPressed: () => Navigator.pop(ctx),
            child: const Text('キャンセル'),
          ),
          ElevatedButton(
            onPressed: () {
              Navigator.pop(ctx);
              ScaffoldMessenger.of(context).showSnackBar(
                const SnackBar(content: Text('売上保存しました')),
              );
            },
            style: ElevatedButton.styleFrom(backgroundColor: Colors.green),
            child: const Text('確定'),
          ),
        ],
      ),
    );
  }

  void _showCustomerPicker(BuildContext context) {
    // TODO: CustomerPickerModal を再利用して実装
  }
}