// Version: 1.0.1 - Sprint 4-M2 実装開始
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.save),
            onPressed: () => _showSaveDialog(context),
          ),
        ],
      ),
      body: Column(
        children: [
          // ダッシュボードエリア（合計金額表示）
          Padding(
            padding: const EdgeInsets.all(16),
            child: Card(
              elevation: 4,
              child: Padding(
                padding: const EdgeInsets.all(16),
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.stretch,
                  children: [
                    // タイトル
                    Text(
                      'レジモード',
                      style: Theme.of(context).textTheme.titleLarge?.copyWith(
                            fontWeight: FontWeight.bold,
                          ),
                    ),
                    const SizedBox(height: 8),

                    // 合計金額表示
                    Row(
                      mainAxisAlignment: MainAxisAlignment.spaceBetween,
                      children: [
                        Text(
                          '合計',
                          style: TextStyle(
                            fontSize: 18,
                            color: Colors.grey.shade600,
                          ),
                        ),
                        const Icon(Icons.payments, size: 32),
                      ],
                    ),
                    const SizedBox(height: 4),

                    // 合計金額（大きな表示）
                    Text(
                      '¥0',
                      style: const TextStyle(
                        fontSize: 48,
                        fontWeight: FontWeight.bold,
                        color: Colors.teal,
                      ),
                    ),
                    const SizedBox(height: 16),

                    // 税率/税額表示
                    Row(
                      mainAxisAlignment: MainAxisAlignment.spaceBetween,
                      children: [
                        Column(
                          crossAxisAlignment: CrossAxisAlignment.start,
                          children: [
                            Text('税別', style: TextStyle(fontSize: 14)),
                            Text('¥0'),
                          ],
                        ),
                        Column(
                          crossAxisAlignment: CrossAxisAlignment.end,
                          children: [
                            Text('税込', style: TextStyle(fontWeight: FontWeight.bold)),
                            Text('¥0', style: const TextStyle(fontWeight: FontWeight.bold)),
                          ],
                        ),
                      ],
                    ),
                  ],
                ),
              ),
            ),
          ),

          // 商品入力エリア
          Padding(
            padding: const EdgeInsets.symmetric(horizontal: 16),
            child: TextField(
              decoration: InputDecoration(
                labelText: '商品検索',
                hintText: 'JAN コードまたは商品名を入力して選択',
                prefixIcon: const Icon(Icons.search),
                border: OutlineInputBorder(
                  borderRadius: BorderRadius.circular(12),
                ),
                filled: true,
              ),
            ),
          ),
          const SizedBox(height: 8),

          // 売上商品リスト（ダミーデータ用）
          Expanded(
            child: ListView(
              children: [
                Card(
                  margin: const EdgeInsets.symmetric(horizontal: 16, vertical: 4),
                  child: ExpansionTile(
                    title: Text(
                      '📦 売上商品',
                      style: TextStyle(fontWeight: FontWeight.bold),
                    ),
                    subtitle: const Text('商品を登録'),
                    children: [
                      ListView.builder(
                        shrinkWrap: true,
                        physics: const NeverScrollableScrollPhysics(),
                        itemCount: 0, // TODO: 実際のデータに差し替える
                        itemBuilder: (context, index) {
                          return Padding(
                            padding: const EdgeInsets.symmetric(vertical: 4),
                            child: Card(
                              child: ListTile(
                                leading: CircleAvatar(
                                  backgroundColor: Colors.orange.shade100,
                                  child: Icon(Icons.store, color: Colors.orange),
                                ),
                                title: Text('商品${index + 1}'),
                                subtitle: const Row(
                                  children: [
                                    SizedBox(width: 8),
                                    Icon(Icons.remove_circle_outline),
                                    SizedBox(width: 4),
                                    Text('数量：0 pcs / 単価：¥0'),
                                  ],
                                ),
                              ),
                            ),
                          );
                        },
                      ),
                    ],
                  ),
                ),
              ],
            ),
          ),

          const SizedBox(height: 16),
        ],
      ),
    );
  }

  /// 保存ダイアログ表示（TODO: DatabaseHelper.insertSales を呼び出す）
  void _showSaveDialog(BuildContext context) {
    showDialog(
      context: context,
      builder: (context) => AlertDialog(
        title: const Text('売上データを保存'),
        content: const Text(
          '入力した商品情報を販売アシストに保存します。\n\n DatabaseHelper.insertSales を呼び出す予定です。',
        ),
        actions: [
          TextButton(
            onPressed: () => Navigator.pop(context),
            child: const Text('キャンセル'),
          ),
          ElevatedButton(
            onPressed: () {
              // TODO: DatabaseHelper.insertSales(context) 呼び出し
              ScaffoldMessenger.of(context).showSnackBar(
                const SnackBar(
                  content: Text('売上データ保存処理中...'),
                  duration: Duration(seconds: 2),
                ),
              );
              Navigator.pop(context);
            },
            child: const Text('保存'),
          ),
        ],
      ),
    );
  }