// Version: 1.0.0
import 'package:flutter/material.dart';
import '../../models/customer.dart';
import '../../services/database_helper.dart';

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

  @override
  State<CustomerMasterScreen> createState() => _CustomerMasterScreenState();
}

class _CustomerMasterScreenState extends State<CustomerMasterScreen> {
  final DatabaseHelper _db = DatabaseHelper.instance;
  List<Customer> _customers = [];
  bool _isLoading = true;

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

  Future<void> _loadCustomers() async {
    try {
      final customers = await _db.getCustomers();
      setState(() {
        _customers = customers;
        _isLoading = false;
      });
    } catch (e) {
      if (!mounted) return;
      _showSnackBar(context, '顧客データを読み込みませんでした: $e');
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('得意先マスタ'),
        actions: [
          IconButton(icon: const Icon(Icons.refresh), onPressed: _loadCustomers,),
        ],
      ),
      body: _isLoading ? const Center(child: CircularProgressIndicator()) : _customers.isEmpty
        ? Center(
            child: Column(
              mainAxisAlignment: MainAxisAlignment.center,
              children: [
                Icon(Icons.inbox_outlined, size: 64, color: Colors.grey[300]),
                SizedBox(height: 16),
                Text('顧客データがありません', style: TextStyle(color: Colors.grey)),
                SizedBox(height: 16),
                IconButton(
                  icon: Icon(Icons.add, color: Theme.of(context).primaryColor),
                  onPressed: () => _showAddDialog(context),
                ),
              ],
            ),
          )
        : ListView.builder(
            padding: const EdgeInsets.all(8),
            itemCount: _customers.length,
            itemBuilder: (context, index) {
              final customer = _customers[index];
              return Dismissible(
                key: Key(customer.customerCode),
                direction: DismissDirection.endToStart,
                background: Container(
                  color: Colors.red,
                  alignment: Alignment.centerRight,
                  padding: const EdgeInsets.only(right: 20),
                  child: const Icon(Icons.delete, color: Colors.white),
                ),
                onDismissed: (_) => _deleteCustomer(customer.id!),
                child: Card(
                  margin: EdgeInsets.zero,
                  clipBehavior: Clip.antiAlias,
                  child: ListTile(
                    leading: CircleAvatar(
                      backgroundColor: Colors.blue.shade100,
                      child: const Icon(Icons.person, color: Colors.blue),
                    ),
                    title: Text(customer.name),
                    subtitle: Column(
                      crossAxisAlignment: CrossAxisAlignment.start,
                      children: [
                        if (customer.email != null)
                          Text('Email: ${customer.email}', style: const TextStyle(fontSize: 12)),
                        Text('税抜：${(customer.taxRate / 8 * 100).toStringAsFixed(1)}%'),
                        Text('割引：${customer.discountRate}%'),
                      ],
                    ),
                    trailing: Row(
                      mainAxisSize: MainAxisSize.min,
                      children: [
                        IconButton(icon: const Icon(Icons.edit), onPressed: () => _showEditDialog(context, customer),),
                        IconButton(icon: const Icon(Icons.more_vert), onPressed: () => _showMoreOptions(context, customer),),
                      ],
                    ),
                  ),
                ),
              );
            },
          ),
      floatingActionButton: FloatingActionButton.extended(
        icon: const Icon(Icons.add),
        label: const Text('新規登録'),
        onPressed: () => _showAddDialog(context),
      ),
    );
  }

  Future<void> _addCustomer(Customer customer) async {
    final db = await DatabaseHelper.instance.database;

    // 既存顧客リストを取得
    final existingCustomers = (await db.query('customers')) as List<Map<String, dynamic>>;
    final customerCodes = existingCustomers.map((e) => e['customer_code'] as String).toList();

    if (customerCodes.contains(customer.customerCode)) {
      _showSnackBar(context, '既に同じコードを持つ顧客が登録されています');
      return;
    }

    try {
      await db.insert('customers', customer.toMap());
      await DatabaseHelper.instance.saveSnapshot(customer); // Event sourcing snapshot
      await _loadCustomers();

      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          const SnackBar(content: Text('顧客を登録しました')),
        );
      }
    } catch (e) {
      _showSnackBar(context, '登録に失敗：$e');
    }
  }

  Future<void> _editCustomer(Customer customer) async {
    if (!mounted) return;
    ScaffoldMessenger.of(context).showSnackBar(
      SnackBar(
        content: Text('編集機能：${customer.name}'),
        action: const SnackBarAction(label: 'キャンセル', onPressed: () {}),
      ),
    );
  }

  Future<void> _deleteCustomer(int id) async {
    final confirmed = await showDialog<bool>(
      context: context,
      builder: (ctx) => AlertDialog(
        title: const Text('顧客削除'),
        content: Text('この顧客を削除しますか？履歴データも消去されます。'),
        actions: [
          TextButton(onPressed: () => Navigator.pop(ctx, false), child: const Text('キャンセル'),),
          ElevatedButton(
            onPressed: () => Navigator.pop(ctx, true),
            style: ElevatedButton.styleFrom(backgroundColor: Colors.red),
            child: const Text('削除'),
          ),
        ],
      ),
    );

    if (confirmed == true) {
      try {
        await DatabaseHelper.instance.delete(id);
        await _loadCustomers();
        if (mounted) {
          ScaffoldMessenger.of(context).showSnackBar(
            const SnackBar(content: Text('顧客を削除しました')),
          );
        }
      } catch (e) {
        _showSnackBar(context, '削除に失敗：$e');
      }
    }
  }

  void _showAddDialog(BuildContext context) {
    showDialog(
      context: context,
      builder: (ctx) => AlertDialog(
        title: const Text('新規顧客登録'),
        content: SingleChildScrollView(
          child: Column(
            mainAxisSize: MainAxisSize.min,
            children: [
              ListTile(
                title: const Text('得意先コード *'),
                subtitle: const Text('JAN 形式など（半角数字）'),
                onLongPress: () => _showSnackBar(context, '登録機能（プレースホルダ）'),
              ),
              ListTile(
                title: const Text('顧客名称 *'),
                subtitle: const Text('株式会社〇〇'),
                onLongPress: () => _showSnackBar(context, '登録機能（プレースホルダ）'),
              ),
              ListTile(
                title: const Text('電話番号'),
                subtitle: const Text('03-1234-5678'),
                onLongPress: () => _showSnackBar(context, '登録機能（プレースホルダ）'),
              ),
              ListTile(
                title: const Text('Email'),
                subtitle: const Text('example@example.com'),
                onLongPress: () => _showSnackBar(context, '登録機能（プレースホルダ）'),
              ),
              ListTile(
                title: const Text('住所'),
                subtitle: const Text('〒000-0000 市区町村名・番地'),
                onLongPress: () => _showSnackBar(context, '登録機能（プレースホルダ）'),
              ),
              const SizedBox(height: 12),
              Text(
                '※ 保存ボタンを押すと、上記の値から作成された顧客データが登録されます',
                textAlign: TextAlign.center,
                style: TextStyle(fontStyle: FontStyle.italic),
              ),
            ],
          ),
        ),
        actions: [
          TextButton(onPressed: () => Navigator.pop(ctx), child: const Text('キャンセル'),),
          ElevatedButton(
            onPressed: () {
              Navigator.pop(ctx);
              // 実際の登録処理は後期開発（プレースホルダ）
              _showSnackBar(context, '顧客データを保存します...');
            },
            child: const Text('保存'),
          ),
        ],
      ),
    );
  }

  void _showEditDialog(BuildContext context, Customer customer) {
    if (!mounted) return;
    showDialog(
      context: context,
      builder: (ctx) => AlertDialog(
        title: const Text('顧客編集'),
        content: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            ListTile(
              title: const Text('顧客コード'),
              subtitle: Text(customer.customerCode),
              onLongPress: () => _showSnackBar(context, '編集機能（プレースホルダ）'),
            ),
            ListTile(
              title: const Text('名称'),
              subtitle: Text(customer.name),
              onLongPress: () => _showSnackBar(context, '編集機能（プレースホルダ）'),
            ),
            ListTile(
              title: const Text('電話番号'),
              subtitle: Text(customer.phoneNumber),
              onLongPress: () => _showSnackBar(context, '編集機能（プレースホルダ）'),
            ),
            ListTile(
              title: const Text('税抜率'),
              subtitle: Text('${customer.taxRate}%'),
              onLongPress: () => _showSnackBar(context, '編集機能（プレースホルダ）'),
            ),
          ],
        ),
        actions: [
          TextButton(onPressed: () => Navigator.pop(ctx), child: const Text('キャンセル'),),
          ElevatedButton(
            onPressed: () {
              // 実際の保存処理は後期開発（プレースホルダ）
              _showSnackBar(context, '編集を保存します...');
              Navigator.pop(ctx);
            },
            child: const Text('保存'),
          ),
        ],
      ),
    );
  }

  void _showMoreOptions(BuildContext context, Customer customer) {
    showModalBottomSheet(
      context: context,
      builder: (ctx) => SafeArea(
        child: Padding(
          padding: const EdgeInsets.all(16),
          child: Column(
            mainAxisSize: MainAxisSize.min,
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              Text('『${customer.name}』のオプション機能', style: Theme.of(context).textTheme.titleLarge),
              ListTile(
                leading: const Icon(Icons.info_outline),
                title: const Text('顧客詳細表示'),
                onTap: () => _showCustomerDetail(context, customer),
              ),
              ListTile(
                leading: const Icon(Icons.history_edu),
                title: const Text('履歴表示（イベントソーシング）', style: TextStyle(color: Colors.grey)),
                onTap: () => _showSnackBar(context, 'イベント履歴機能は後期開発'),
              ),
              ListTile(
                leading: const Icon(Icons.copy),
                title: const Text('QR コード発行（未実装）', style: TextStyle(color: Colors.grey)),
                onTap: () => _showSnackBar(context, 'QR コード機能は後期開発で'),
              ),
            ],
          ),
        ),
      ),
    );
  }

  void _showCustomerDetail(BuildContext context, Customer customer) {
    if (!mounted) return;
    showDialog(
      context: context,
      builder: (ctx) => AlertDialog(
        title: const Text('顧客詳細'),
        content: SingleChildScrollView(
          child: Column(
            mainAxisSize: MainAxisSize.min,
            children: [
              _detailRow('得意先コード', customer.customerCode),
              _detailRow('名称', customer.name),
              _detailRow('電話番号', customer.phoneNumber),
              _detailRow('Email', customer.email ?? '-'),
              _detailRow('住所', customer.address),
              if (customer.salesPersonId > 0) _detailRow('担当者 ID', customer.salesPersonId.toString()),
              _detailRow('税抜率', '${customer.taxRate}%'),
              _detailRow('割引率', '${customer.discountRate}%'),
            ],
          ),
        ),
        actions: [
          TextButton(onPressed: () => Navigator.pop(ctx), child: const Text('閉じる'),),
        ],
      ),
    );
  }

  Widget _detailRow(String label, String value) {
    return Padding(
      padding: const EdgeInsets.only(bottom: 8),
      child: Row(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          SizedBox(width: 100),
          Expanded(child: Text(value)),
        ],
      ),
    );
  }

  Future<void> _showEventHistory(BuildContext context, Customer customer) async {
    if (!mounted) return;
    ScaffoldMessenger.of(context).showSnackBar(
      const SnackBar(content: Text('イベント履歴表示（未実装：後期開発）')),
    );
  }

  void _showSnackBar(BuildContext context, String message) {
    if (!mounted) return;
    ScaffoldMessenger.of(context).showSnackBar(
      SnackBar(
        content: Text(message),
      ),
    );
  }
}