// Version: 3.0 - シンプル得意先マスタ画面（簡素版）
// ※ MasterEditDialog を使用するため、独自の実装は不要です

import 'package:flutter/material.dart';
import '../../models/customer.dart';
import '../../services/database_helper.dart';
import 'master_edit_dialog.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();
      if (mounted) setState(() {
        _customers = customers ?? const <Customer>[];
        _isLoading = false;
      });
    } catch (e) {
      if (!mounted) return;
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(content: Text('顧客データを読み込みませんでした：$e'), backgroundColor: Colors.red),
      );
    }
  }

  Future<void> _addCustomer() async {
    final customer = await showDialog<Customer>(
      context: context,
      builder: (ctx) => MasterEditDialog(
        title: '新規得意先登録',
        onSave: (data) async {
          if (mounted) {
            setState(() => _customers.insert(0, data));
            await _db.insertCustomer(data);
            ScaffoldMessenger.of(context).showSnackBar(
              const SnackBar(content: Text('顧客を登録しました'), backgroundColor: Colors.green),
            );
            _loadCustomers();
          }
          return true;
        },
      ),
    );

    if (customer != null) _loadCustomers();
  }

  Future<void> _editCustomer(Customer customer) async {
    final updated = await showDialog<Customer>(
      context: context,
      builder: (ctx) => MasterEditDialog(
        title: '得意先編集',
        initialData: customer,
        showStatusFields: true,
        onSave: (data) async {
          if (mounted) {
            await _db.updateCustomer(data);
            ScaffoldMessenger.of(context).showSnackBar(
              const SnackBar(content: Text('顧客を更新しました'), backgroundColor: Colors.green),
            );
            _loadCustomers();
          }
          return true;
        },
      ),
    );

    if (updated != null) _loadCustomers();
  }

  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 _db.deleteCustomer(id);
        ScaffoldMessenger.of(context).showSnackBar(
          const SnackBar(content: Text('顧客を削除しました'), backgroundColor: Colors.green),
        );
        _loadCustomers();
      } catch (e) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(content: Text('削除に失敗：$e'), backgroundColor: Colors.red),
        );
      }
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('/M2. 得意先マスタ')),
      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('得意先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: _addCustomer,
                  ),
                ],
              ),
            )
          : ListView.builder(
              padding: const EdgeInsets.all(8),
              itemCount: _customers.length,
              itemBuilder: (context, index) {
                final customer = _customers[index];
                return Card(
                  margin: const EdgeInsets.only(bottom: 8),
                  elevation: 4,
                  child: ListTile(
                    leading: CircleAvatar(backgroundColor: Colors.blue.shade100, child: const Icon(Icons.person, color: Colors.blue)),
                    title: Text(customer.name ?? '未入力'),
                    subtitle: Column(
                      crossAxisAlignment: CrossAxisAlignment.start,
                      children: [
                        if (customer.email.isNotEmpty) Text('Email: ${customer.email}', style: const TextStyle(fontSize: 12)),
                        Text('登録日：${DateFormat('yyyy/MM/dd').format(customer.createdAt ?? DateTime.now())}'),
                      ],
                    ),
                    trailing: Row(
                      mainAxisSize: MainAxisSize.min,
                      children: [
                        IconButton(icon: const Icon(Icons.edit), onPressed: () => _editCustomer(customer)),
                        PopupMenuButton<String>(
                          onSelected: (value) => value == 'delete' ? _deleteCustomer(customer.id ?? 0) : null,
                          itemBuilder: (ctx) => [
                            PopupMenuItem(child: const Text('詳細'), onPressed: () => _showDetail(context, customer)),
                            PopupMenuItem(child: const Text('削除'), onPressed: () => _deleteCustomer(customer.id ?? 0)),
                          ],
                        ),
                      ],
                    ),
                  ),
                );
              },
            ),
      floatingActionButton: FloatingActionButton.extended(
        icon: const Icon(Icons.add),
        label: const Text('新規登録'),
        onPressed: _addCustomer,
      ),
    );
  }

  Future<void> _showDetail(BuildContext context, Customer customer) async {
    showDialog(
      context: context,
      builder: (ctx) => AlertDialog(
        title: const Text('顧客詳細'),
        content: SingleChildScrollView(
          child: Column(
            mainAxisSize: MainAxisSize.min,
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              _detailRow('得意先コード', customer.customerCode ?? '-'),
              _detailRow('名称', customer.name ?? '-'),
              _detailRow('Email', customer.email.isNotEmpty ? customer.email : '-'),
              _detailRow('登録日', DateFormat('yyyy/MM/dd').format(customer.createdAt)),
            ],
          ),
        ),
        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: 12),
      child: Row(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          SizedBox(width: 80),
          Expanded(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Text(label, style: TextStyle(fontWeight: FontWeight.bold)),
                if (value != '-') Text(value),
              ],
            ),
          ),
        ],
      ),
    );
  }

  Future<void> _onCopyFromOtherMaster() async {
    final selected = await showDialog<String?>(
      context: context,
      builder: (ctx) => AlertDialog(
        title: const Text('他のマスタからコピー'),
        content: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            ListTile(leading: Icon(Icons.store, color: Colors.blue), title: const Text('仕入先マスタから'), onTap: () => Navigator.pop(ctx, 'supplier')),
            ListTile(leading: Icon(Icons.inventory_2, color: Colors.orange), title: const Text('商品マスタから'), onTap: () => Navigator.pop(ctx, 'product')),
          ],
        ),
        actions: [
          TextButton(onPressed: () => Navigator.pop(ctx), child: const Text('キャンセル')),
        ],
      ),
    );

    if (selected != null && mounted) {
      ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Text('コピー機能は後期開発：$selected')));
    }
  }
}