import 'package:flutter/material.dart';
import 'package:intl/intl.dart';
import '../models/invoice_models.dart';
import '../services/invoice_repository.dart';
import 'invoice_detail_page.dart';

/// 帳票（見積・納品・請求・領収）の履歴一覧を表示・管理する画面
class InvoiceHistoryScreen extends StatefulWidget {
  const InvoiceHistoryScreen({Key? key}) : super(key: key);

  @override
  State<InvoiceHistoryScreen> createState() => _InvoiceHistoryScreenState();
}

class _InvoiceHistoryScreenState extends State<InvoiceHistoryScreen> {
  final InvoiceRepository _repository = InvoiceRepository();
  List<Invoice> _invoices = [];
  bool _isLoading = true;

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

  /// DBから履歴を読み込む
  Future<void> _loadInvoices() async {
    setState(() => _isLoading = true);
    final data = await _repository.getAllInvoices();
    setState(() {
      _invoices = data;
      _isLoading = false;
    });
  }

  /// 不要な（DBに紐付かない）PDFファイルを一括削除
  Future<void> _cleanupFiles() async {
    final count = await _repository.cleanupOrphanedPdfs();
    if (mounted) {
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(content: Text('$count 個の不要なPDFファイルを削除しました')),
      );
    }
  }

  /// 履歴から個別に削除
  Future<void> _deleteInvoice(Invoice invoice) async {
    final confirmed = await showDialog<bool>(
      context: context,
      builder: (context) => AlertDialog(
        title: const Text("削除の確認"),
        content: Text("${invoice.type.label}番号: ${invoice.invoiceNumber}\nこのデータを削除しますか？\n(実体PDFファイルも削除されます)"),
        actions: [
          TextButton(onPressed: () => Navigator.pop(context, false), child: const Text("キャンセル")),
          TextButton(
            onPressed: () => Navigator.pop(context, true),
            child: const Text("削除する", style: TextStyle(color: Colors.red)),
          ),
        ],
      ),
    );

    if (confirmed == true) {
      await _repository.deleteInvoice(invoice);
      _loadInvoices();
    }
  }

  @override
  Widget build(BuildContext context) {
    final amountFormatter = NumberFormat("#,###");
    final dateFormatter = DateFormat('yyyy/MM/dd HH:mm');

    return Scaffold(
      appBar: AppBar(
        title: const Text("発行履歴管理"),
        backgroundColor: Colors.blueGrey,
        foregroundColor: Colors.white,
        actions: [
          IconButton(
            icon: const Icon(Icons.cleaning_services),
            tooltip: "ゴミファイルを掃除",
            onPressed: _cleanupFiles,
          ),
          IconButton(
            icon: const Icon(Icons.refresh),
            onPressed: _loadInvoices,
          ),
        ],
      ),
      body: _isLoading
          ? const Center(child: CircularProgressIndicator())
          : _invoices.isEmpty
              ? Center(
                  child: Column(
                    mainAxisAlignment: MainAxisAlignment.center,
                    children: [
                      Icon(Icons.history, size: 64, color: Colors.grey.shade300),
                      const SizedBox(height: 16),
                      const Text("発行済みの帳票はありません", style: TextStyle(color: Colors.grey)),
                    ],
                  ),
                )
              : ListView.builder(
                  itemCount: _invoices.length,
                  itemBuilder: (context, index) {
                    final invoice = _invoices[index];
                    return Card(
                      margin: const EdgeInsets.symmetric(horizontal: 12, vertical: 6),
                      child: ListTile(
                        leading: Stack(
                          alignment: Alignment.bottomRight,
                          children: [
                            const CircleAvatar(
                              backgroundColor: Colors.indigo,
                              child: Icon(Icons.description, color: Colors.white),
                            ),
                            if (invoice.isShared)
                              Container(
                                decoration: const BoxDecoration(
                                  color: Colors.white,
                                  shape: BoxShape.circle,
                                ),
                                child: const Icon(
                                  Icons.check_circle,
                                  color: Colors.green,
                                  size: 18,
                                ),
                              ),
                          ],
                        ),
                        title: Row(
                          children: [
                            Container(
                              padding: const EdgeInsets.symmetric(horizontal: 6, vertical: 2),
                              decoration: BoxDecoration(
                                color: Colors.blueGrey.shade100,
                                borderRadius: BorderRadius.circular(4),
                              ),
                              child: Text(
                                invoice.type.label,
                                style: const TextStyle(fontSize: 10, fontWeight: FontWeight.bold),
                              ),
                            ),
                            const SizedBox(width: 8),
                            Expanded(
                              child: Text(
                                invoice.customer.formalName,
                                style: const TextStyle(fontWeight: FontWeight.bold),
                                overflow: TextOverflow.ellipsis,
                              ),
                            ),
                          ],
                        ),
                        subtitle: Column(
                          crossAxisAlignment: CrossAxisAlignment.start,
                          children: [
                            Text("No: ${invoice.invoiceNumber}"),
                            Text(dateFormatter.format(invoice.date), style: const TextStyle(fontSize: 12)),
                          ],
                        ),
                        trailing: Text(
                          "¥${amountFormatter.format(invoice.totalAmount)}",
                          style: const TextStyle(
                            fontWeight: FontWeight.bold,
                            color: Colors.indigo,
                            fontSize: 16,
                          ),
                        ),
                        onTap: () async {
                          await Navigator.push(
                            context,
                            MaterialPageRoute(
                              builder: (context) => InvoiceDetailPage(invoice: invoice),
                            ),
                          );
                          _loadInvoices();
                        },
                        onLongPress: () => _deleteInvoice(invoice),
                      ),
                    );
                  },
                ),
    );
  }
}