import 'dart:io';

import 'package:flutter/foundation.dart';
import 'package:flutter/services.dart' show rootBundle;
import 'package:intl/intl.dart';
import 'package:path/path.dart' as p;
import 'package:path_provider/path_provider.dart';
import 'package:pdf/pdf.dart';
import 'package:pdf/widgets.dart' as pw;

import '../models/shipment_models.dart';
import 'company_repository.dart';

class ShippingLabelService {
  ShippingLabelService({CompanyRepository? companyRepository})
      : _companyRepository = companyRepository ?? CompanyRepository();

  final CompanyRepository _companyRepository;

  Future<String?> generateLabel(Shipment shipment) async {
    try {
      final company = await _companyRepository.getCompanyInfo();
      final fontData = await rootBundle.load('assets/fonts/ipaexg.ttf');
      final ipaex = pw.Font.ttf(fontData);
      final dateFormat = DateFormat('yyyy/MM/dd');

      final pdf = pw.Document();
      pdf.addPage(
        pw.Page(
          pageFormat: PdfPageFormat.a5,
          margin: const pw.EdgeInsets.all(20),
          build: (context) {
            return pw.Column(
              crossAxisAlignment: pw.CrossAxisAlignment.start,
              children: [
                pw.Text('出荷ラベル', style: pw.TextStyle(fontSize: 20, fontWeight: pw.FontWeight.bold, font: ipaex)),
                pw.SizedBox(height: 8),
                pw.Text('発行日: ${dateFormat.format(DateTime.now())}', style: pw.TextStyle(font: ipaex)),
                pw.Divider(),
                pw.Text('差出人', style: pw.TextStyle(fontWeight: pw.FontWeight.bold, font: ipaex)),
                pw.Text(company.name, style: pw.TextStyle(font: ipaex)),
                if (company.address != null) pw.Text(company.address!, style: pw.TextStyle(font: ipaex)),
                if (company.tel != null) pw.Text('TEL: ${company.tel}', style: pw.TextStyle(font: ipaex)),
                pw.SizedBox(height: 12),
                pw.Text('宛先', style: pw.TextStyle(fontWeight: pw.FontWeight.bold, font: ipaex)),
                pw.Text(shipment.customerNameSnapshot ?? '取引先未設定', style: pw.TextStyle(fontSize: 16, font: ipaex)),
                if (shipment.orderNumberSnapshot != null)
                  pw.Text('受注番号: ${shipment.orderNumberSnapshot}', style: pw.TextStyle(font: ipaex)),
                pw.SizedBox(height: 12),
                pw.Text('配送情報', style: pw.TextStyle(fontWeight: pw.FontWeight.bold, font: ipaex)),
                pw.Text('配送業者: ${shipment.carrierName ?? '-'}', style: pw.TextStyle(font: ipaex)),
                pw.Text('追跡番号: ${shipment.trackingNumber ?? '-'}', style: pw.TextStyle(font: ipaex)),
                if (shipment.trackingUrl != null && shipment.trackingUrl!.isNotEmpty)
                  pw.Text('追跡URL: ${shipment.trackingUrl}', style: pw.TextStyle(font: ipaex)),
                pw.SizedBox(height: 12),
                pw.Text('出荷明細', style: pw.TextStyle(fontWeight: pw.FontWeight.bold, font: ipaex)),
                pw.SizedBox(height: 6),
                if (shipment.items.isEmpty)
                  pw.Text('明細登録なし', style: pw.TextStyle(font: ipaex))
                else
                  pw.TableHelper.fromTextArray(
                    headers: const ['品目', '数量'],
                    data: shipment.items
                        .map(
                          (item) => [
                            item.description,
                            item.quantity.toString(),
                          ],
                        )
                        .toList(),
                    headerStyle: pw.TextStyle(fontWeight: pw.FontWeight.bold, font: ipaex),
                    cellStyle: pw.TextStyle(font: ipaex),
                    columnWidths: const {
                      0: pw.FlexColumnWidth(3),
                      1: pw.FlexColumnWidth(1),
                    },
                  ),
                if (shipment.notes?.isNotEmpty == true) ...[
                  pw.SizedBox(height: 12),
                  pw.Text('備考', style: pw.TextStyle(fontWeight: pw.FontWeight.bold, font: ipaex)),
                  pw.Text(shipment.notes!, style: pw.TextStyle(font: ipaex)),
                ],
              ],
            );
          },
        ),
      );

      final directory = await getApplicationDocumentsDirectory();
      final timestamp = DateFormat('yyyyMMdd_HHmmss').format(DateTime.now());
      final orderFragment = shipment.orderNumberSnapshot ?? shipment.id.substring(0, 6);
      final fileName = 'shipping_label_${orderFragment}_$timestamp.pdf';
      final file = File(p.join(directory.path, fileName));
      await file.writeAsBytes(await pdf.save());
      return file.path;
    } catch (e) {
      debugPrint('Shipping label generation failed: $e');
      return null;
    }
  }
}