// version: 1.0.2 (Japanese Support & SHA-256 Edition)
import 'dart:io';
import 'dart:typed_data';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart' show rootBundle;
import 'package:pdf/widgets.dart' as pw;
import 'package:path_provider/path_provider.dart';
import 'package:crypto/crypto.dart';
import 'package:intl/intl.dart';

void main() => runApp(const MaterialApp(home: InvoiceApp()));

class InvoiceApp extends StatefulWidget {
  const InvoiceApp({super.key});
  @override
  State<InvoiceApp> createState() => _InvoiceAppState();
}

class _InvoiceAppState extends State<InvoiceApp> {
  final _clientController = TextEditingController(text: "現場太郎 様");
  final _amountController = TextEditingController(text: "1500");
  String _status = "フォントを配置してPDFを発行してください";

  Future<void> _generateInvoice() async {
    final pdf = pw.Document();

    // 1. 日本語フォントの読み込み (assets/fonts/ に配置済み前提)
    // もしまだ配置してなければ、この3行をコメントアウトしてください
    final fontData = await rootBundle.load("assets/fonts/ipaexg.ttf");
    final ttf = pw.Font.ttf(fontData);
    final myTheme = pw.ThemeData.withFont(base: ttf, bold: ttf);

    final clientName = _clientController.text;
    final int unitPrice = int.tryParse(_amountController.text) ?? 0;
    final int tax = (unitPrice * 0.1).floor();
    final int total = unitPrice + tax;
    final dateStr = DateFormat('yyyy/MM/dd HH:mm').format(DateTime.now());

    // PDFドキュメントの作成
    pdf.addPage(
      pw.Page(
        theme: myTheme, // 日本語テーマ適用
        build: (context) => pw.Column(
          crossAxisAlignment:
              pw.CrossAxisAlignment.start, // 'cross' を 'crossAxisAlignment' に修正
          children: [
            pw.Text("請求書 (Invoice)", style: pw.TextStyle(fontSize: 30)),
            pw.Divider(),
            pw.Text("宛名: $clientName"),
            pw.Text("日付: $dateStr"),
            pw.SizedBox(height: 20),
            pw.Text("単価（税抜）: $unitPrice 円"),
            pw.Text("消費税 (10%): $tax 円"),
            pw.Text(
              "合計金額（税込）: $total 円",
              style: pw.TextStyle(fontWeight: pw.FontWeight.bold, fontSize: 20),
            ),
            pw.SizedBox(height: 40),
            pw.Text("※本書類はシステムにより自動生成され、改ざん防止ハッシュが付与されています。"),
          ],
        ),
      ),
    );

    final Uint8List bytes = await pdf.save();

    // 2. SHA-256ハッシュ計算
    final hash = sha256.convert(bytes).toString().substring(0, 10);
    final fileName =
        "${DateFormat('yyyyMMdd').format(DateTime.now())}_${total}円_hash_$hash.pdf";

    // 3. 保存
    final directory = await getExternalStorageDirectory();
    final file = File("${directory!.path}/$fileName");
    await file.writeAsBytes(bytes);

    setState(() {
      _status = "【発行成功】\nファイル: $fileName\nハッシュ: $hash";
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text("現場のじぇみエモン請求書 V1.0")),
      body: Padding(
        padding: const EdgeInsets.all(16.0),
        child: Column(
          children: [
            TextField(
              controller: _clientController,
              decoration: const InputDecoration(labelText: "取引先名"),
            ),
            TextField(
              controller: _amountController,
              decoration: const InputDecoration(labelText: "単価(10%抜き)"),
            ),
            const SizedBox(height: 20),
            ElevatedButton(
              onPressed: _generateInvoice,
              style: ElevatedButton.styleFrom(
                minimumSize: const Size(double.infinity, 50),
              ),
              child: const Text("日本語PDF発行（ハッシュ付与）"),
            ),
            const SizedBox(height: 20),
            SelectableText(
              _status,
              style: const TextStyle(
                color: Colors.blue,
                fontWeight: FontWeight.bold,
              ),
            ),
          ],
        ),
      ),
    );
  }
}