mail-hub/test/mime_parser_test.dart

import 'dart:convert';

import 'package:flutter_test/flutter_test.dart';
import 'package:mail_hub/core/models/address.dart';
import 'package:mail_hub/core/protocol/mime/mime_builder.dart';
import 'package:mail_hub/core/protocol/mime/mime_codec.dart';
import 'package:mail_hub/core/protocol/mime/mime_parser.dart';

void main() {
  group('MIME 解析', () {
    test('解析基本头 + 主题 RFC2047', () {
      final raw = [
        'Subject: =?UTF-8?B?5L2g55qE6YKu5Lu2?=',
        'From: "张三" <zhangsan@example.com>',
        'To: lisi@example.com, "Wang Wu" <wangwu@example.com>',
        'Date: Tue, 18 Aug 2026 08:30:00 +0800',
        'Content-Type: text/plain; charset="utf-8"',
        'Message-ID: <abc123@example.com>',
        '',
        '你好世界！',
      ].join('\r\n');
      final parsed = MimeParser.parse(ascii(raw));
      expect(parsed.subject, '你的邮件');
      expect(parsed.from!.name, '张三');
      expect(parsed.from!.email, 'zhangsan@example.com');
      expect(parsed.to.length, 2);
      expect(parsed.to[1].name, 'Wang Wu');
      expect(parsed.textBody, '你好世界！');
      expect(parsed.date!.year, 2026);
    });

    test('multipart/alternative 取 HTML 与纯文本', () {
      final boundary = '----=_test_1234567890abcdef';
      final raw = [
        'Subject: test',
        'Content-Type: multipart/alternative; boundary="$boundary"',
        '',
        '--$boundary',
        'Content-Type: text/plain; charset="utf-8"',
        'Content-Transfer-Encoding: base64',
        '',
        base64.encode(utf8.encode('纯文本内容')),
        '--$boundary',
        'Content-Type: text/html; charset="utf-8"',
        'Content-Transfer-Encoding: quoted-printable',
        '',
        '<b>=E7=BA=AF=E6=96=87=E6=9C=AC</b>',
        '--$boundary--',
        '',
      ].join('\r\n');
      final parsed = MimeParser.parse(ascii(raw));
      expect(parsed.textBody, '纯文本内容');
      expect(parsed.htmlBody, '<b>纯文本</b>');
    });

    test('multipart/mixed 带附件', () {
      final boundary = '----=_test_mixed_1234567890abcdef';
      final raw = [
        'Subject: with attachment',
        'Content-Type: multipart/mixed; boundary="$boundary"',
        '',
        '--$boundary',
        'Content-Type: text/plain; charset="utf-8"',
        '',
        '正文',
        '--$boundary',
        'Content-Type: application/pdf; name="=?UTF-8?B?5oql5ZGK5paH5Lu2LnBkZg==?="',
        'Content-Transfer-Encoding: base64',
        'Content-Disposition: attachment; filename="=?UTF-8?B?5oql5ZGK5paH5Lu2LnBkZg==?="',
        '',
        'JVBERi0xLjQ=',
        '--$boundary--',
        '',
      ].join('\r\n');
      final parsed = MimeParser.parse(ascii(raw));
      expect(parsed.textBody, '正文');
      expect(parsed.attachments.length, 1);
      expect(parsed.attachments[0].fileName, '报告文件.pdf');
      expect(parsed.attachments[0].contentType, 'application/pdf');
      expect(parsed.attachments[0].size, greaterThan(0));
    });

    test('GBK 编码中文邮件', () {
      // GBK: 测试 = B2 E2 CA D4 ; 主题 "测试" base64 = suLK1A==
      final raw = 'Subject: =?GBK?B?suLK1A==?=\r\n'
          'Content-Type: text/plain; charset="gbk"\r\n\r\n';
      final body = <int>[0xB2, 0xE2, 0xCA, 0xD4]; // 测试 (GBK)
      final parsed = MimeParser.parse([...ascii(raw), ...body]);
      expect(parsed.subject, '测试');
      expect(parsed.textBody, '测试');
    });

    test('内嵌图片 CID', () {
      final boundary = '----=_test_cid_1234567890abcdef';
      final raw = [
        'Subject: inline',
        'Content-Type: multipart/related; boundary="$boundary"',
        '',
        '--$boundary',
        'Content-Type: text/html; charset="utf-8"',
        '',
        '<img src="cid:img1@example.com">',
        '--$boundary',
        'Content-Type: image/png',
        'Content-Transfer-Encoding: base64',
        'Content-ID: <img1@example.com>',
        'Content-Disposition: inline',
        '',
        'iVBORw0KGgo=',
        '--$boundary--',
        '',
      ].join('\r\n');
      final parsed = MimeParser.parse(ascii(raw));
      expect(parsed.htmlBody, contains('cid:img1@example.com'));
      expect(parsed.inlineImages.containsKey('img1@example.com'), true);
      expect(parsed.inlineImages['img1@example.com']!.length, 8);
    });

    test('RFC2231 文件名', () {
      final raw = [
        'Content-Type: application/octet-stream; name*=UTF-8\'\'%E6%B5%8B%E8%AF%95.txt',
        'Content-Disposition: attachment; filename*=UTF-8\'\'%E6%B5%8B%E8%AF%95.txt',
        '',
        'data',
      ].join('\r\n');
      final parsed = MimeParser.parse(ascii(raw));
      expect(parsed.attachments.length, 1);
      expect(parsed.attachments[0].fileName, '测试.txt');
    });
  });

  group('编码解码', () {
    test('RFC2047 编码词解码', () {
      expect(CharsetDecoder.decodeEncodedWords('=?UTF-8?B?5L2g5aW9?='), '你好');
      expect(CharsetDecoder.decodeEncodedWords('=?utf-8?q?hello=20world?='),
          'hello world');
      expect(CharsetDecoder.decodeEncodedWords('plain text'), 'plain text');
      expect(
          CharsetDecoder.decodeEncodedWords(
              '=?UTF-8?B?5L2g5aW9?= =?UTF-8?B?5LiW55WM?='),
          '你好世界');
    });

    test('Quoted-Printable 解码', () {
      final decoded = TransferDecoder.decode(
          ascii('a=20b=0D=0Ac=E4=B8=AD'), 'quoted-printable');
      expect(latin1.decode(decoded), contains('a b'));
      expect(utf8.decode(decoded), contains('中'));
    });
  });

  group('MimeBuilder 往返', () {
    test('构建 + 解析 multipart/alternative', () {
      final raw = MimeBuilder.build(
        from: const MailAddress('张三', 'zhangsan@example.com'),
        to: const [MailAddress('李四', 'lisi@example.com')],
        subject: '测试主题',
        textBody: '纯文本部分',
        htmlBody: '<b>HTML部分</b>',
      );
      final parsed = MimeParser.parse(raw);
      expect(parsed.subject, '测试主题');
      expect(parsed.textBody, '纯文本部分');
      expect(parsed.htmlBody, contains('HTML部分'));
    });

    test('构建 + 解析带附件邮件', () {
      final raw = MimeBuilder.build(
        from: const MailAddress('张三', 'zhangsan@example.com'),
        to: const [MailAddress('李四', 'lisi@example.com')],
        subject: '附件邮件',
        textBody: '请查收附件',
        attachments: [
          (
            name: '数据.txt',
            bytes: utf8.encode('hello 附件'),
            contentType: 'text/plain',
          ),
        ],
      );
      final parsed = MimeParser.parse(raw);
      expect(parsed.textBody, '请查收附件');
      expect(parsed.attachments.length, 1);
      expect(parsed.attachments[0].fileName, '数据.txt');
      expect(utf8.decode(parsed.attachments[0].data!.bytes), 'hello 附件');
    });
  });
}

// ---- 测试辅助 ----
// 真实邮件原始字节通常为 ASCII（中文走编码词/base64），
// 但为方便测试直接用 UTF-8 编码原始串
List<int> ascii(String s) => utf8.encode(s);