import 'dart:math';
import 'package:crypto/crypto.dart';
import 'dart:convert';

class CommonUtil {
  static String generateMd5(String input) {
    List<int> bytes = utf8.encode(input); // 将字符串转换为字节码
    Digest md5Hash = md5.convert(bytes); // 对字节码进行MD5加密
    String encryptedString = md5Hash.toString(); // 获取加密后的字符串
    return encryptedString;
  }

  static String generateTicketNumber() {
    Random random = Random();

    int randomTwoDigitNumber = random.nextInt(99);
    String twoDigitNumber = randomTwoDigitNumber.toString().padLeft(2, '0');

    // 格式化数字串
    String formattedNumber =
        '${random.nextInt(9999999).toString().padLeft(7, '0')}${random.nextInt(9999999).toString().padLeft(7, '0')}-$twoDigitNumber';

    return formattedNumber;
  }

  static String firstUppercase(String text) {
    return '${text[0].toUpperCase()}${text.substring(1)}';
  }

  static List<T> flattenTree<T extends TreeNode>(List<T> children) {
    List<T> result = children;
    for (T child in children) {
      if (child.children != null) {
        result.addAll(flattenTree(child.children as List<T>));
      }
    }
    return result;
  }
}

class TreeNode<T> {
  List<T>? children;
}