using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Common.Utils
{
    public static class RandomHelper
    {
        //
        //
        //   length:
        public static string RandomNumbers(int length = 4)
        {
            if (length <= 4)
            {
                length = 4;
            }

            if (length >= 8)
            {
                length = 8;
            }

            string value = 1.ToString().PadRight(length, '0');
            string value2 = 1.ToString().PadRight(length + 1, '0');
            return Random.Shared.Next(Convert.ToInt32(value), Convert.ToInt32(value2)).ToString();
        }

        //
        //
        //   length:
        public static string RandomChars(int length = 4)
        {
            if (length <= 4)
            {
                length = 4;
            }

            if (length >= 8)
            {
                length = 8;
            }

            char[] array = new char[62]
            {
            '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
            'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J',
            'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T',
            'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd',
            'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',
            'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x',
            'y', 'z'
            };
            string text = "";
            for (int i = 0; i < length; i++)
            {
                int num = Random.Shared.Next(0, 61);
                text += array[num];
            }

            return text;
        }

        //
        //
        //   length:
        public static string RandomNoRepeatNumber(int length)
        {
            int num = 0;
            string text = string.Empty;
            long num2 = DateTime.Now.Ticks + num;
            num++;
            Random random = new Random((int)(num2 & 0xFFFFFFFFu) | (int)(num2 >> num));
            for (int i = 0; i < length; i++)
            {
                int num3 = random.Next();
                text += (char)(48 + (ushort)(num3 % 10));
            }

            return text;
        }

        //
        //
        //   length:
        public static string RandomNoRepeatChars(int length)
        {
            int num = 0;
            string text = string.Empty;
            long num2 = DateTime.Now.Ticks + num;
            num++;
            Random random = new Random((int)(num2 & 0xFFFFFFFFu) | (int)(num2 >> num));
            for (int i = 0; i < length; i++)
            {
                int num3 = random.Next();
                text += ((num3 % 2 != 0) ? ((char)(65 + (ushort)(num3 % 26))) : ((char)(48 + (ushort)(num3 % 10))));
            }

            return text;
        }

        //
        //
        //   allChar:
        //
        //   length:
        public static string GetRandomCode(string allChar, int length)
        {
            string[] array = allChar.Split(',');
            string text = "";
            int num = -1;
            for (int i = 0; i < length; i++)
            {
                int num2 = Random.Shared.Next(array.Length - 1);
                while (num == num2)
                {
                    num2 = Random.Shared.Next(array.Length - 1);
                }

                num = num2;
                text += array[num2];
            }

            return text;
        }

       

    }
}