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

namespace New_College.Common
{
    public class YZYSignCrypt
    {
        public static string GetCryptCode(DateTime dt)
        {
            string datestring = dt.ToString("yyyy-MM-dd HH:mm:ss");
            StringBuilder sb = new StringBuilder();
            var rnd = new Random();
            int k = rnd.Next(0, 18);
            for (int i = 0; i < datestring.Length; i++)
            {
                if (k == i)
                {
                    sb.Append("A");
                }
                switch (datestring[i])
                {
                    case '0':
                        sb.Append("Z");
                        break;
                    case '1':
                        sb.Append("0");
                        break;
                    case '2':
                        sb.Append("T");
                        break;
                    case '3':
                        sb.Append("t");
                        break;
                    case '4':
                        sb.Append("F");
                        break;
                    case '5':
                        sb.Append("f");
                        break;
                    case '6':
                        sb.Append("S");
                        break;
                    case '7':
                        sb.Append("s");
                        break;
                    case '8':
                        sb.Append("E");
                        break;
                    case '9':
                        sb.Append("N");
                        break;
                    case '-':
                        sb.Append("L");
                        break;
                    case ':':
                        sb.Append("D");
                        break;
                    case ' ':
                        sb.Append("a");
                        break;
                }
            }
            return sb.ToString();
        }

    }
}