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

namespace StressClient
{
    class Helper
    {
        // 字符串转16进制字符串   AB-->4142
        public static string StrToHexStr(string src, Encoding encode)
        {
            byte[] b = encode.GetBytes(src);

            string result = string.Empty;
            foreach (var t in b)
            {
	            result += Convert.ToString(t, 16);
            }
            return result;
        }

        // 将16进制字符串转换到byte[]
        public static byte[] HexStrToArrary(string src)
        {
            int count = src.Length / 2;
            byte[] b = new byte[count];
            for (int i = 0; i < count; i++)
            {
                string val = "0x" + src.Substring(i * 2, 2);
                b[i] = Convert.ToByte(val, 16);    // '0x41'->65
            }
            return b;
        }

        public static string do_CRC(byte[] data)
        {
            byte check = 0;
            uint crc = 0xFFFF;

            for (int idx = 0; idx < data.Length; idx++)
            {
                byte pos = data[idx];
                crc = (crc >> 8) ^ pos;
                for (int i = 0; i < 8; i++)
                {
                    check = (byte)(crc & 0x0001);
                    crc >>= 1;
                    if (check == 0x0001)
                        crc ^= 0xA001;
                }
            }

            //string ret_str = Convert.ToString(crc, 16);
            string ret_str = crc.ToString("X4"); ;
            return ret_str.ToUpper();
        }

        public static string do_CRC16(byte[] data)
        {
            byte[] returnVal = new byte[2];
            byte CRC16Lo, CRC16Hi, CL, CH, SaveHi, SaveLo;
            int i, Flag;
            CRC16Lo = 0xFF;
            CRC16Hi = 0xFF;
            CL = 0x86;
            CH = 0x68;
            for (i = 0; i < data.Length; i++)
            {
                CRC16Lo = (byte)(CRC16Lo ^ data[i]);//每一个数据与CRC寄存器进行异或
                for (Flag = 0; Flag <= 7; Flag++)
                {
                    SaveHi = CRC16Hi;
                    SaveLo = CRC16Lo;
                    CRC16Hi = (byte)(CRC16Hi >> 1);//高位右移一位
                    CRC16Lo = (byte)(CRC16Lo >> 1);//低位右移一位
                    if ((SaveHi & 0x01) == 0x01)//如果高位字节最后一位为
                    {
                        CRC16Lo = (byte)(CRC16Lo | 0x80);//则低位字节右移后前面补 否则自动补0
                    }
                    if ((SaveLo & 0x01) == 0x01)//如果LSB为1，则与多项式码进行异或
                    {
                        CRC16Hi = (byte)(CRC16Hi ^ CH);
                        CRC16Lo = (byte)(CRC16Lo ^ CL);
                    }
                }
            }
            returnVal[0] = CRC16Hi;//CRC高位
            returnVal[1] = CRC16Lo;//CRC低位
            return Encoding.UTF8.GetString(returnVal);
        }

        private static float GenRandom(int minVal, int maxVal)
        {
            Random rdm = new Random();
            int val = rdm.Next(minVal, maxVal);
            return (float)(val / 100.0);
            
        }

        public static string MakeReqStr1(string MN_id, DateTime curTime)
        {
            // 时间戳QN , 格式YYYYMMDDhhmmsszzz            
            string ts_str = curTime.ToString("yyyyMMddHHmmssffff");
            string QN_val = ts_str.Substring(0, 14);

            // 分钟填5的倍数，秒填00
            int minute = curTime.Minute - curTime.Minute % 5;
            Object[] param = new Object[] { curTime.Year, curTime.Month, curTime.Day, curTime.Hour, minute, 0 };
            string cur_dt = string.Format("{0:D4}{1:D2}{2:D2}{3:D2}{4:D2}{5:D2}", param);

            // 其他各参数
            string ST_val = "80";
            string CN_val = "2011";
            string PW_val = "123456";
            string Flag_val = "5";
            string DateTime_val = cur_dt;
            float S20006_Rtd = GenRandom(200, 500);
            float S30004_Rtd = GenRandom(3, 9);
            float S30005_Rtd = GenRandom(100, 300);
            float S10006_Rtd = GenRandom(200, 600);
            float S30003_Rtd = GenRandom(100, 500);

            Object[] param2 = new Object[] { QN_val, ST_val, CN_val, PW_val, MN_id, Flag_val, DateTime_val, S20006_Rtd, S30005_Rtd, S30004_Rtd, S10006_Rtd, S30003_Rtd };
            string req_str = string.Format("QN={0};ST={1};CN={2};PW={3};MN={4};Flag={5:G};CP=&&DataTime={6};S20006-Rtd={7};S30005-Rtd={8};S30004-Rtd={9};S10006-Rtd={10};S30003-Rtd={11}", param2);

            
            string str = StrToHexStr(req_str, Encoding.Default);
            byte[] src = Helper.HexStrToArrary(str);
            string CRC_val = Helper.do_CRC(src);

            // 数据包总长度
            string seg_str = $"##{req_str.Length:D4}";

            // 拼装请求
            req_str = seg_str + req_str + CRC_val + "\r\n";
            return req_str;
        }
        
    }
}