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

namespace BatCharging.Service
{
    public static class PublicProgram
    {
        public static string failName01 = null;
        public static string failName02 = null;
        public static string failName03 = null;
        public static string failName04 = null;

        public static List<byte> APCI(APDUModel baseApci)
        {
            List<byte> lstResult = null;
            if (baseApci != null)
            {
                lstResult = new List<byte>();
                //起始域
                lstResult.Add(baseApci.OriginDomain1);
                lstResult.Add(baseApci.OriginDomain2);
                //长度域
                byte[] packLens = BitConverter.GetBytes(baseApci.LengthDomain);
                lstResult.AddRange(packLens);
                //信息域                
                lstResult.Add(baseApci.infoDomain);
                //序列号域
                lstResult.Add(baseApci.SerialNumberDomain);
                //源地址
                byte[] packSrcs = BitConverter.GetBytes(baseApci.CMD);
                lstResult.AddRange(packSrcs);
                //数据域
                lstResult.AddRange(baseApci.dataDomain);

                baseApci.checksumDomain = checksumDomain(lstResult.ToArray());
                //校验和域
                lstResult.Add(baseApci.checksumDomain);
            }
            return lstResult;
        }
        /// <summary>
        /// 数据包发送-计算校验和
        /// </summary>
        /// <param name="data"></param>
        /// <returns></returns>
        public static byte checksumDomain(byte[] data)
        {
            int checksum = 0;

            for (int i = 6; i < data.Count(); i++)//这里没校验域所以不减一
            {
                checksum += data[i];
            }

            //foreach (byte b in data)
            //{
            //    checksum += b;
            //}
            // 取校验和的低8位  
            return (byte)(checksum & 0xFF);
        }
        /// <summary>
        /// 数据包接收-判断校验和是否正确-即判断数据是否完整
        /// </summary>
        /// <param name="data"></param>
        /// <returns></returns>
        public static bool checksumDomainReceive(byte[] data)
        {
            bool bResult = false;
            int checksum = 0;

            for (int i = 8; i < data.Count() - 1; i++)//这里有校验域所以减一
            {
                checksum += data[i];
            }

            //foreach (byte b in data)
            //{
            //    checksum += b;
            //}
            // 取校验和的低8位  
            if (data[data.Count()-1] == (byte)(checksum & 0xFF))
                bResult = true;
            return bResult;
        }

        public static ushort ComputeHeaderIpChecksum(byte[] header, int start, int length)
        {

            ushort word16;
            long sum = 0;
            for (int i = start; i < (length + start); i += 2)
            {
                word16 = (ushort)(((header[i] << 8) & 0xFF00)
                + (header[i + 1] & 0xFF));
                sum += (long)word16;
            }

            while ((sum >> 16) != 0)
            {
                sum = (sum & 0xFFFF) + (sum >> 16);
            }

            sum = ~sum;

            return (ushort)sum;


        }

    }
}