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

namespace OmronFinsTCP.Net
{
    class FinsClass
    {
        /// <summary>
        /// 获取内存区码
        /// </summary>
        /// <param name="mr">寄存器类型</param>
        /// <param name="mt">地址类型</param>
        /// <returns></returns>
        private static byte GetMemoryCode(PlcMemory mr, MemoryType mt)
        {
            if (mt == MemoryType.Bit)
            {
                switch (mr)
                {
                    case PlcMemory.CIO:
                        return 0x30;
                    case PlcMemory.WR:
                        return 0x31;
                    case PlcMemory.HR:
                        return 0x32;
                    case PlcMemory.AR:
                        return 0x33;  
                    case PlcMemory.DM:
                        return 0x02;
                    default:
                        return 0x00;
                }
            }
            else
            {
                switch (mr)
                {
                    case PlcMemory.CIO:
                        return 0xB0;
                    case PlcMemory.WR:
                        return 0xB1;
                    case PlcMemory.HR:
                        return 0xB2;
                    case PlcMemory.AR:
                        return 0xB3;
                    case PlcMemory.DM:
                        return 0x82;
                    default:
                        return 0x00;
                }
            }
        }

        /// <summary>
        /// PC请求连接的握手信号，第一次连接会分配PC节点号
        /// </summary>
        /// <returns></returns>
        internal static byte[] HandShake()
        {
            #region fins command
            byte[] array = new byte[20];
            array[0] = 0x46;
            array[1] = 0x49;
            array[2] = 0x4E;
            array[3] = 0x53;

            array[4] = 0;
            array[5] = 0;
            array[6] = 0;
            array[7] = 0x0C;

            array[8] = 0;
            array[9] = 0;
            array[10] = 0;
            array[11] = 0;

            array[12] = 0;
            array[13] = 0;
            array[14] = 0;
            array[15] = 0;//ERR？

            array[16] = 0;
            array[17] = 0;
            array[18] = 0;
            array[19] = 0;//TODO:ask for client and server node number, the client node will allocated automatically
            //array[19] = this.GetIPNode(lIP);//本机IP地址的末位
            #endregion fins command
            return array;
        }

        /// <summary>
        /// Fins读写指令生成
        /// </summary>
        /// <param name="rw">读写类型</param>
        /// <param name="mr">寄存器类型</param>
        /// <param name="mt">地址类型</param>
        /// <param name="ch">起始地址</param>
        /// <param name="offset">位地址：00-15,字地址则为00</param>
        /// <param name="cnt">地址个数,按位读写只能是1</param>
        /// <returns></returns>
        internal static byte[] FinsCmd(RorW rw, PlcMemory mr, MemoryType mt, short ch, short offset, short cnt)
        {
            //byte[] array;
            //if (rw == RorW.Read)
            //    array = new byte[34];
            //else
            //    array = new byte[(int)(cnt * 2 + 33 + 1)];//长度是如何确定的在fins协议174页
            byte[] array = new byte[34];//写指令还有后面的写入数组需要拼接在一起！
            //TCP FINS header
            array[0] = 0x46;//F
            array[1] = 0x49;//I
            array[2] = 0x4E;//N
            array[3] = 0x53;//S

            array[4] = 0;//cmd length
            array[5] = 0;
            //指令长度从下面字节开始计算array[8]
            if (rw == RorW.Read)
            {
                array[6] = 0;
                array[7] = 0x1A;//26
            }
            else
            {
                //写数据的时候一个字占两个字节，而一个位只占一个字节
                if (mt == MemoryType.Word)
                {
                    array[6] = (byte)((cnt * 2 + 26) / 256);
                    array[7] = (byte)((cnt * 2 + 26) % 256);
                }
                else
                {
                    array[6] = 0;
                    array[7] = 0x1B;
                }
            }

            array[8] = 0;//frame command
            array[9] = 0;
            array[10] = 0;
            array[11] = 0x02;

            array[12] = 0;//err
            array[13] = 0;
            array[14] = 0;
            array[15] = 0;
            //command frame header
            array[16] = 0x80;//ICF
            array[17] = 0x00;//RSV
            array[18] = 0x02;//GCT, less than 8 network layers
            array[19] = 0x00;//DNA, local network

            array[20] = BasicClass.plcNode;//DA1
            array[21] = 0x00;//DA2, CPU unit
            array[22] = 0x00;//SNA, local network
            array[23] = BasicClass.pcNode;//SA1

            array[24] = 0x00;//SA2, CPU unit
            array[25] = 0xFF;
            //TODO：array[25] = Convert.ToByte(21);//SID//?????----------------------------------00-FF任意值

            //指令码
            if (rw == RorW.Read)
            {
                array[26] = 0x01;//cmdCode--0101
                array[27] = 0x01;
            }
            else
            {
                array[26] = 0x01;//write---0102
                array[27] = 0x02;
            }
            //地址
            //array[28] = (byte)mr;
            array[28] = GetMemoryCode(mr, mt);
            array[29] = (byte)(ch / 256);
            array[30] = (byte)(ch % 256);
            array[31] = (byte)offset;

            array[32] = (byte)(cnt / 256);
            array[33] = (byte)(cnt % 256);

            return array;
        }
    }
}