using System;
using System.Runtime.InteropServices;

namespace JustinIO
{
    class CommPort
    {

        public string PortNum;
        public int BaudRate;
        public byte ByteSize;
        public byte Parity; // 0-4=no,odd,even,mark,space 
        public byte StopBits; // 0,1,2 = 1, 1.5, 2 
        public int ReadTimeout;

        //comm port win32 file handle
        private int hComm = -1;

        public bool Opened = false;

        //win32 api constants
        private const uint GENERIC_READ = 0x80000000;
        private const uint GENERIC_WRITE = 0x40000000;
        private const int OPEN_EXISTING = 3;
        private const int INVALID_HANDLE_VALUE = -1;

        [StructLayout(LayoutKind.Sequential)]
        public struct DCB
        {
            //taken from c struct in platform sdk 
            public int DCBlength;            // sizeof(DCB) 
            public int BaudRate;             // 指定當前波特率 current baud rate
            // these are the c struct bit fields, bit twiddle flag to set
            public int fBinary;           // 指定是否允許二進制模式,在windows95中必須主TRUE binary mode, no EOF check 
            public int fParity;           // 指定是否允許奇偶校驗 enable parity checking 
            public int fOutxCtsFlow;       // 指定CTS是否用于檢測發送控制，當為TRUE是CTS為OFF，發送將被掛起。 CTS output flow control 
            public int fOutxDsrFlow;       // 指定CTS是否用于檢測發送控制 DSR output flow control 
            public int fDtrControl;        // DTR_CONTROL_DISABLE值將DTR置為OFF, DTR_CONTROL_ENABLE值將DTR置為ON, DTR_CONTROL_HANDSHAKE允許DTR"握手" DTR flow control type 
            public int fDsrSensitivity;    // 當該值為TRUE時DSR為OFF時接收的字節被忽略 DSR sensitivity 
            public int fTXContinueOnXoff; // 指定當接收緩沖區已滿,并且驅動程序已經發送出XoffChar字符時發送是否停止。TRUE時，在接收緩沖區接收到緩沖區已滿的字節XoffLim且驅動程序已經發送出XoffChar字符中止接收字節之后，發送繼續進行。　FALSE時，在接收緩沖區接收到代表緩沖區已空的字節XonChar且驅動程序已經發送出恢復發送的XonChar之后，發送繼續進行。XOFF continues Tx 
            public int fOutX;           // TRUE時，接收到XoffChar之后便停止發送接收到XonChar之后將重新開始 XON/XOFF out flow control 
            public int fInX;            // TRUE時，接收緩沖區接收到代表緩沖區滿的XoffLim之后，XoffChar發送出去接收緩沖區接收到代表緩沖區空的XonLim之后，XonChar發送出去 XON/XOFF in flow control 
            public int fErrorChar;      // 該值為TRUE且fParity為TRUE時，用ErrorChar 成員指定的字符代替奇偶校驗錯誤的接收字符 enable error replacement 
            public int fNull;           // eTRUE時，接收時去掉空（0值）字節 enable null stripping 
            public int fRtsControl;      // RTS flow control 
            /*RTS_CONTROL_DISABLE時,RTS置為OFF
            RTS_CONTROL_ENABLE時, RTS置為ON
        RTS_CONTROL_HANDSHAKE時,
        當接收緩沖區小于半滿時RTS為ON
            當接收緩沖區超過四分之三滿時RTS為OFF
        RTS_CONTROL_TOGGLE時,
        當接收緩沖區仍有剩余字節時RTS為ON ,否則缺省為OFF*/

            public int fAbortOnError;    // TRUE時,有錯誤發生時中止讀和寫操作 abort on error 
            public int fDummy2;         // 未使用 reserved 

            public uint flags;
            public ushort wReserved;           // 未使用,必須為0 not currently used 
            public ushort XonLim;              // 指定在XON字符發送這前接收緩沖區中可允許的最小字節數 transmit XON threshold 
            public ushort XoffLim;             // 指定在XOFF字符發送這前接收緩沖區中可允許的最小字節數 transmit XOFF threshold 
            public byte ByteSize;            // 指定端口當前使用的數據位 number of bits/byte, 4-8 
            public byte Parity;              // 指定端口當前使用的奇偶校驗方法,可能為:EVENPARITY,MARKPARITY,NOPARITY,ODDPARITY   0-4=no,odd,even,mark,space 
            public byte StopBits;            // 指定端口當前使用的停止位數,可能為:ONESTOPBIT,ONE5STOPBITS,TWOSTOPBITS   0,1,2 = 1, 1.5, 2 
            public char XonChar;             // 指定用于發送和接收字符XON的值 Tx and Rx XON character 
            public char XoffChar;            // 指定用于發送和接收字符XOFF值 Tx and Rx XOFF character 
            public char ErrorChar;           // 本字符用來代替接收到的奇偶校驗發生錯誤時的值 error replacement character 
            public char EofChar;             // 當沒有使用二進制模式時,本字符可用來指示數據的結束 end of input character 
            public char EvtChar;             // 當接收到此字符時,會產生一個事件 received event character 
            public ushort wReserved1;          // 未使用 reserved; do not use 
        }

        [StructLayout(LayoutKind.Sequential)]
        private struct COMMTIMEOUTS
        {
            public int ReadIntervalTimeout;
            public int ReadTotalTimeoutMultiplier;
            public int ReadTotalTimeoutConstant;
            public int WriteTotalTimeoutMultiplier;
            public int WriteTotalTimeoutConstant;
        }

        [StructLayout(LayoutKind.Sequential)]
        private struct OVERLAPPED
        {
            public int Internal;
            public int InternalHigh;
            public int Offset;
            public int OffsetHigh;
            public int hEvent;
        }

        [DllImport("kernel32.dll")]
        private static extern int CreateFile(
          string lpFileName,                          // 要打開的串口名稱
          uint dwDesiredAccess,                       // 指定串口的訪問方式，一般設置為可讀可寫方式
          int dwShareMode,                           // 指定串口的共享模式，串口不能共享，所以設置為0
          int lpSecurityAttributes, // 設置串口的安全屬性，WIN9X下不支持，應設為NULL
          int dwCreationDisposition,                 // 對于串口通信，創建方式只能為OPEN_EXISTING
          int dwFlagsAndAttributes,                  // 指定串口屬性與標志，設置為FILE_FLAG_OVERLAPPED(重疊I/O操作)，指定串口以異步方式通信
          int hTemplateFile                         // 對于串口通信必須設置為NULL
        );
        [DllImport("kernel32.dll")]
        private static extern bool GetCommState(
          int hFile,   //通信設備句柄
          ref DCB lpDCB     // 設備控制塊DCB
        );
        [DllImport("kernel32.dll")]
        private static extern bool BuildCommDCB(
          string lpDef,   // 設備控制字符串
          ref DCB lpDCB      // 設備控制塊
        );
        [DllImport("kernel32.dll")]
        private static extern bool SetCommState(
          int hFile,   // 通信設備句柄
          ref DCB lpDCB     // 設備控制塊
        );
        [DllImport("kernel32.dll")]
        private static extern bool GetCommTimeouts(
          int hFile,                   // 通信設備句柄 handle to comm device
          ref COMMTIMEOUTS lpCommTimeouts   // 超時時間 time-out values
        );
        [DllImport("kernel32.dll")]
        private static extern bool SetCommTimeouts(
          int hFile,                   // 通信設備句柄 handle to comm device
          ref COMMTIMEOUTS lpCommTimeouts   // 超時時間 time-out values
        );
        [DllImport("kernel32.dll")]
        private static extern bool ReadFile(
          int hFile,                 // 通信設備句柄 handle to file
          byte[] lpBuffer,              // 數據緩沖區 data buffer
          int nNumberOfBytesToRead,   // 多少字節等待讀取 number of bytes to read
          ref int lpNumberOfBytesRead, // 讀取多少字節 number of bytes read
          ref OVERLAPPED lpOverlapped     // 溢出緩沖區 overlapped buffer
        );
        [DllImport("kernel32.dll")]
        private static extern bool WriteFile(
          int hFile,                     // 通信設備句柄 handle to file
          byte[] lpBuffer,                 // 數據緩沖區 data buffer
          int nNumberOfBytesToWrite,      // 多少字節等待寫入 number of bytes to write
          ref int lpNumberOfBytesWritten,   // 已經寫入多少字節 number of bytes written
          ref OVERLAPPED lpOverlapped         // 溢出緩沖區 overlapped buffer
        );
        [DllImport("kernel32.dll")]
        private static extern bool CloseHandle(
          int hObject    // handle to object
        );
        [DllImport("kernel32.dll")]
        private static extern uint GetLastError();

        public void Open()
        {

            DCB dcbCommPort = new DCB();
            COMMTIMEOUTS ctoCommPort = new COMMTIMEOUTS();

            // 打開串口 OPEN THE COMM PORT.
            hComm = CreateFile(PortNum, GENERIC_READ | GENERIC_WRITE, 0, 0, OPEN_EXISTING, 0, 0);
            // 如果串口沒有打開，就打開 IF THE PORT CANNOT BE OPENED, BAIL OUT.
            if (hComm == INVALID_HANDLE_VALUE)
            {
                throw (new ApplicationException("非法操作，不能打開串口！"));
            }

            // 設置通信超時時間 SET THE COMM TIMEOUTS.
            GetCommTimeouts(hComm, ref ctoCommPort);
            ctoCommPort.ReadTotalTimeoutConstant = ReadTimeout;
            ctoCommPort.ReadTotalTimeoutMultiplier = 0;
            ctoCommPort.WriteTotalTimeoutMultiplier = 0;
            ctoCommPort.WriteTotalTimeoutConstant = 0;
            SetCommTimeouts(hComm, ref ctoCommPort);

            // 設置串口 SET BAUD RATE, PARITY, WORD SIZE, AND STOP BITS.
            GetCommState(hComm, ref dcbCommPort);
            dcbCommPort.BaudRate = BaudRate;
            dcbCommPort.flags = 0;
            //dcb.fBinary=1;
            dcbCommPort.flags |= 1;
            if (Parity > 0)
            {
                //dcb.fParity=1
                dcbCommPort.flags |= 2;
            }
            dcbCommPort.Parity = Parity;
            dcbCommPort.ByteSize = ByteSize;
            dcbCommPort.StopBits = StopBits;
            if (!SetCommState(hComm, ref dcbCommPort))
            {
                //uint ErrorNum=GetLastError();
                throw (new ApplicationException("非法操作，不能打開串口！"));
            }
            //unremark to see if setting took correctly
            //DCB dcbCommPort2 = new DCB();
            //GetCommState(hComm, ref dcbCommPort2);
            Opened = true;
        }

        public void Close()
        {
            if (hComm != INVALID_HANDLE_VALUE)
            {
                CloseHandle(hComm);
            }
        }

        public byte[] Read(int NumBytes)
        {
            byte[] BufBytes;
            byte[] OutBytes;
            BufBytes = new byte[NumBytes];
            if (hComm != INVALID_HANDLE_VALUE)
            {
                OVERLAPPED ovlCommPort = new OVERLAPPED();
                int BytesRead = 0;
                ReadFile(hComm, BufBytes, NumBytes, ref BytesRead, ref ovlCommPort);
                OutBytes = new byte[BytesRead];
                Array.Copy(BufBytes, OutBytes, BytesRead);
            }
            else
            {
                throw (new ApplicationException("串口未打開！"));
            }
            return OutBytes;
        }

        public void Write(byte[] WriteBytes)
        {
            if (hComm != INVALID_HANDLE_VALUE)
            {
                OVERLAPPED ovlCommPort = new OVERLAPPED();
                int BytesWritten = 0;
                WriteFile(hComm, WriteBytes, WriteBytes.Length, ref BytesWritten, ref ovlCommPort);
            }
            else
            {
                throw (new ApplicationException("串口未打開！"));
            }
        }
    }

    class HexCon
    {
        // 把十六進制字符串轉換成字節型和把字節型轉換成十六進制字符串 converter hex string to byte and byte to hex string
        public static string ByteToString(byte[] InBytes)
        {
            string StringOut = "";
            foreach (byte InByte in InBytes)
            {
                StringOut = StringOut + String.Format("{0:X2} ", InByte);
            }
            return StringOut;
        }
        public static byte[] StringToByte(string InString)
        {
            string[] ByteStrings;
            ByteStrings = InString.Split(" ".ToCharArray());
            byte[] ByteOut;
            ByteOut = new byte[ByteStrings.Length - 1];
            for (int i = 0; i == ByteStrings.Length - 1; i++)
            {
                ByteOut[i] = Convert.ToByte(("0x" + ByteStrings[i]));
            }
            return ByteOut;
        }
    }
}