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;
		}
	}
}