// Greg Stitt, Ann Gordon-Ross

//
// Tony Givargis
//

//-----------------------------------------------------------------------------

#include "stdafx.h"
#include <stdio.h>
#include "port.h"
#include "special.h"

//-----------------------------------------------------------------------------

Port::Port(unsigned port, unsigned baud) : DefaultTimeout(1000) {
    
    char buf[32];
    DCB commState;
    
    sprintf(buf, "COM%i", port);
    if( (handle = CreateFile(buf,
			     GENERIC_READ | GENERIC_WRITE,
			     0,
			     0,
			     OPEN_EXISTING,
			     /*FILE_FLAG_OVERLAPPED, */			// 95
				 FILE_ATTRIBUTE_NORMAL,				// NT
			     0)) == INVALID_HANDLE_VALUE ) {
	
	handle = 0;
    }
    else {
	
	GetCommState(handle, &commState);
	commState.BaudRate = baud;
	commState.Parity = NOPARITY;
	commState.StopBits = ONESTOPBIT;
	commState.fDtrControl = DTR_CONTROL_DISABLE;
	commState.fRtsControl = RTS_CONTROL_DISABLE;
	commState.ByteSize = 8;
	SetCommState(handle, &commState);
	EscapeCommFunction(handle, SETDTR);
   	EscapeCommFunction(handle, SETRTS);
	SetTimeout(DefaultTimeout);
    }
}

//-----------------------------------------------------------------------------

Port::~Port() {
    
    if( handle ) {
	
   	CloseHandle(handle);
    }
}

//-----------------------------------------------------------------------------

void
Port::SetTimeout(unsigned ms) {
    
    COMMTIMEOUTS timeout;
    
    if( handle ) {
	
	GetCommTimeouts(handle, &timeout);
	timeout.ReadIntervalTimeout = 0;
	timeout.ReadTotalTimeoutMultiplier = 0;
	timeout.ReadTotalTimeoutConstant = ms;
	SetCommTimeouts(handle, &timeout);
    }
}

//-----------------------------------------------------------------------------

unsigned
Port::Write(void* buf, unsigned szBuf) {
    
    DWORD check = 0;
    
    if( handle ) {
	
   	WriteFile(handle, buf, szBuf, &check, 0);
    }
    return check;
}

//-----------------------------------------------------------------------------

unsigned
Port::Read(void* buf, unsigned szBuf) {
    
    DWORD check = 0;
    
    if( handle ) {
	
   	ReadFile(handle, buf, szBuf, &check, 0);
    }
    return check;
}


/**************************************************/
// Greg and Ann's code

// sends a character

void Port::SendUart(unsigned char d) {
	// send the character

    Write(&d, 1);
	Sleep(25);
}

// calculates a checksum and sends a character

void Port::SendChar(unsigned char d)
{
	static int counter = 0;
	static unsigned char CheckSum = 0;

	if (counter == 0)
		SendUart(BEGIN_PACKET);

	if (d == '\0')
	{
		// fills packet with \0 if eof is reached in the
		// middle of a packet
		
		for(; counter < PACKET_SIZE; counter ++)
		{
			CheckSum ^= '\0';
			SendUart('\0');
		}

		SendUart(CheckSum);
		Sleep(75);

		counter = 0;
		CheckSum = 0;
	}
	else
	{
		// sends character
		
		CheckSum ^= d;
		SendUart(d);
		counter ++;

		if (counter == PACKET_SIZE)
		{
			SendUart(CheckSum);
			Sleep(75);
			counter = 0;
			CheckSum = 0;
		}
	}
}

// sends an entire string

void Port::SendStringUart(const char* s) {

    while( *s ) {
		SendChar(*s++);
	}

	SendChar('\0');
}