//	Listener.cpp - Sample application for CSerial
//
//	Copyright (C) 1999-2003 Ramon de Klein (Ramon.de.Klein@ict.nl)
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

#define STRICT
#include <tchar.h>
#include <windows.h>
#include <stdio.h>
#include <string.h>
#include <conio.h>
#include <time.h>
#include "Serial.h"

#define LEVELXBIAS 17
#define LEVELYBIAS 17

int ShowError (LONG lError, LPCTSTR lptszMessage)
{
	// Generate a message text
	TCHAR tszMessage[256];
	wsprintf(tszMessage,_T("%s\n(error code %d)"), lptszMessage, lError);

	// Display message-box and return with an error-code
	::MessageBox(0,tszMessage,_T("Listener"), MB_ICONSTOP|MB_OK);
	return 1;
}

struct STilt
{
	float x, y;
} tilt;

STilt ReadTilt(CSerial &serial)
{
	static STilt tilt = { 0, 0 };
	static int stage = 0; 
	// 0 is ping, 1 wait for ping 
	// 2 is channel 0, 3 is wait for channel 0
	// 4 is request, 5 is wait for request
	// 6 is channel 1, 7 is wait for channel 1
	// 8 is request, 9 is wait for request
	// back to 2
	static time_t ltime = time(NULL); // we also watch the time if it dies after a second we will know
	
	int oldstage=stage;

	LONG lLastError; 

	if ((stage%2)==0) // send
	{
		if (stage==0) serial.Write("P");
		if (stage==2) serial.Write("0");
		if (stage==4 || stage == 8) serial.Write("7");
		if (stage ==6) serial.Write("1");
		stage++;
	}
	else
	{
		// Read data, until there is nothing left
		DWORD dwBytesRead = 0;
		BYTE szBuffer;

		// Read data from the COM-port
		lLastError = serial.Read(&szBuffer,sizeof(szBuffer),&dwBytesRead);
		if (lLastError != ERROR_SUCCESS)
		{
			exit(::ShowError(serial.GetLastError(), _T("Unable to read from COM-port.")));
		}

		if (dwBytesRead == 1)
		{
			int blue = szBuffer;
			// we go from 127 to -128 to 0
			if (blue < 0) blue = 128 + (128 - abs(blue));
			if (stage==5) tilt.x = (float)(blue - 128 + LEVELXBIAS)/30.0f;
			if (stage==9) { tilt.y = (float)(blue-128+LEVELYBIAS)/30.0f; stage = 2;} else 	stage++; 
		}
		else if (stage==3 || stage==7) stage++;
	}

	if (oldstage != stage)
	{
		ltime = time(NULL);
	}
	else
	{
		time_t diff = time(NULL)-ltime;
		if (diff>1000L)
			exit(::ShowError(serial.GetLastError(), _T("My error timeout")));
	}

	return tilt;
}

int __cdecl _tmain (int /*argc*/, char** /*argv*/)
{
    CSerial serial;
	LONG    lLastError = ERROR_SUCCESS;

    // Attempt to open the serial port (COM1)
    lLastError = serial.Open(_T("COM2"),0,0,false);
	if (lLastError != ERROR_SUCCESS)
		return ::ShowError(serial.GetLastError(), _T("Unable to open COM-port"));

    // Setup the serial port (9600,8N1, which is the default setting)
    lLastError = serial.Setup(CSerial::EBaud38400,CSerial::EData8,CSerial::EParNone,CSerial::EStop1);
	if (lLastError != ERROR_SUCCESS)
		return ::ShowError(serial.GetLastError(), _T("Unable to set COM-port setting"));

    // Register only for the receive event
    lLastError = serial.SetMask(CSerial::EEventRecv);
	if (lLastError != ERROR_SUCCESS)
		return ::ShowError(serial.GetLastError(), _T("Unable to set COM-port event mask"));

	// Use 'non-blocking' reads, because we don't know how many bytes
	// will be received. This is normally the most convenient mode
	// (and also the default mode for reading data).
    lLastError = serial.SetupReadTimeouts(CSerial::EReadTimeoutNonblocking);
	if (lLastError != ERROR_SUCCESS)
		return ::ShowError(serial.GetLastError(), _T("Unable to set COM-port read timeout."));

	DWORD dwBytesRead = 0;
	char szBuffer[101];
	while (!kbhit())
	{
		tilt = ReadTilt(serial);
		printf("%+02.3f %+02.3f\n", tilt.x, tilt.y);
		Sleep(10);
	}

	// Close the port again
    serial.Close();
    return 0;
}