/*
 *   Copyright (C) 2002-2004,2007-2011,2013,2015 by Jonathan Naylor G4KLX
 *   Copyright (C) 1999-2001 by Thomas Sailor HB9JNX
 *
 *   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.
 */

#include "SerialLineController.h"

#if !defined(_WIN32)
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <cerrno>
#include <fcntl.h>
#include <unistd.h>
#include <termios.h>
#endif


#if !defined(_WIN32)

CSerialLineController::CSerialLineController(const std::string& device, unsigned int config) :
m_device(device),
m_config(config),
m_rts(false),
m_dtr(false),
m_fd(-1)
{
	assert(!device.empty());
	assert(config == 1U || config == 2U || config == 3U);
}

CSerialLineController::~CSerialLineController()
{
}

bool CSerialLineController::open()
{
	assert(m_fd == -1);

	m_fd = ::open(m_device.c_str(), O_RDWR | O_NOCTTY | O_NDELAY, 0);
	if (m_fd < 0) {
		::fprintf(stderr, "Cannot open device - %s\n", m_device.c_str());
		return false;
	}

	if (::isatty(m_fd) == 0) {
		::fprintf(stderr, "%s is not a TTY device\n", m_device.c_str());
		::close(m_fd);
		return false;
	}

	termios termios;
	if (::tcgetattr(m_fd, &termios) < 0) {
		::fprintf(stderr, "Cannot get the attributes for %s\n", m_device.c_str());
		::close(m_fd);
		return false;
	}

	// FIXME XXX unfinished
	termios.c_cflag |= (CLOCAL | CREAD);
	termios.c_cflag &= ~CRTSCTS;
	termios.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG);
	termios.c_oflag &= ~OPOST;
	termios.c_cc[VMIN]  = 0;
	termios.c_cc[VTIME] = 10;

	if (::tcsetattr(m_fd, TCSANOW, &termios) < 0) {
		::fprintf(stderr, "Cannot set the attributes for %s\n", m_device.c_str());
		::close(m_fd);
		return false;
	}

	unsigned int y;
	if (::ioctl(m_fd, TIOCMGET, &y) < 0) {
		::fprintf(stderr, "Cannot get the modem status bits for %s\n", m_device.c_str());
		::close(m_fd);
		return false;
	}

	y &= ~TIOCM_DTR;
	y &= ~TIOCM_RTS;

	if (::ioctl(m_fd, TIOCMSET, &y) < 0) {
		::fprintf(stderr, "Cannot set the modem status bits for %s\n", m_device.c_str());
		::close(m_fd);
		return false;
	}

	return true;
}

bool CSerialLineController::getCD() const
{
	assert(m_fd != -1);

	unsigned int y;
	if (::ioctl(m_fd, TIOCMGET, &y) < 0)
		return false;

	return (y & TIOCM_CD) == TIOCM_CD;
}

bool CSerialLineController::getCTS() const
{
	assert(m_fd != -1);

	unsigned int y;
	if (::ioctl(m_fd, TIOCMGET, &y) < 0)
		return false;

	return (y & TIOCM_CTS) == TIOCM_CTS;
}

bool CSerialLineController::getDSR() const
{
	assert(m_fd != -1);

	unsigned int y;
	if (::ioctl(m_fd, TIOCMGET, &y) < 0)
		return false;

	return (y & TIOCM_DSR) == TIOCM_DSR;
}

bool CSerialLineController::setRTS(bool set)
{
	assert(m_fd != -1);

	if (set == m_rts)
		return true;

	unsigned int y;
	if (::ioctl(m_fd, TIOCMGET, &y) < 0)
		return false;

	if (set)
		y |= TIOCM_RTS;
	else
		y &= ~TIOCM_RTS;

	if (::ioctl(m_fd, TIOCMSET, &y) < 0)
		return false;

	m_rts = set;

	return true;
}

bool CSerialLineController::setDTR(bool set)
{
	assert(m_fd != -1);

	if (set == m_dtr)
		return true;

	unsigned int y;
	if (::ioctl(m_fd, TIOCMGET, &y) < 0)
		return false;

	if (set)
		y |= TIOCM_DTR;
	else
		y &= ~TIOCM_DTR;

	if (::ioctl(m_fd, TIOCMSET, &y) < 0)
		return false;

	m_dtr = set;

	return true;
}

void CSerialLineController::getDigitalInputs(bool& inp1, bool& inp2, bool& inp3, bool& inp4, bool& inp5)
{
	assert(m_fd != -1);

	inp1 = inp2 = inp3 = inp4 = inp5 = false;

	unsigned int y;
	if (::ioctl(m_fd, TIOCMGET, &y) < 0)
		return;

	switch (m_config) {
		case 1U:
			inp1 = (y & TIOCM_DSR) == TIOCM_DSR;
			inp2 = (y & TIOCM_CTS) == TIOCM_CTS;
			break;
		case 2U:
			inp1 = (y & TIOCM_CD) == TIOCM_CD;
			inp2 = (y & TIOCM_CD) == TIOCM_CD;
			break;
		case 3U:
			inp1 = (y & TIOCM_CD) == TIOCM_CD;
			break;
		default:
			::fprintf(stderr, "Unknown serial config - %u\n", m_config);
			break;
	}
}

void CSerialLineController::setDigitalOutputs(bool outp1, bool, bool outp3, bool, bool, bool, bool, bool)
{
	assert(m_fd != -1);

	if (m_config == 1U) {
		if (outp1 == m_dtr && outp3 == m_rts)
			return;

		unsigned int y;
		if (::ioctl(m_fd, TIOCMGET, &y) < 0)
			return;

		if (outp1)
			y |= TIOCM_DTR;
		else
			y &= ~TIOCM_DTR;

		if (outp3)
			y |= TIOCM_RTS;
		else
			y &= ~TIOCM_RTS;

		if (::ioctl(m_fd, TIOCMSET, &y) < 0)
			return;

		m_dtr = outp1;
		m_rts = outp3;
	} else if (m_config == 2U || m_config == 3U) {
		if (outp1 == m_rts && outp3 == m_dtr)
			return;

		unsigned int y;
		if (::ioctl(m_fd, TIOCMGET, &y) < 0)
			return;

		if (outp1)
			y |= TIOCM_RTS;
		else
			y &= ~TIOCM_RTS;

		if (outp3)
			y |= TIOCM_DTR;
		else
			y &= ~TIOCM_DTR;

		if (::ioctl(m_fd, TIOCMSET, &y) < 0)
			return;

		m_rts = outp1;
		m_dtr = outp3;
	} else {
		::fprintf(stderr, "Unknown serial config - %u\n", m_config);
	}
}

void CSerialLineController::close()
{
	assert(m_fd != -1);

	::close(m_fd);
	m_fd = -1;
}

#else // _WIN32

CSerialLineController::CSerialLineController(const std::string& device, unsigned int config) :
m_device(device),
m_config(config),
m_rts(false),
m_dtr(false),
m_handle(INVALID_HANDLE_VALUE)
{
	assert(!device.empty());
	assert(config == 1U || config == 2U || config == 3U);
}

CSerialLineController::~CSerialLineController()
{
}

bool CSerialLineController::open()
{
	assert(m_handle == INVALID_HANDLE_VALUE);

	// On Windows, ports above COM9 require the \\.\COMn prefix.
	std::string path = "\\\\.\\" + m_device;

	m_handle = ::CreateFileA(path.c_str(),
	                         GENERIC_READ | GENERIC_WRITE,
	                         0,
	                         nullptr,
	                         OPEN_EXISTING,
	                         FILE_ATTRIBUTE_NORMAL,
	                         nullptr);
	if (m_handle == INVALID_HANDLE_VALUE) {
		::fprintf(stderr, "Cannot open device - %s\n", m_device.c_str());
		return false;
	}

	// Deassert both DTR and RTS on open, matching the POSIX behaviour.
	::EscapeCommFunction(m_handle, CLRDTR);
	::EscapeCommFunction(m_handle, CLRRTS);

	m_rts = false;
	m_dtr = false;

	return true;
}

bool CSerialLineController::getCD() const
{
	assert(m_handle != INVALID_HANDLE_VALUE);

	DWORD status = 0U;
	if (!::GetCommModemStatus(m_handle, &status))
		return false;

	return (status & MS_RLSD_ON) != 0U;
}

bool CSerialLineController::getCTS() const
{
	assert(m_handle != INVALID_HANDLE_VALUE);

	DWORD status = 0U;
	if (!::GetCommModemStatus(m_handle, &status))
		return false;

	return (status & MS_CTS_ON) != 0U;
}

bool CSerialLineController::getDSR() const
{
	assert(m_handle != INVALID_HANDLE_VALUE);

	DWORD status = 0U;
	if (!::GetCommModemStatus(m_handle, &status))
		return false;

	return (status & MS_DSR_ON) != 0U;
}

bool CSerialLineController::setRTS(bool set)
{
	assert(m_handle != INVALID_HANDLE_VALUE);

	if (set == m_rts)
		return true;

	if (!::EscapeCommFunction(m_handle, set ? SETRTS : CLRRTS))
		return false;

	m_rts = set;

	return true;
}

bool CSerialLineController::setDTR(bool set)
{
	assert(m_handle != INVALID_HANDLE_VALUE);

	if (set == m_dtr)
		return true;

	if (!::EscapeCommFunction(m_handle, set ? SETDTR : CLRDTR))
		return false;

	m_dtr = set;

	return true;
}

void CSerialLineController::getDigitalInputs(bool& inp1, bool& inp2, bool& inp3, bool& inp4, bool& inp5)
{
	assert(m_handle != INVALID_HANDLE_VALUE);

	inp1 = inp2 = inp3 = inp4 = inp5 = false;

	DWORD status = 0U;
	if (!::GetCommModemStatus(m_handle, &status))
		return;

	switch (m_config) {
		case 1U:
			inp1 = (status & MS_DSR_ON)  != 0U;
			inp2 = (status & MS_CTS_ON)  != 0U;
			break;
		case 2U:
			inp1 = (status & MS_RLSD_ON) != 0U;
			inp2 = (status & MS_RLSD_ON) != 0U;
			break;
		case 3U:
			inp1 = (status & MS_RLSD_ON) != 0U;
			break;
		default:
			::fprintf(stderr, "Unknown serial config - %u\n", m_config);
			break;
	}
}

void CSerialLineController::setDigitalOutputs(bool outp1, bool, bool outp3, bool, bool, bool, bool, bool)
{
	assert(m_handle != INVALID_HANDLE_VALUE);

	if (m_config == 1U) {
		if (outp1 == m_dtr && outp3 == m_rts)
			return;

		::EscapeCommFunction(m_handle, outp1 ? SETDTR : CLRDTR);
		::EscapeCommFunction(m_handle, outp3 ? SETRTS : CLRRTS);

		m_dtr = outp1;
		m_rts = outp3;
	} else if (m_config == 2U || m_config == 3U) {
		if (outp1 == m_rts && outp3 == m_dtr)
			return;

		::EscapeCommFunction(m_handle, outp1 ? SETRTS : CLRRTS);
		::EscapeCommFunction(m_handle, outp3 ? SETDTR : CLRDTR);

		m_rts = outp1;
		m_dtr = outp3;
	} else {
		::fprintf(stderr, "Unknown serial config - %u\n", m_config);
	}
}

void CSerialLineController::close()
{
	assert(m_handle != INVALID_HANDLE_VALUE);

	::CloseHandle(m_handle);
	m_handle = INVALID_HANDLE_VALUE;
}

#endif // _WIN32