/*
 *   Copyright (C) 2002-2004,2007-2011,2013,2014-2017,2019 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 "SerialController.h"
#include "Log.h"

#include <cstring>
#include <cassert>

#include <sys/types.h>

#include <sys/ioctl.h>
#include <sys/stat.h>
#include <cerrno>
#include <fcntl.h>
#include <unistd.h>
#include <termios.h>

CSerialController::CSerialController(const std::string& device, SERIAL_SPEED speed, bool assertRTS) :
m_device(device),
m_speed(speed),
m_assertRTS(assertRTS),
m_fd(-1)
{
	assert(!device.empty());
}

CSerialController::~CSerialController()
{
}

bool CSerialController::open()
{
	assert(m_fd == -1);
	
	m_fd = ::open(m_device.c_str(), O_RDWR);
	
	if (m_fd < 0) {
		LogError("Cannot open device - %s", m_device.c_str());
		return false;
	}

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

		termios.c_iflag &= ~(IGNBRK | BRKINT | IGNPAR | PARMRK | INPCK);
		termios.c_iflag &= ~(ISTRIP | INLCR | IGNCR | ICRNL);
		termios.c_iflag &= ~(IXON | IXOFF | IXANY);
		termios.c_oflag &= ~(OPOST);
		termios.c_cflag &= ~(CSTOPB | PARENB | CRTSCTS);
		termios.c_cflag |=  (CS8 | CLOCAL | CREAD);
		termios.c_lflag &= ~(ISIG | ICANON | IEXTEN);
		termios.c_lflag &= ~(ECHO | ECHOE | ECHOK | ECHONL);
		termios.c_cc[VMIN]  = 0;
		termios.c_cc[VTIME] = 1;

		switch (m_speed) {
			case SERIAL_1200:
				::cfsetospeed(&termios, B1200);
				::cfsetispeed(&termios, B1200);
				break;
			case SERIAL_2400:
				::cfsetospeed(&termios, B2400);
				::cfsetispeed(&termios, B2400);
				break;
			case SERIAL_4800:
				::cfsetospeed(&termios, B4800);
				::cfsetispeed(&termios, B4800);
				break;
			case SERIAL_9600:
				::cfsetospeed(&termios, B9600);
				::cfsetispeed(&termios, B9600);
				break;
			case SERIAL_19200:
				::cfsetospeed(&termios, B19200);
				::cfsetispeed(&termios, B19200);
				break;
			case SERIAL_38400:
				::cfsetospeed(&termios, B38400);
				::cfsetispeed(&termios, B38400);
				break;
			case SERIAL_115200:
				::cfsetospeed(&termios, B115200);
				::cfsetispeed(&termios, B115200);
				break;
			case SERIAL_230400:
				::cfsetospeed(&termios, B230400);
				::cfsetispeed(&termios, B230400);
				break;
			case SERIAL_460800:
				::cfsetospeed(&termios, B460800);
				::cfsetispeed(&termios, B460800);
				break;
			default:
				LogError("Unsupported serial port speed - %d", int(m_speed));
				::close(m_fd);
				return false;
		}

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

		if (m_assertRTS) {
			unsigned int y;
			if (::ioctl(m_fd, TIOCMGET, &y) < 0) {
				LogError("Cannot get the control attributes for %s", m_device.c_str());
				::close(m_fd);
				return false;
			}

			y |= TIOCM_RTS;

			if (::ioctl(m_fd, TIOCMSET, &y) < 0) {
				LogError("Cannot set the control attributes for %s", m_device.c_str());
				::close(m_fd);
				return false;
			}
		}
	}

	return true;
}

int CSerialController::read(unsigned char* buffer, unsigned int length)
{
	assert(buffer != NULL);
	assert(m_fd != -1);
	unsigned int ptr = 0;
	/*
	ssize_t len = ::read(m_fd, buffer, length);
	if (len < 0) {
		if (errno != EAGAIN) {
			LogError("Error from read(), errno=%d", errno);
			return -1;
		}
	}
	ptr += len;
	*/
	//while(ptr < length){
		//ssize_t len = ::read(m_fd, buffer + ptr, length - ptr);
		ssize_t len = ::read(m_fd, buffer, length);
		if (len < 0) {
			if (errno != EAGAIN) {
				LogError("Error from read(), errno=%d", errno);
				return -1;
			}
		}
		//if (len > 0)
			//ptr += len;
	//}

	return len;
}

int CSerialController::write(const unsigned char* buffer, unsigned int length)
{
	assert(buffer != NULL);
	assert(m_fd != -1);

	if (length == 0U)
		return 0;

	unsigned int ptr = 0U;
	while (ptr < length) {
		ssize_t len = ::write(m_fd, buffer + ptr, length - ptr);
		if (len < 0) {
			if (errno != EAGAIN) {
				LogError("Error returned from write(), errno=%d", errno);
				return -1;
			}
		}

		if (len > 0)
			ptr += len;
	}

	return ptr;
}

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

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