/*
*   Copyright (C) 2016,2017,2018 by Jonathan Naylor G4KLX
*
*   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 "YSFGateway.h"
#include "YSFReflectors.h"
#include "UDPSocket.h"
#include "StopWatch.h"
#include "Version.h"
#include "YSFFICH.h"
#include "Thread.h"
#include "Timer.h"
#include "Log.h"

#if defined(_WIN32) || defined(_WIN64)
#include <Windows.h>
#else
#include <sys/time.h>
#include <unistd.h>
#include <signal.h>
#include <fcntl.h>
#include <pwd.h>
#endif

#if defined(_WIN32) || defined(_WIN64)
const char* DEFAULT_INI_FILE = "YSFGateway.ini";
#else
const char* DEFAULT_INI_FILE = "/etc/YSFGateway.ini";
#endif

#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <clocale>

int main(int argc, char** argv)
{
	const char* iniFile = DEFAULT_INI_FILE;
	if (argc > 1) {
		for (int currentArg = 1; currentArg < argc; ++currentArg) {
			std::string arg = argv[currentArg];
			if ((arg == "-v") || (arg == "--version")) {
				::fprintf(stdout, "YSFGateway version %s\n", VERSION);
				return 0;
			} else if (arg.substr(0, 1) == "-") {
				::fprintf(stderr, "Usage: YSFGateway [-v|--version] [filename]\n");
				return 1;
			} else {
				iniFile = argv[currentArg];
			}
		}
	}

	CYSFGateway* gateway = new CYSFGateway(std::string(iniFile));

	int ret = gateway->run();

	delete gateway;

	return ret;
}

CYSFGateway::CYSFGateway(const std::string& configFile) :
m_callsign(),
m_suffix(),
m_conf(configFile),
m_gps(NULL),
m_wiresX(NULL),
m_dtmf(NULL),
m_ysfNetwork(NULL),
m_linked(false),
m_exclude(false)
{
}

CYSFGateway::~CYSFGateway()
{
}

int CYSFGateway::run()
{
	bool ret = m_conf.read();
	if (!ret) {
		::fprintf(stderr, "YSFGateway: cannot read the .ini file\n");
		return 1;
	}

	setlocale(LC_ALL, "C");

	ret = ::LogInitialise(m_conf.getLogFilePath(), m_conf.getLogFileRoot(), m_conf.getLogFileLevel(), m_conf.getLogDisplayLevel());
	if (!ret) {
		::fprintf(stderr, "YSFGateway: unable to open the log file\n");
		return 1;
	}

#if !defined(_WIN32) && !defined(_WIN64)
	bool m_daemon = m_conf.getDaemon();
	if (m_daemon) {
		// Create new process
		pid_t pid = ::fork();
		if (pid == -1) {
			::LogWarning("Couldn't fork() , exiting");
			return -1;
		} else if (pid != 0)
			exit(EXIT_SUCCESS);

		// Create new session and process group
		if (::setsid() == -1) {
			::LogWarning("Couldn't setsid(), exiting");
			return -1;
		}

		// Set the working directory to the root directory
		if (::chdir("/") == -1) {
			::LogWarning("Couldn't cd /, exiting");
			return -1;
		}

		::close(STDIN_FILENO);
		::close(STDOUT_FILENO);
		::close(STDERR_FILENO);

		//If we are currently root...
		if (getuid() == 0) {
			struct passwd* user = ::getpwnam("mmdvm");
			if (user == NULL) {
				::LogError("Could not get the mmdvm user, exiting");
				return -1;
			}

			uid_t mmdvm_uid = user->pw_uid;
			gid_t mmdvm_gid = user->pw_gid;

			//Set user and group ID's to mmdvm:mmdvm
			if (setgid(mmdvm_gid) != 0) {
				::LogWarning("Could not set mmdvm GID, exiting");
				return -1;
			}

			if (setuid(mmdvm_uid) != 0) {
				::LogWarning("Could not set mmdvm UID, exiting");
				return -1;
			}

			//Double check it worked (AKA Paranoia) 
			if (setuid(0) != -1) {
				::LogWarning("It's possible to regain root - something is wrong!, exiting");
				return -1;
			}
		}
	}
#endif

	m_callsign = m_conf.getCallsign();
	m_suffix   = m_conf.getSuffix();

	bool debug            = m_conf.getNetworkDebug();
	in_addr rptAddress    = CUDPSocket::lookup(m_conf.getRptAddress());
	unsigned int rptPort  = m_conf.getRptPort();
	std::string myAddress = m_conf.getMyAddress();
	unsigned int myPort   = m_conf.getMyPort();

	CYSFNetwork rptNetwork(myAddress, myPort, m_callsign, debug);
	rptNetwork.setDestination(rptAddress, rptPort);

	ret = rptNetwork.open();
	if (!ret) {
		::LogError("Cannot open the repeater network port");
		::LogFinalise();
		return 1;
	}

	unsigned int netPort = m_conf.getNetworkPort();

	m_ysfNetwork = new CYSFNetwork(netPort, m_callsign, debug);
	ret = m_ysfNetwork->open();
	if (!ret) {
		::LogError("Cannot open the YSF reflector network port");
		::LogFinalise();
		return 1;
	}

	CTimer inactivityTimer(1000U, m_conf.getNetworkInactivityTimeout() * 60U);
	CTimer lostTimer(1000U, 120U);
	CTimer pollTimer(1000U, 5U);

	bool revert = m_conf.getNetworkRevert();
	std::string startup = m_conf.getNetworkStartup();

	bool networkEnabled = m_conf.getNetworkEnabled();
	if (networkEnabled) {
		std::string fileName = m_conf.getNetworkHosts();
		unsigned int reloadTime = m_conf.getNetworkReloadTime();

		m_wiresX = new CWiresX(m_callsign, m_suffix, &rptNetwork, fileName, reloadTime);
		m_dtmf   = new CDTMF;

		std::string name         = m_conf.getName();
		unsigned int txFrequency = m_conf.getTxFrequency();
		unsigned int rxFrequency = m_conf.getRxFrequency();

		m_wiresX->setInfo(name, txFrequency, rxFrequency);

		std::string address = m_conf.getNetworkParrotAddress();
		unsigned int port = m_conf.getNetworkParrotPort();

		if (port > 0U)
			m_wiresX->setParrot(address, port);

		address = m_conf.getNetworkYSF2DMRAddress();
		port = m_conf.getNetworkYSF2DMRPort();

		if (port > 0U)
			m_wiresX->setYSF2DMR(address, port);

		m_wiresX->start();

		if (!startup.empty()) {
			CYSFReflector* reflector = m_wiresX->getReflector(startup);
			if (reflector != NULL) {
				LogMessage("Automatic connection to %5.5s - \"%s\"", reflector->m_id.c_str(), reflector->m_name.c_str());

				m_ysfNetwork->setDestination(reflector->m_address, reflector->m_port);
				m_ysfNetwork->writePoll();
				m_ysfNetwork->writePoll();
				m_ysfNetwork->writePoll();

				if (!revert)
					inactivityTimer.start();

				lostTimer.start();
				pollTimer.start();

				m_linked = true;
			}
		}
	}

	CStopWatch stopWatch;
	stopWatch.start();

	LogMessage("Starting YSFGateway-%s", VERSION);

	createGPS();

	for (;;) {
		unsigned char buffer[200U];

		while (rptNetwork.read(buffer) > 0U) {
			CYSFFICH fich;
			bool valid = fich.decode(buffer + 35U);
			if (valid) {
				unsigned char fi = fich.getFI();
				unsigned char dt = fich.getDT();
				unsigned char fn = fich.getFN();
				unsigned char ft = fich.getFT();

				// Don't send out control data
				m_exclude = (dt == YSF_DT_DATA_FR_MODE);

				if (m_wiresX != NULL) {
					WX_STATUS status = m_wiresX->process(buffer + 35U, buffer + 14U, fi, dt, fn, ft);
					switch (status) {
					case WXS_CONNECT: {
							m_ysfNetwork->writeUnlink();
							m_ysfNetwork->writeUnlink();
							m_ysfNetwork->writeUnlink();

							CYSFReflector* reflector = m_wiresX->getReflector();
							LogMessage("Connect to %5.5s - \"%s\" has been requested by %10.10s", reflector->m_id.c_str(), reflector->m_name.c_str(), buffer + 14U);

							m_ysfNetwork->setDestination(reflector->m_address, reflector->m_port);
							m_ysfNetwork->writePoll();
							m_ysfNetwork->writePoll();
							m_ysfNetwork->writePoll();

							inactivityTimer.start();
							lostTimer.start();
							pollTimer.start();

							m_linked = true;
						}
						break;
					case WXS_DISCONNECT:
						LogMessage("Disconnect has been requested by %10.10s", buffer + 14U);

						m_ysfNetwork->writeUnlink();
						m_ysfNetwork->writeUnlink();
						m_ysfNetwork->writeUnlink();
						m_ysfNetwork->clearDestination();

						inactivityTimer.stop();
						lostTimer.stop();
						pollTimer.stop();

						m_linked = false;
						break;
					default:
						break;
					}

					status = WXS_NONE;
					switch (dt) {
					case YSF_DT_VD_MODE2:
						status = m_dtmf->decodeVDMode2(buffer + 35U, (buffer[34U] & 0x01U) == 0x01U);
						break;
					default:
						break;
					}

					switch (status) {
					case WXS_CONNECT: {
						std::string id = m_dtmf->getReflector();
						CYSFReflector* reflector = m_wiresX->getReflector(id);
						if (reflector != NULL) {
							m_wiresX->processConnect(reflector);

							if (m_linked) {
								m_ysfNetwork->writeUnlink();
								m_ysfNetwork->writeUnlink();
								m_ysfNetwork->writeUnlink();
							}

							LogMessage("Connect via DTMF to %5.5s - \"%s\" has been requested by %10.10s", reflector->m_id.c_str(), reflector->m_name.c_str(), buffer + 14U);

							m_ysfNetwork->setDestination(reflector->m_address, reflector->m_port);
							m_ysfNetwork->writePoll();
							m_ysfNetwork->writePoll();
							m_ysfNetwork->writePoll();

							inactivityTimer.start();
							lostTimer.start();
							pollTimer.start();

							m_linked = true;
						}
					}
					break;
					case WXS_DISCONNECT:
						if (m_linked) {
							m_wiresX->processDisconnect();

							LogMessage("Disconnect via DTMF has been requested by %10.10s", buffer + 14U);

							m_ysfNetwork->writeUnlink();
							m_ysfNetwork->writeUnlink();
							m_ysfNetwork->writeUnlink();
							m_ysfNetwork->clearDestination();

							inactivityTimer.stop();
							lostTimer.stop();
							pollTimer.stop();

							m_linked = false;
						}
						break;
					default:
						break;
					}
				}

				if (m_gps != NULL)
					m_gps->data(buffer + 14U, buffer + 35U, fi, dt, fn, ft);
			}

			if (networkEnabled && m_linked && !m_exclude) {
				m_ysfNetwork->write(buffer);
				if (::memcmp(buffer + 0U, "YSFD", 4U) == 0)
					inactivityTimer.start();
			}

			if ((buffer[34U] & 0x01U) == 0x01U) {
				if (m_gps != NULL)
					m_gps->reset();
				if (m_dtmf != NULL)
					m_dtmf->reset();
				m_exclude = false;
			}
		}

		while (m_ysfNetwork->read(buffer) > 0U) {
			if (networkEnabled && m_linked) {
				// Only pass through YSF data packets
				if (::memcmp(buffer + 0U, "YSFD", 4U) == 0)
					rptNetwork.write(buffer);

				lostTimer.start();
			}
		}

		unsigned int ms = stopWatch.elapsed();
		stopWatch.start();

		rptNetwork.clock(ms);
		m_ysfNetwork->clock(ms);
		if (m_gps != NULL)
			m_gps->clock(ms);
		if (m_wiresX != NULL)
			m_wiresX->clock(ms);

		inactivityTimer.clock(ms);
		if (inactivityTimer.isRunning() && inactivityTimer.hasExpired()) {
			if (m_linked) {
				CYSFReflector* reflector = NULL;
				if (revert && !startup.empty() && m_wiresX != NULL)
					reflector = m_wiresX->getReflector(startup);

				if (reflector != NULL) {
					LogMessage("Reverting connection to %5.5s - \"%s\"", reflector->m_id.c_str(), reflector->m_name.c_str());

					m_wiresX->processConnect(reflector);

					m_ysfNetwork->writeUnlink();
					m_ysfNetwork->writeUnlink();
					m_ysfNetwork->writeUnlink();

					m_ysfNetwork->setDestination(reflector->m_address, reflector->m_port);
					m_ysfNetwork->writePoll();
					m_ysfNetwork->writePoll();
					m_ysfNetwork->writePoll();

					lostTimer.start();
					pollTimer.start();
				} else {
					LogMessage("Disconnecting due to inactivity");

					if (m_wiresX != NULL)
						m_wiresX->processDisconnect();

					m_ysfNetwork->writeUnlink();
					m_ysfNetwork->writeUnlink();
					m_ysfNetwork->writeUnlink();
					m_ysfNetwork->clearDestination();

					lostTimer.stop();
					pollTimer.stop();

					m_linked = false;
				}
			}

			inactivityTimer.stop();
		}

		lostTimer.clock(ms);
		if (lostTimer.isRunning() && lostTimer.hasExpired()) {
			LogWarning("Link has failed, polls lost");

			if (m_wiresX != NULL)
				m_wiresX->processDisconnect();

			m_ysfNetwork->clearDestination();

			inactivityTimer.stop();
			lostTimer.stop();
			pollTimer.stop();

			m_linked = false;
		}

		pollTimer.clock(ms);
		if (pollTimer.isRunning() && pollTimer.hasExpired()) {
			m_ysfNetwork->writePoll();
			pollTimer.start();
		}

		if (ms < 5U)
			CThread::sleep(5U);
	}

	rptNetwork.close();
	m_ysfNetwork->close();

	if (m_gps != NULL) {
		m_gps->close();
		delete m_gps;
	}

	delete m_ysfNetwork;
	delete m_wiresX;
	delete m_dtmf;

	::LogFinalise();

	return 0;
}

void CYSFGateway::createGPS()
{
	if (!m_conf.getAPRSEnabled())
		return;

	std::string hostname = m_conf.getAPRSServer();
	unsigned int port    = m_conf.getAPRSPort();
	std::string password = m_conf.getAPRSPassword();
	std::string desc     = m_conf.getAPRSDescription();

	m_gps = new CGPS(m_callsign, m_suffix, password, hostname, port);

	unsigned int txFrequency = m_conf.getTxFrequency();
	unsigned int rxFrequency = m_conf.getRxFrequency();
	float latitude           = m_conf.getLatitude();
	float longitude          = m_conf.getLongitude();
	int height               = m_conf.getHeight();

	m_gps->setInfo(txFrequency, rxFrequency, latitude, longitude, height, desc);

	bool ret = m_gps->open();
	if (!ret) {
		delete m_gps;
		m_gps = NULL;
	}
}