/*
 *   Copyright (C) 2015 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 "HomebrewDMRIPSC.h"
#include "StopWatch.h"
#include "SHA256.h"
#include "Utils.h"
#include "Log.h"

#include <cassert>

const unsigned int BUFFER_LENGTH = 500U;

const unsigned int HOMEBREW_DATA_PACKET_LENGTH = 53U;


CHomebrewDMRIPSC::CHomebrewDMRIPSC(const std::string& address, unsigned int port, unsigned int id, const std::string& password, const char* software, const char* version, bool debug) :
m_address(),
m_port(port),
m_id(NULL),
m_password(password),
m_debug(debug),
m_software(software),
m_version(version),
m_socket(),
m_status(DISCONNECTED),
m_retryTimer(1000U, 10U),
m_timeoutTimer(1000U, 600U),
m_pingTimer(1000U, 5U),
m_buffer(NULL),
m_salt(NULL),
m_streamId(NULL),
m_rxData(1000U),
m_callsign(),
m_rxFrequency(0U),
m_txFrequency(0U),
m_power(0U),
m_colorCode(0U),
m_latitude(0.0F),
m_longitude(0.0F),
m_height(0),
m_location(),
m_description(),
m_url(),
m_beacon(false)
{
	assert(!address.empty());
	assert(port > 0U);
	assert(id > 1000U);
	assert(!password.empty());

	m_address = CUDPSocket::lookup(address);

	m_buffer   = new unsigned char[BUFFER_LENGTH];
	m_salt     = new unsigned char[sizeof(uint32_t)];
	m_id       = new uint8_t[4U];
	m_streamId = new uint32_t[2U];

	m_streamId[0U] = 0x00U;
	m_streamId[1U] = 0x00U;

	m_id[0U] = id >> 24;
	m_id[1U] = id >> 16;
	m_id[2U] = id >> 8;
	m_id[3U] = id >> 0;

	CStopWatch stopWatch;
	::srand(stopWatch.start());
}

CHomebrewDMRIPSC::~CHomebrewDMRIPSC()
{
	delete[] m_buffer;
	delete[] m_salt;
	delete[] m_streamId;
	delete[] m_id;
}

void CHomebrewDMRIPSC::setConfig(const std::string& callsign, unsigned int rxFrequency, unsigned int txFrequency, unsigned int power, unsigned int colorCode, float latitude, float longitude, int height, const std::string& location, const std::string& description, const std::string& url)
{
	m_callsign    = callsign;
	m_rxFrequency = rxFrequency;
	m_txFrequency = txFrequency;
	m_power       = power;
	m_colorCode   = colorCode;
	m_latitude    = latitude;
	m_longitude   = longitude;
	m_height      = height;
	m_location    = location;
	m_description = description;
	m_url         = url;
}

bool CHomebrewDMRIPSC::open()
{
	LogMessage("Opening DMR IPSC");

	bool ret = m_socket.open();
	if (!ret)
		return false;

	ret = writeLogin();
	if (!ret) {
		m_socket.close();
		return false;
	}

	m_status = WAITING_LOGIN;
	m_timeoutTimer.start();
	m_retryTimer.start();

	return true;
}

bool CHomebrewDMRIPSC::read(CDMRData& data)
{
	if (m_status != RUNNING)
		return false;

	if (m_rxData.isEmpty())
		return false;

	unsigned char length = 0U;

	m_rxData.getData(&length, 1U);
	m_rxData.getData(m_buffer, length);

	// Is this a data packet?
	if (::memcmp(m_buffer, "DMRD", 4U) != 0)
		return false;

	unsigned char seqNo = m_buffer[4U];

	unsigned int srcId = (m_buffer[5U] << 16) | (m_buffer[6U] << 8) | (m_buffer[7U] << 0);

	unsigned int dstId = (m_buffer[8U] << 16) | (m_buffer[9U] << 8) | (m_buffer[10U] << 0);

	unsigned int slotNo = (m_buffer[15U] & 0x80U) == 0x80U ? 2U : 1U;

	FLCO flco = (m_buffer[15U] & 0x40U) == 0x40U ? FLCO_USER_USER : FLCO_GROUP;

	data.setSeqNo(seqNo);
	data.setSlotNo(slotNo);
	data.setSrcId(srcId);
	data.setDstId(dstId);
	data.setFLCO(flco);

	bool dataSync = (m_buffer[15U] & 0x20U) == 0x20U;
	bool voiceSync = (m_buffer[15U] & 0x10U) == 0x10U;

	if (dataSync) {
		unsigned char dataType = m_buffer[15U] & 0x0FU;
		data.setData(m_buffer + 20U);
		data.setDataType(dataType);
		data.setN(0U);
	} else if (voiceSync) {
		data.setData(m_buffer + 20U);
		data.setDataType(DT_VOICE_SYNC);
		data.setN(0U);
	} else {
		unsigned char n = m_buffer[15U] & 0x0FU;
		data.setData(m_buffer + 20U);
		data.setDataType(DT_VOICE);
		data.setN(n);
	}

	return true;
}

bool CHomebrewDMRIPSC::write(const CDMRData& data)
{
	if (m_status != RUNNING)
		return false;

	unsigned char buffer[HOMEBREW_DATA_PACKET_LENGTH];
	::memset(buffer, 0x00U, HOMEBREW_DATA_PACKET_LENGTH);

	buffer[0U]  = 'D';
	buffer[1U]  = 'M';
	buffer[2U]  = 'R';
	buffer[3U]  = 'D';

	unsigned int srcId = data.getSrcId();
	buffer[5U]  = srcId >> 16;
	buffer[6U]  = srcId >> 8;
	buffer[7U]  = srcId >> 0;

	unsigned int dstId = data.getDstId();
	buffer[8U]  = dstId >> 16;
	buffer[9U]  = dstId >> 8;
	buffer[10U] = dstId >> 0;

	::memcpy(buffer + 11U, m_id, 4U);

	unsigned int slotNo = data.getSlotNo();
	buffer[15U] = slotNo == 1U ? 0x00U : 0x80U;

	FLCO flco = data.getFLCO();
	buffer[15U] |= flco == FLCO_GROUP ? 0x00U : 0x40U;

	unsigned int slotIndex = slotNo - 1U;

	unsigned char dataType = data.getDataType();
	if (dataType == DT_VOICE_SYNC) {
		buffer[15U] |= 0x10U;
	} else if (dataType == DT_VOICE) {
		buffer[15U] |= data.getN();
	} else {
		if ((dataType == DT_VOICE_LC_HEADER || dataType == DT_DATA_HEADER) && data.getSeqNo() == 0U)
			m_streamId[slotIndex] = ::rand() + 1U;

		buffer[15U] |= (0x20U | dataType);
	}

	buffer[4U] = data.getSeqNo();

	::memcpy(buffer + 16U, m_streamId + slotIndex, 4U);

	data.getData(buffer + 20U);

	return write(buffer, HOMEBREW_DATA_PACKET_LENGTH);
}

void CHomebrewDMRIPSC::close()
{
	LogMessage("Closing DMR IPSC");

	unsigned char buffer[9U];
	::memcpy(buffer + 0U, "RPTCL", 5U);
	::memcpy(buffer + 5U, m_id, 4U);
	write(buffer, 9U);

	m_socket.close();
}

void CHomebrewDMRIPSC::clock(unsigned int ms)
{
	in_addr address;
	unsigned int port;
	int length = m_socket.read(m_buffer, BUFFER_LENGTH, address, port);

	if (m_debug && length > 0)
		CUtils::dump(1U, "IPSC Received", m_buffer, length);

	if (length > 0 && m_address.s_addr == address.s_addr && m_port == port) {
		if (::memcmp(m_buffer, "DMRD", 4U) == 0) {
			unsigned char len = length;
			m_rxData.addData(&len, 1U);
			m_rxData.addData(m_buffer, len);
		} else if (::memcmp(m_buffer, "MSTNAK",  6U) == 0) {
			LogError("Login to the master has failed");
			m_status = DISCONNECTED;		// XXX
			m_timeoutTimer.stop();
			m_retryTimer.stop();
		} else if (::memcmp(m_buffer, "RPTACK",  6U) == 0) {
			switch (m_status) {
				case WAITING_LOGIN:
					::memcpy(m_salt, m_buffer + 6U, sizeof(uint32_t));  
					writeAuthorisation();
					m_status = WAITING_AUTHORISATION;
					m_timeoutTimer.start();
					m_retryTimer.start();
					break;
				case WAITING_AUTHORISATION:
					writeConfig();
					m_status = WAITING_CONFIG;
					m_timeoutTimer.start();
					m_retryTimer.start();
					break;
				case WAITING_CONFIG:
					LogMessage("Logged into the master succesfully");
					m_status = RUNNING;
					m_timeoutTimer.start();
					m_retryTimer.stop();
					m_pingTimer.start();
					break;
				default:
					break;
			}
		} else if (::memcmp(m_buffer, "MSTCL",   5U) == 0) {
			LogError("Master is closing down");
			m_status = DISCONNECTED;		// XXX
			m_timeoutTimer.stop();
			m_retryTimer.stop();
		} else if (::memcmp(m_buffer, "MSTPONG", 7U) == 0) {
			m_timeoutTimer.start();
		} else if (::memcmp(m_buffer, "RPTSBKN", 7U) == 0) {
			m_beacon = true;
		} else {
			CUtils::dump("Unknown packet from the master", m_buffer, length);
		}
	}

	if (m_status != RUNNING) {
		m_retryTimer.clock(ms);
		if (m_retryTimer.isRunning() && m_retryTimer.hasExpired()) {
			switch (m_status) {
				case WAITING_LOGIN:
					writeLogin();
					break;
				case WAITING_AUTHORISATION:
					writeAuthorisation();
					break;
				case WAITING_CONFIG:
					writeConfig();
					break;
				default:
					break;
			}

			m_retryTimer.start();
		}
	} else {
		m_pingTimer.clock(ms);
		if (m_pingTimer.isRunning() && m_pingTimer.hasExpired()) {
			writePing();
			m_pingTimer.start();
		}
	}

	m_timeoutTimer.clock(ms);
	if (m_timeoutTimer.isRunning() && m_timeoutTimer.hasExpired()) {
		LogError("Connection to the master has timed out");
		m_status = DISCONNECTED;
		m_timeoutTimer.stop();
		m_retryTimer.stop();
	}
}

bool CHomebrewDMRIPSC::writeLogin()
{
	unsigned char buffer[8U];

	::memcpy(buffer + 0U, "RPTL", 4U);
	::memcpy(buffer + 4U, m_id, 4U);

	return write(buffer, 8U);
}

bool CHomebrewDMRIPSC::writeAuthorisation()
{
	unsigned int size = m_password.size();

	unsigned char* in = new unsigned char[size + sizeof(uint32_t)];
	::memcpy(in, m_salt, sizeof(uint32_t));
	for (unsigned int i = 0U; i < size; i++)
		in[i + sizeof(uint32_t)] = m_password.at(i);

	unsigned char out[40U];
	::memcpy(out + 0U, "RPTK", 4U);
	::memcpy(out + 4U, m_id, 4U);

	CSHA256 sha256;
	sha256.buffer(in, size + sizeof(uint32_t), out + 8U);

	delete[] in;

	return write(out, 40U);
}

bool CHomebrewDMRIPSC::writeConfig()
{
	char buffer[400U];

	::memcpy(buffer + 0U, "RPTC", 4U);
	::memcpy(buffer + 4U, m_id, 4U);

	::sprintf(buffer + 8U, "%-8.8s%09u%09u%02u%02u%-08f%-09f%03d%-20.20s%-20.20s%-124.124s%-40.40s%-40.40s", m_callsign.c_str(),
		m_rxFrequency, m_txFrequency, m_power, m_colorCode, m_latitude, m_longitude, m_height, m_location.c_str(),
		m_description.c_str(), m_url.c_str(), m_software, m_version);

	return write((unsigned char*)buffer, 302U);
}

bool CHomebrewDMRIPSC::writePing()
{
	unsigned char buffer[11U];

	::memcpy(buffer + 0U, "RPTPING", 7U);
	::memcpy(buffer + 7U, m_id, 4U);

	return write(buffer, 11U);
}

bool CHomebrewDMRIPSC::wantsBeacon()
{
	bool beacon = m_beacon;

	m_beacon = false;

	return beacon;
}

bool CHomebrewDMRIPSC::write(const unsigned char* data, unsigned int length)
{
	assert(data != NULL);
	assert(length > 0U);

	if (m_debug)
		CUtils::dump(1U, "IPSC Transmitted", data, length);

	return m_socket.write(data, length, m_address, m_port);
}