/*
*   Copyright (C) 2016 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 "P25Control.h"
#include "P25Defines.h"
#include "P25Utils.h"
#include "Utils.h"
#include "Sync.h"
#include "Log.h"

#include <cassert>
#include <ctime>

// #define	DUMP_P25

const unsigned char BIT_MASK_TABLE[] = {0x80U, 0x40U, 0x20U, 0x10U, 0x08U, 0x04U, 0x02U, 0x01U};

#define WRITE_BIT(p,i,b) p[(i)>>3] = (b) ? (p[(i)>>3] | BIT_MASK_TABLE[(i)&7]) : (p[(i)>>3] & ~BIT_MASK_TABLE[(i)&7])
#define READ_BIT(p,i)    (p[(i)>>3] & BIT_MASK_TABLE[(i)&7])

CP25Control::CP25Control(unsigned int nac, CP25Network* network, CDisplay* display, unsigned int timeout, bool duplex, CDMRLookup* lookup, int rssiMultiplier, int rssiOffset) :
m_nac(nac),
m_network(network),
m_display(display),
m_duplex(duplex),
m_lookup(lookup),
m_rssiMultiplier(rssiMultiplier),
m_rssiOffset(rssiOffset),
m_queue(1000U, "P25 Control"),
m_rfState(RS_RF_LISTENING),
m_netState(RS_NET_IDLE),
m_rfTimeout(1000U, timeout),
m_netTimeout(1000U, timeout),
m_networkWatchdog(1000U, 0U, 1500U),
m_rfFrames(0U),
m_rfBits(0U),
m_rfErrs(0U),
m_netFrames(0U),
m_netLost(0U),
m_nid(nac),
m_lastDUID(P25_DUID_TERM),
m_audio(),
m_rfData(),
m_netData(),
m_lsd(),
m_netLDU1(NULL),
m_netLDU2(NULL),
m_fp(NULL)
{
	assert(display != NULL);
	assert(lookup != NULL);

	m_netLDU1 = new unsigned char[9U * 25U];
	m_netLDU2 = new unsigned char[9U * 25U];
}

CP25Control::~CP25Control()
{
	delete[] m_netLDU1;
	delete[] m_netLDU2;
}

bool CP25Control::writeModem(unsigned char* data, unsigned int len)
{
	assert(data != NULL);

	// CUtils::dump(1U, "P25 Data", data, len);

	bool sync = data[1U] == 0x01U;

	if (data[0U] == TAG_LOST && m_rfState == RS_RF_LISTENING)
		return false;

	if (data[0U] == TAG_LOST) {
		LogMessage("P25, transmission lost, %.1f seconds, BER: %.1f%%", float(m_rfFrames) / 5.56F, float(m_rfErrs * 100U) / float(m_rfBits));
		if (m_netState == RS_NET_IDLE)
			m_display->clearP25();
		writeNetwork(data + 2U, P25_DUID_TERM);
		m_rfState = RS_RF_LISTENING;
		m_rfTimeout.stop();
		m_rfData.reset();
#if defined(DUMP_P25)
		closeFile();
#endif
		return false;
	}

	if (!sync && m_rfState == RS_RF_LISTENING)
		return false;

	// Decode the NID
	bool valid = m_nid.decode(data + 2U);

	if (m_rfState == RS_RF_LISTENING && !valid)
		return false;

	unsigned char duid = m_nid.getDUID();
	if (!valid) {
		switch (m_lastDUID) {
		case P25_DUID_HEADER:
		case P25_DUID_LDU2:
			duid = P25_DUID_LDU1;
			break;
		case P25_DUID_LDU1:
			duid = P25_DUID_LDU2;
			break;
		default:
			break;
		}
	}

	if (duid == P25_DUID_HEADER) {
		m_rfData.reset();

		// Regenerate Sync
		CSync::addP25Sync(data + 2U);

		// Regenerate NID
		m_nid.encode(data + 2U, P25_DUID_HEADER);

		// Add the dummy header
		m_netData.createHeader(data + 2U);

		// Add busy bits
		addBusyBits(data + 2U, P25_HDR_FRAME_LENGTH_BITS, false, true);

		m_rfFrames = 0U;
		m_rfErrs   = 0U;
		m_rfBits   = 1U;
		m_rfTimeout.start();
		m_lastDUID = duid;

#if defined(DUMP_P25)
		openFile();
		writeFile(data + 2U, len - 2U);
#endif

		writeNetwork(data + 2U, P25_DUID_HEADER);

		if (m_duplex) {
			data[0U] = TAG_HEADER;
			data[1U] = 0x00U;
			writeQueueRF(data, P25_HDR_FRAME_LENGTH_BYTES + 2U);
		}
	} else if (duid == P25_DUID_LDU1) {
		if (m_rfState == RS_RF_LISTENING) {
			m_rfFrames = 0U;
			m_rfErrs   = 0U;
			m_rfBits   = 1U;
			m_rfTimeout.start();
#if defined(DUMP_P25)
			openFile();
#endif
		}

		// Regenerate Sync
		CSync::addP25Sync(data + 2U);

		// Regenerate NID
		m_nid.encode(data + 2U, P25_DUID_LDU1);

		// Regenerate LDU1 Data
		m_rfData.processLDU1(data + 2U);

		// Regenerate the Low Speed Data
		m_lsd.process(data + 2U);

		// Regenerate Audio
		unsigned int errors = m_audio.process(data + 2U);
		LogDebug("P25, LDU1 audio, errs: %u/1233", errors);

		m_rfBits += 1233U;
		m_rfErrs += errors;
		m_rfFrames++;
		m_lastDUID = duid;

		// Add busy bits
		addBusyBits(data + 2U, P25_LDU_FRAME_LENGTH_BITS, false, true);

#if defined(DUMP_P25)
		writeFile(data + 2U, len - 2U);
#endif

		writeNetwork(data + 2U, P25_DUID_LDU1);

		if (m_duplex) {
			data[0U] = TAG_DATA;
			data[1U] = 0x00U;
			writeQueueRF(data, P25_LDU_FRAME_LENGTH_BYTES + 2U);
		}

		if (m_rfState == RS_RF_LISTENING) {
			unsigned int src = m_rfData.getSource();
			bool         grp = m_rfData.getGroup();
			unsigned int dst = m_rfData.getDest();
			std::string source = m_lookup->find(src);
			LogMessage("P25, received RF transmission from %s to %s%u", source.c_str(), grp ? "TG " : "", dst);
			m_display->writeP25(source.c_str(), grp, dst, "R");
			m_rfState = RS_RF_AUDIO;
		}
	} else if (duid == P25_DUID_LDU2) {
		if (m_rfState == RS_RF_LISTENING)
			return false;

		// Regenerate Sync
		CSync::addP25Sync(data + 2U);

		// Regenerate NID
		m_nid.encode(data + 2U, P25_DUID_LDU2);

		// Add the dummy LDU2 data
		m_netData.createLDU2(data + 2U);

		// Regenerate the Low Speed Data
		m_lsd.process(data + 2U);

		// Regenerate Audio
		unsigned int errors = m_audio.process(data + 2U);
		LogDebug("P25, LDU2 audio, errs: %u/1233", errors);

		m_rfBits += 1233U;
		m_rfErrs += errors;
		m_rfFrames++;
		m_lastDUID = duid;

		// Add busy bits
		addBusyBits(data + 2U, P25_LDU_FRAME_LENGTH_BITS, false, true);

#if defined(DUMP_P25)
		writeFile(data + 2U, len - 2U);
#endif

		writeNetwork(data + 2U, P25_DUID_LDU2);

		if (m_duplex) {
			data[0U] = TAG_DATA;
			data[1U] = 0x00U;
			writeQueueRF(data, P25_LDU_FRAME_LENGTH_BYTES + 2U);
		}
	} else if (duid == P25_DUID_TERM_LC) {
		if (m_rfState == RS_RF_LISTENING)
			return false;

		// Regenerate Sync
		CSync::addP25Sync(data + 2U);

		// Regenerate NID
		m_nid.encode(data + 2U, P25_DUID_TERM_LC);

		// Leave the termination LC untouched

		// Add busy bits
		addBusyBits(data + 2U, P25_TERMLC_FRAME_LENGTH_BITS, false, true);

		m_rfState = RS_RF_LISTENING;
		m_rfTimeout.stop();
		m_rfData.reset();
		m_lastDUID = duid;

		LogMessage("P25, received RF end of transmission, %.1f seconds, BER: %.1f%%", float(m_rfFrames) / 5.56F, float(m_rfErrs * 100U) / float(m_rfBits));
		m_display->clearP25();

#if defined(DUMP_P25)
		closeFile();
#endif

		writeNetwork(data + 2U, P25_DUID_TERM_LC);

		if (m_duplex) {
			data[0U] = TAG_EOT;
			data[1U] = 0x00U;
			writeQueueRF(data, P25_TERMLC_FRAME_LENGTH_BYTES + 2U);
		}
	} else if (duid == P25_DUID_TERM) {
		if (m_rfState == RS_RF_LISTENING)
			return false;

		// Regenerate Sync
		CSync::addP25Sync(data + 2U);

		// Regenerate NID
		m_nid.encode(data + 2U, P25_DUID_TERM);

		// Add busy bits
		addBusyBits(data + 2U, P25_TERM_FRAME_LENGTH_BITS, false, true);

		m_rfState = RS_RF_LISTENING;
		m_rfTimeout.stop();
		m_rfData.reset();
		m_lastDUID = duid;

		LogMessage("P25, received RF end of transmission, %.1f seconds, BER: %.1f%%", float(m_rfFrames) / 5.56F, float(m_rfErrs * 100U) / float(m_rfBits));
		m_display->clearP25();

#if defined(DUMP_P25)
		closeFile();
#endif

		writeNetwork(data + 2U, P25_DUID_TERM);

		if (m_duplex) {
			data[0U] = TAG_EOT;
			data[1U] = 0x00U;
			writeQueueRF(data, P25_TERM_FRAME_LENGTH_BYTES + 2U);
		}
	} else {
		return false;
	}

	return true;
}

unsigned int CP25Control::readModem(unsigned char* data)
{
	assert(data != NULL);

	if (m_queue.isEmpty())
		return 0U;

	unsigned char len = 0U;
	m_queue.getData(&len, 1U);

	m_queue.getData(data, len);

	return len;
}

void CP25Control::writeNetwork()
{
	unsigned char data[100U];
	unsigned int length = m_network->read(data, 100U);
	if (length == 0U)
		return;

	if (m_rfState != RS_RF_LISTENING && m_netState == RS_NET_IDLE)
		return;

	m_networkWatchdog.start();

	switch (data[0U]) {
	case 0x62U:
		::memcpy(m_netLDU1 + 0U, data, 22U);
		return;
	case 0x63U:
		::memcpy(m_netLDU1 + 25U, data, 13U);
		return;
	case 0x64U:
		::memcpy(m_netLDU1 + 50U, data, 17U);
		return;
	case 0x65U:
		::memcpy(m_netLDU1 + 75U, data, 17U);
		return;
	case 0x66U:
		::memcpy(m_netLDU1 + 100U, data, 17U);
		return;
	case 0x67U:
		::memcpy(m_netLDU1 + 125U, data, 17U);
		return;
	case 0x68U:
		::memcpy(m_netLDU1 + 150U, data, 17U);
		return;
	case 0x69U:
		::memcpy(m_netLDU1 + 175U, data, 17U);
		return;
	case 0x6AU:
		::memcpy(m_netLDU1 + 200U, data, 16U);
		if (m_netState != RS_NET_IDLE)
			createLDU1();
		return;
	case 0x6BU:
		::memcpy(m_netLDU2 + 0U, data, 22U);
		return;
	case 0x6CU:
		::memcpy(m_netLDU2 + 25U, data, 13U);
		return;
	case 0x6DU:
		::memcpy(m_netLDU2 + 50U, data, 17U);
		return;
	case 0x6EU:
		::memcpy(m_netLDU2 + 75U, data, 17U);
		return;
	case 0x6FU:
		::memcpy(m_netLDU2 + 100U, data, 17U);
		return;
	case 0x70U:
		::memcpy(m_netLDU2 + 125U, data, 17U);
		return;
	case 0x71U:
		::memcpy(m_netLDU2 + 150U, data, 17U);
		return;
	case 0x72U:
		::memcpy(m_netLDU2 + 175U, data, 17U);
		return;
	case 0x73U:
		::memcpy(m_netLDU2 + 200U, data, 16U);
		if (m_netState != RS_NET_IDLE) {
			createHeader();
			createLDU1();
		}
		createLDU2();
		return;
	case 0x00U:
		createTerminator(data);
		return;
	default:
		return;
	}
}

void CP25Control::clock(unsigned int ms)
{
	if (m_network != NULL)
		writeNetwork();

	m_rfTimeout.clock(ms);
	m_netTimeout.clock(ms);

	if (m_netState == RS_NET_AUDIO) {
		m_networkWatchdog.clock(ms);

		if (m_networkWatchdog.hasExpired()) {
			LogMessage("P25, network watchdog has expired, %.1f seconds, %u%% packet loss", float(m_netFrames) / 5.56F, (m_netLost * 100U) / m_netFrames);
			m_display->clearP25();
			m_networkWatchdog.stop();
			m_netState = RS_NET_IDLE;
			m_netData.reset();
			m_netTimeout.stop();
		}
	}
}

void CP25Control::writeQueueRF(const unsigned char* data, unsigned int length)
{
	assert(data != NULL);

	if (m_rfTimeout.isRunning() && m_rfTimeout.hasExpired())
		return;

	unsigned int space = m_queue.freeSpace();
	if (space < (length + 1U)) {
		LogError("P25, overflow in the P25 RF queue");
		return;
	}

	unsigned char len = length;
	m_queue.addData(&len, 1U);

	m_queue.addData(data, len);
}

void CP25Control::writeQueueNet(const unsigned char* data, unsigned int length)
{
	assert(data != NULL);

	if (m_netTimeout.isRunning() && m_netTimeout.hasExpired())
		return;

	unsigned int space = m_queue.freeSpace();
	if (space < (length + 1U)) {
		LogError("P25, overflow in the P25 RF queue");
		return;
	}

	unsigned char len = length;
	m_queue.addData(&len, 1U);

	m_queue.addData(data, len);
}

void CP25Control::writeNetwork(const unsigned char *data, unsigned char type)
{
	assert(data != NULL);

	if (m_network == NULL)
		return;

	if (m_rfTimeout.isRunning() && m_rfTimeout.hasExpired())
		return;

	switch (type)
	{
	case P25_DUID_LDU1:
		m_network->writeLDU1(data);
		break;
	case P25_DUID_LDU2:
		m_network->writeLDU2(data);
		break;
	case P25_DUID_TERM:
	case P25_DUID_TERM_LC:
		m_network->writeTerminator();
		break;
	default:
		break;
	}
}

void CP25Control::addBusyBits(unsigned char* data, unsigned int length, bool b1, bool b2)
{
	assert(data != NULL);

	for (unsigned int ss0Pos = P25_SS0_START; ss0Pos < length; ss0Pos += P25_SS_INCREMENT) {
		unsigned int ss1Pos = ss0Pos + 1U;
		WRITE_BIT(data, ss0Pos, b1);
		WRITE_BIT(data, ss1Pos, b2);
	}
}

void CP25Control::createHeader()
{
	unsigned char buffer[P25_HDR_FRAME_LENGTH_BYTES + 2U];
	::memset(buffer, 0x00U, P25_HDR_FRAME_LENGTH_BYTES + 2U);

	buffer[0U] = TAG_HEADER;
	buffer[1U] = 0x00U;

	// Add the sync
	CSync::addP25Sync(buffer + 2U);

	// Add the NID
	m_nid.encode(buffer + 2U, P25_DUID_HEADER);

	// Add the dummy header
	m_netData.createHeader(buffer + 2U);

	// Add busy bits
	addBusyBits(buffer + 2U, P25_HDR_FRAME_LENGTH_BITS, false, true);

	writeQueueNet(buffer, P25_HDR_FRAME_LENGTH_BYTES + 2U);

	bool grp = m_netLDU1[51U] == 0x00U;
	unsigned int dst = (m_netLDU1[76U] << 16) + (m_netLDU1[77U] << 8) + m_netLDU1[78U];
	unsigned int src = (m_netLDU1[101U] << 16) + (m_netLDU1[102U] << 8) + m_netLDU1[103U];
	std::string source = m_lookup->find(src);

	LogMessage("P25, received network transmission from %s to %s%u", source.c_str(), grp ? "TG " : "", dst);

	m_display->writeP25(source.c_str(), grp, dst, "N");

	m_netData.setSource(src);
	m_netData.setGroup(grp);
	m_netData.setDest(dst);

	m_netState = RS_NET_AUDIO;
	m_netTimeout.start();
	m_netFrames = 0U;
	m_netLost = 0U;
}

void CP25Control::createLDU1()
{
	unsigned char buffer[P25_LDU_FRAME_LENGTH_BYTES + 2U];
	::memset(buffer, 0x00U, P25_LDU_FRAME_LENGTH_BYTES + 2U);

	buffer[0U] = TAG_DATA;
	buffer[1U] = 0x00U;

	// Add the sync
	CSync::addP25Sync(buffer + 2U);

	// Add the NID
	m_nid.encode(buffer + 2U, P25_DUID_LDU1);

	// Add the LDU1 data
	m_netData.createLDU1(buffer + 2U);

	// Add the Audio
	m_audio.encode(buffer + 2U, m_netLDU1 + 10U, 0U);
	m_audio.encode(buffer + 2U, m_netLDU1 + 26U, 1U);
	m_audio.encode(buffer + 2U, m_netLDU1 + 55U, 2U);
	m_audio.encode(buffer + 2U, m_netLDU1 + 80U, 3U);
	m_audio.encode(buffer + 2U, m_netLDU1 + 105U, 4U);
	m_audio.encode(buffer + 2U, m_netLDU1 + 130U, 5U);
	m_audio.encode(buffer + 2U, m_netLDU1 + 155U, 6U);
	m_audio.encode(buffer + 2U, m_netLDU1 + 180U, 7U);
	m_audio.encode(buffer + 2U, m_netLDU1 + 204U, 8U);

	// Add the Low Speed Data
	m_lsd.encode(buffer + 2U, m_netLDU1[201U], m_netLDU1[202U]);

	// Add busy bits
	addBusyBits(buffer + 2U, P25_LDU_FRAME_LENGTH_BITS, false, true);

	writeQueueNet(buffer, P25_LDU_FRAME_LENGTH_BYTES + 2U);

	m_netFrames++;
}

void CP25Control::createLDU2()
{
	unsigned char buffer[P25_LDU_FRAME_LENGTH_BYTES + 2U];
	::memset(buffer, 0x00U, P25_LDU_FRAME_LENGTH_BYTES + 2U);

	buffer[0U] = TAG_DATA;
	buffer[1U] = 0x00U;

	// Add the sync
	CSync::addP25Sync(buffer + 2U);

	// Add the NID
	m_nid.encode(buffer + 2U, P25_DUID_LDU2);

	// Add the dummy LDU2 data
	m_netData.createLDU2(buffer + 2U);

	// Add the Audio
	m_audio.encode(buffer + 2U, m_netLDU2 + 10U, 0U);
	m_audio.encode(buffer + 2U, m_netLDU2 + 26U, 1U);
	m_audio.encode(buffer + 2U, m_netLDU2 + 55U, 2U);
	m_audio.encode(buffer + 2U, m_netLDU2 + 80U, 3U);
	m_audio.encode(buffer + 2U, m_netLDU2 + 105U, 4U);
	m_audio.encode(buffer + 2U, m_netLDU2 + 130U, 5U);
	m_audio.encode(buffer + 2U, m_netLDU2 + 155U, 6U);
	m_audio.encode(buffer + 2U, m_netLDU2 + 180U, 7U);
	m_audio.encode(buffer + 2U, m_netLDU2 + 204U, 8U);

	// Add the Low Speed Data
	m_lsd.encode(buffer + 2U, m_netLDU2[201U], m_netLDU2[202U]);

	// Add busy bits
	addBusyBits(buffer + 2U, P25_LDU_FRAME_LENGTH_BITS, false, true);

	writeQueueNet(buffer, P25_LDU_FRAME_LENGTH_BYTES + 2U);

	m_netFrames++;
}

void CP25Control::createTerminator(const unsigned char* data)
{
	assert(data != NULL);

	if (data[3U] != 0x25U)
		return;

	unsigned char buffer[P25_TERM_FRAME_LENGTH_BYTES + 2U];
	::memset(buffer, 0x00U, P25_TERMLC_FRAME_LENGTH_BYTES + 2U);

	buffer[0U] = TAG_EOT;
	buffer[1U] = 0x00U;

	// Add the sync
	CSync::addP25Sync(buffer + 2U);

	// Add the NID
	m_nid.encode(buffer + 2U, P25_DUID_TERM);

	// Add busy bits
	addBusyBits(buffer + 2U, P25_TERM_FRAME_LENGTH_BITS, false, true);

	writeQueueNet(buffer, P25_TERM_FRAME_LENGTH_BYTES + 2U);

	LogMessage("P25, network end of transmission, %.1f seconds, %u%% packet loss", float(m_netFrames) / 5.56F, (m_netLost * 100U) / m_netFrames);

	m_display->clearP25();
	m_netTimeout.stop();
	m_networkWatchdog.stop();
	m_netData.reset();
	m_netState = RS_NET_IDLE;
}

bool CP25Control::openFile()
{
	if (m_fp != NULL)
		return true;

	time_t t;
	::time(&t);

	struct tm* tm = ::localtime(&t);

	char name[100U];
	::sprintf(name, "P25_%04d%02d%02d_%02d%02d%02d.ambe", tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday, tm->tm_hour, tm->tm_min, tm->tm_sec);

	m_fp = ::fopen(name, "wb");
	if (m_fp == NULL)
		return false;

	::fwrite("P25", 1U, 3U, m_fp);

	return true;
}

bool CP25Control::writeFile(const unsigned char* data, unsigned char length)
{
	if (m_fp == NULL)
		return false;

	::fwrite(&length, 1U, 1U, m_fp);

	::fwrite(data, 1U, length, m_fp);

	return true;
}

void CP25Control::closeFile()
{
	if (m_fp != NULL) {
		::fclose(m_fp);
		m_fp = NULL;
	}
}