/*
 *   Copyright (C) 2019-2021 by Thomas A. Early N7TAE
 *
 *   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.
 */

#pragma once

#include <cstring>
#include <string>
#include <queue>

#include <netinet/in.h>
#include "Random.h"	// for streamid generation
#include "UnixDgramSocket.h"
#include "QnetTypeDefs.h"
#include "Timer.h"
#include "Base.h"

#define CALL_SIZE 8
#define IP_SIZE 15

enum class EModemResponse
{
	ack,
	nack,
	timeout,
	error,
	header,
	data,
	lost,
	eot,
	status,
	version
};

enum class EHardwareType
{
	mmdvm,
	dvmega,
	zumspot,
	hs_hat,
	hs_dual_hat,
	nano_hs,
	nano_dv,
	mmdvm_hs,
	unknown
};

// Icom Terminal and Access Point Mode data structure
#pragma pack(push, 1)
using SVERSION = struct version_tag
{
	unsigned char start;
	unsigned char length;
	unsigned char type;
	unsigned char protocol;
	unsigned char version[251];
};

using SMODEM = struct mmodem_tag
{
	unsigned char start;	// always 0xEOU
	unsigned char length;	// 3 - 255
	unsigned char type;
	// 0x70U acknowledge from modem, ACK
	// 0x7FU error from modem, NACK
	// 0x00U version
	// 0x01U status
	// 0x02U configure
	// 0x03U mode
	// 0x04U frequency
	// 0x10U header
	// 0x11U data
	// 0x12U transmission lost
	// 0x13U transmission end
	union
	{
		unsigned char ack;			// the type being acknowledged
		unsigned char mode;			// 0 idle, 1 dstar, 2 dmr, 3 ysf, 99 calibration
		struct
		{
			unsigned char ack;		// the type being acknowledged
			unsigned char reason;	// reason for the NAK
			// 1 - invalid command
			// 2 - wrong mode
			// 3 - command too long
			// 4 - data incorrect
			// 5 - Not enough buffer space
		} nack;
		// don't want to inflate the struct size, so it's here for reference only
		//struct {
		//	unsigned char protocol_version;
		//	unsigned char version[250];
		//} version;
		struct
		{
			unsigned char modes;	// 0x1U dstar | 0x2 dmr | 0x4 system fusion
			unsigned char status;	// 0 idle, 1 dstar, 2 dmr, 3 system fusion, 99 calibration
			unsigned char flags;	// 0x1 Tx on, 0x2 adc overflow
			unsigned char dsrsize;	// dstar buffersize
			unsigned char dm1size;	// drm timeslot 1 buffersize
			unsigned char dm2size;	// dmr timeslot 2 buffersize
			unsigned char ysfsize;  // ysf buffersize
		} status;
		struct
		{
			unsigned char flags;		// 0x1 rx 0x2 tx 0x4 ptt 0x8 ysf lodev 0x10 debug 0x80 not duplex
			unsigned char mode;			// 0x1 dstar 0x2 drm 0x4 ysf 0x8 p25 0x10 nxdx 0x20 pocsag
			unsigned char tx_delay;		// tx delay in 10 millisecond increments
			unsigned char init_mode;	// inital state 0 idle 1 dstar 2 dmr 3 ysf 99 calibration
			unsigned char rx_level;		// rx input level 0-255
			unsigned char cw_tx_level;	// cw tx output
			unsigned char color;		// dmr color 0-15
			unsigned char drm_delay;
			unsigned char osc_offset;	// 128U
			unsigned char dstar_tx_level;
			unsigned char dmr_tx_level;
			unsigned char ysf_tx_level;
			unsigned char p25_tx_level;
			unsigned char tx_dc_offset;
			unsigned char rx_dc_offset;
			unsigned char nxdn_tx_level;
			unsigned char ysf_tx_hang;
			unsigned char pocsag_tx;
		} config;
		struct
		{
			unsigned char zero;	// should be zero;
			uint32_t rx;	// receive frequency
			uint32_t tx;	// transmitter frequency
			unsigned char level;	// rf level
			uint32_t ps;	// pocsag frequency, default 433000000U
		} frequency;
		struct
		{
			unsigned char flag[3];
			unsigned char r2[8];
			unsigned char r1[8];
			unsigned char ur[8];
			unsigned char my[8];
			unsigned char nm[4];
			unsigned char pfcs[2];
		} header;
		struct
		{
			unsigned char ambe[9];
			unsigned char text[3];
		} voice;
	};
};
#pragma pack(pop)

class CFrame
{
public:
	CFrame(const unsigned char *buf)
	{
		memcpy(&frame.start, buf, buf[1]);
	}

	CFrame(const CFrame &from)
	{
		memcpy(&frame.start, from.data(), from.size());
	}

	CFrame &operator=(const CFrame &from)
	{
		memcpy(&frame.start, from.data(), from.size());
		return *this;
	}

	~CFrame() {}

	size_t size() const { return (size_t)frame.length; }

	const unsigned char *data() const { return &frame.start; }
	unsigned char type() { return frame.type; }

private:
	SMODEM frame;
};

class CQnetModem : public CModem
{
public:
	// functions
	CQnetModem(int mod) : CModem(mod), dstarSpace(0) {}
	~CQnetModem() {}
	bool Initialize(const std::string &cfgfile);
	void Run();
	void Close();

private:
	unsigned int dstarSpace;

	// functions
	bool VoicePacketIsSync(const unsigned char *);
	void ProcessGateway(const SDSVT &dsvt);
	bool ProcessModem(const SMODEM &frame);
	int OpenModem();
	int SendToModem(const unsigned char *buf);
	EModemResponse GetModemData(unsigned char *buf, unsigned int size);
	bool GetVersion();
	bool GetBufferSize();
	bool SetFrequency();
	bool SetConfiguration();

	// read configuration file
	bool ReadConfig(const std::string &path);

	// config data
	char RPTR_MOD;
	std::string MODEM_DEVICE, RPTR;
	double TX_FREQUENCY, RX_FREQUENCY, TX_OFFSET, RX_OFFSET, packet_wait;
	int TX_DELAY, RX_LEVEL, TX_LEVEL, RF_LEVEL, PACKET_WAIT;
	bool DUPLEX, RX_INVERT, TX_INVERT, PTT_INVERT, LOG_QSO, LOG_DEBUG;

	// parameters
	EHardwareType hardwareType;
	int serfd;


	// helpers
	CRandom random;
	CTimer PacketWait;

	// unix sockets
	CUnixDgramWriter ToGate;
	CUnixDgramReader FromGate;

	// Queue
	std::queue<CFrame> queue;
};