/*
 *   Copyright (C) 2010-2014 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.
 */

#ifndef	GMSKModem_H
#define	GMSKModem_H

#include "Utils.h"

/*
 * IGMSKModem - Abstract interface for GMSK modem hardware.
 *
 * Implemented by CGMSKModemLibUsb (libusb) and potentially other backends.
 * CGMSKController owns an IGMSKModem* and drives it through this interface,
 * so the controller is independent of the USB transport details.
 *
 * The interface divides into three functional groups:
 *   Lifecycle: open(), close()
 *   Receive:   readHeader(), readData() - poll-based; called from controller loop
 *   Transmit:  writeHeader(), writeData(), setPTT() - push-based from controller
 *   Status:    getPTT(), hasSpace() - return TRISTATE (TRUE/FALSE/UNKNOWN)
 *              UNKNOWN indicates a hardware error requiring modem reconnection.
 */
class IGMSKModem {
public:
	virtual ~IGMSKModem() = 0;

	virtual bool open() = 0;

	virtual bool readHeader(unsigned char* header, unsigned int length) = 0;
	virtual int  readData(unsigned char* data, unsigned int length, bool& end) = 0;

	virtual TRISTATE getPTT() = 0;
	virtual void     setPTT(bool on) = 0;

	virtual TRISTATE hasSpace() = 0;

	virtual void writeHeader(unsigned char* data, unsigned int length) = 0;
	virtual int  writeData(unsigned char* data, unsigned int length) = 0;

	virtual void close() = 0;

private:
};

#endif