/*
 *   Copyright (C) 2010-2015 by Jonathan Naylor G4KLX
 *   Copyright (C) 2018-2020 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.
 */

#include <string>
#include <cassert>
#include <cstdio>
#include <cctype>
#include <cstring>
#include <thread>
#include <chrono>
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>

#include "DPlusAuthenticator.h"
#include "Utilities.h"

CDPlusAuthenticator::CDPlusAuthenticator(const std::string &loginCallsign, const std::string &address) :
	m_loginCallsign(loginCallsign),
	m_address(address)
{
	assert(loginCallsign.size());

	trim(m_loginCallsign);
}

CDPlusAuthenticator::~CDPlusAuthenticator()
{
}

int CDPlusAuthenticator::Process(CQnetDB &db, const bool reflectors, const bool repeaters)
// return true if everything went okay
{
	int result = client.Open(m_address, AF_UNSPEC, "20001");
	if (result)
	{
		fprintf(stderr, "DPlus Authorization failed: %s\n", gai_strerror(result));
		return 0;
	}
	return authenticate(db, reflectors, repeaters);
}

int CDPlusAuthenticator::authenticate(CQnetDB &db, const bool reflectors, const bool repeaters)
{
	unsigned char buffer[4096U];
	::memset(buffer, ' ', 56U);

	buffer[0U] = 0x38U;
	buffer[1U] = 0xC0U;
	buffer[2U] = 0x01U;
	buffer[3U] = 0x00U;

	::memcpy(buffer+4, m_loginCallsign.c_str(), m_loginCallsign.size());
	::memcpy(buffer+12, "DV019999", 8);
	::memcpy(buffer+28, "W7IB2", 5);
	::memcpy(buffer+40, "DHS0257", 7);

	if (client.Write(buffer, 56U))
	{
		fprintf(stderr, "ERROR: could not write opening phrase\n");
		client.Close();
		return 0;
	}

	int ret = client.ReadExact(buffer, 2U);
	unsigned int rval = 0;
	CHostQueue hqueue;

	while (ret == 2)
	{
		unsigned int len = (buffer[1U] & 0x0FU) * 256U + buffer[0U];
		// Ensure that we get exactly len - 2U bytes from the TCP stream
		ret = client.ReadExact(buffer + 2U, len - 2U);
		if (0 > ret)
		{
			fprintf(stderr, "Problem reading line, it returned %d\n", errno);
			return rval;
		}

		if ((buffer[1U] & 0xC0U) != 0xC0U || buffer[2U] != 0x01U)
		{
			fprintf(stderr, "Invalid packet received from 20001\n");
			return rval;
		}

		for (unsigned int i = 8U; (i + 25U) < len; i += 26U)
		{
			std::string address((char *)(buffer + i));
			std::string name((char *)(buffer + i + 16U));

			trim(address);
			trim(name);
			name.resize(6, ' ');

			// Get the active flag
			bool active = (buffer[i + 25U] & 0x80U) == 0x80U;

			// An empty name or IP address or an inactive gateway/reflector is not added
			if (address.size()>0U && name.size()>0U && active)
			{
				if (reflectors && 0==name.compare(0, 3, "REF"))
				{
					rval++;
					hqueue.Push(CHost(name.c_str(), address.c_str(), 20001));
				}
				else if (repeaters && name.compare(0, 3, "REF"))
				{
					rval++;
					hqueue.Push(CHost(name.c_str(), address.c_str(), 20001));
				}
			}
		}
		if (! hqueue.Empty())
			db.UpdateGW(hqueue);

		ret = client.ReadExact(buffer, 2U);
	}

	printf("Probably authorized DPlus on %s using callsign %s\n", m_address.c_str(), m_loginCallsign.c_str());
	client.Close();

	return rval;
}