/*
 * Copyright (c) 2020 Lawrence Livermore National Laboratory
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation;
 *
 * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * Author: Peter D. Barnes, Jr. <pdbarnes@llnl.gov>
 */

#include "ns3/assert.h"
#include "ns3/fatal-error.h"
#include "ns3/simulator.h"

#include <iostream>

/**
 * \file
 * \defgroup fatal-example Core example: NS_FATAL error handlers
 * \ingroup core-examples
 * \ingroup fatal
 *
 * Example program illustrating use of the NS_FATAL error handlers.
 */

using namespace ns3;

/**
 * \ingroup fatal-example
 * \brief Triggers a fatal error without message, deferring termination.
 */
void
FatalNoMsg()
{
    std::cerr << "\nEvent triggered fatal error without message, and continuing:" << std::endl;
    NS_FATAL_ERROR_NO_MSG_CONT();
}

/**
 * \ingroup fatal-example
 * \brief Triggers a fatal error with an error message, deferring termination.
 */
void
FatalCont()
{
    std::cerr << "\nEvent triggered fatal error, with custom message, and continuing:" << std::endl;
    NS_FATAL_ERROR_CONT("fatal error, but continuing");
}

/**
 * \ingroup fatal-example
 * \brief Triggers a fatal error with message, and terminating.
 */
void
Fatal()
{
    std::cerr << "\nEvent triggered fatal error, with message, and terminating:" << std::endl;
    NS_FATAL_ERROR("fatal error, terminating");
}

int
main(int argc, char** argv)
{
    // First schedule some events
    Simulator::Schedule(Seconds(1), FatalNoMsg);
    Simulator::Schedule(Seconds(2), FatalCont);
    Simulator::Schedule(Seconds(3), Fatal);

    // Show some errors outside of simulation time
    std::cerr << "\nFatal error with custom message, and continuing:" << std::endl;
    NS_FATAL_ERROR_CONT("fatal error, but continuing");

    std::cerr << "\nFatal error without message, and continuing:" << std::endl;
    NS_FATAL_ERROR_NO_MSG_CONT();

    // Now run the simulator
    Simulator::Run();

    // Should not get here
    NS_FATAL_ERROR("fatal error, terminating");
    NS_ASSERT_MSG(false, "Should not get here.");

    return 0;
}