/*
 * Copyright (c) 2011 Bucknell University
 *
 * 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
 *
 * Authors: L. Felipe Perrone (perrone@bucknell.edu)
 *          Tiago G. Rodrigues (tgr002@bucknell.edu)
 *
 * Modified by: Mitch Watrous (watrous@u.washington.edu)
 */

#ifndef TIME_PROBE_H
#define TIME_PROBE_H

#include "ns3/boolean.h"
#include "ns3/callback.h"
#include "ns3/nstime.h"
#include "ns3/object.h"
#include "ns3/probe.h"
#include "ns3/simulator.h"
#include "ns3/traced-value.h"

namespace ns3
{

/**
 * \ingroup probes
 *
 * This class is designed to probe an underlying ns3 TraceSource exporting
 * an ns3::Time.  This probe exports a trace source "Output" of type
 * double, in units of seconds. The Output trace source emits a value when
 * either the trace source emits a new value, or when SetValue () is called.
 *
 * The current value of the probe can be polled with the GetValue ()
 * method.
 */
class TimeProbe : public Probe
{
  public:
    /**
     * \brief Get the type ID.
     * \return the object TypeId
     */
    static TypeId GetTypeId();
    TimeProbe();
    ~TimeProbe() override;

    /**
     * \return the most recent value (units of seconds)
     */
    double GetValue() const;

    /**
     * \param value set the traced Time to a new value
     */
    void SetValue(Time value);

    /**
     * \brief Set a probe value by its name in the Config system
     *
     * \param path Config path to access the probe
     * \param value set the traced Time to a new value
     */
    static void SetValueByPath(std::string path, Time value);

    /**
     * \brief connect to a trace source attribute provided by a given object
     *
     * \param traceSource the name of the attribute TraceSource to connect to
     * \param obj ns3::Object to connect to
     * \return true if the trace source was successfully connected
     */
    bool ConnectByObject(std::string traceSource, Ptr<Object> obj) override;

    /**
     * \brief connect to a trace source provided by a config path
     *
     * \param path Config path to bind to
     *
     * Note, if an invalid path is provided, the probe will not be connected
     * to anything.
     */
    void ConnectByPath(std::string path) override;

  private:
    /**
     * \brief Method to connect to an underlying ns3::TraceSource of type Time
     *
     * \param oldData previous value of the Time
     * \param newData new value of the Time
     */
    void TraceSink(Time oldData, Time newData);

    TracedValue<double> m_output; //!< Output trace source.
};

} // namespace ns3

#endif // TIME_PROBE_H
