/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/**
 * Copyright (c) 2013-2016 Regents of the University of California.
 *
 * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
 *
 * ndn-cxx library is free software: you can redistribute it and/or modify it under the
 * terms of the GNU Lesser General Public License as published by the Free Software
 * Foundation, either version 3 of the License, or (at your option) any later version.
 *
 * ndn-cxx library 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 Lesser General Public License for more details.
 *
 * You should have received copies of the GNU General Public License and GNU Lesser
 * General Public License along with ndn-cxx, e.g., in COPYING.md file.  If not, see
 * <http://www.gnu.org/licenses/>.
 *
 * See AUTHORS.md for complete list of ndn-cxx authors and contributors.
 */

#ifndef NDN_DETAIL_PENDING_INTEREST_HPP
#define NDN_DETAIL_PENDING_INTEREST_HPP

#include "../interest.hpp"
#include "../data.hpp"
#include "../lp/nack.hpp"
#include "../util/scheduler-scoped-event-id.hpp"

namespace ndn {

/**
 * @brief stores a pending Interest and associated callbacks
 */
class PendingInterest : noncopyable
{
public:
  /**
   * @brief Construct a pending Interest record
   *
   * The timeout is set based on the current time and the Interest lifetime.
   * This class will invoke the timeout callback unless the record is deleted before timeout.
   *
   * @param interest the Interest
   * @param dataCallback invoked when matching Data packet is received
   * @param nackCallback invoked when Nack matching Interest is received
   * @param timeoutCallback invoked when Interest times out
   * @param scheduler Scheduler for scheduling the timeout event
   */
  PendingInterest(shared_ptr<const Interest> interest,
                  const DataCallback& dataCallback,
                  const NackCallback& nackCallback,
                  const TimeoutCallback& timeoutCallback,
                  Scheduler& scheduler)
    : m_interest(interest)
    , m_dataCallback(dataCallback)
    , m_nackCallback(nackCallback)
    , m_timeoutCallback(timeoutCallback)
    , m_timeoutEvent(scheduler)
  {
    m_timeoutEvent =
      scheduler.scheduleEvent(m_interest->getInterestLifetime() > time::milliseconds::zero() ?
                              m_interest->getInterestLifetime() :
                              DEFAULT_INTEREST_LIFETIME,
                              [=] { this->invokeTimeoutCallback(); });
  }

  /**
   * @return the Interest
   */
  shared_ptr<const Interest>
  getInterest() const
  {
    return m_interest;
  }

  /**
   * @brief invokes the Data callback
   */
  void
  invokeDataCallback(const Data& data)
  {
    m_dataCallback(*m_interest, data);
  }

  /**
   * @brief invokes the Nack callback
   */
  void
  invokeNackCallback(const lp::Nack& nack)
  {
    m_nackCallback(*m_interest, nack);
  }

  /**
   * @brief Set cleanup function to be invoked when Interest times out
   */
  void
  setDeleter(const std::function<void()>& deleter)
  {
    m_deleter = deleter;
  }

private:
  /**
   * @brief invokes the timeout callback (if non-empty) and the deleter
   */
  void
  invokeTimeoutCallback()
  {
    if (m_timeoutCallback) {
      m_timeoutCallback(*m_interest);
    }

    BOOST_ASSERT(m_deleter);
    m_deleter();
  }

private:
  shared_ptr<const Interest> m_interest;
  DataCallback m_dataCallback;
  NackCallback m_nackCallback;
  TimeoutCallback m_timeoutCallback;
  util::scheduler::ScopedEventId m_timeoutEvent;
  std::function<void()> m_deleter;
};

/**
 * @brief Opaque type to identify a PendingInterest
 */
class PendingInterestId;

/**
 * @brief Functor to match PendingInterestId
 */
class MatchPendingInterestId
{
public:
  explicit
  MatchPendingInterestId(const PendingInterestId* pendingInterestId)
    : m_id(pendingInterestId)
  {
  }

  bool
  operator()(const shared_ptr<const PendingInterest>& pendingInterest) const
  {
    return reinterpret_cast<const PendingInterestId*>(pendingInterest->getInterest().get()) == m_id;
  }

private:
  const PendingInterestId* m_id;
};

} // namespace ndn

#endif // NDN_DETAIL_PENDING_INTEREST_HPP