/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/**
 * Copyright (c) 2014-2015,  Regents of the University of California,
 *                           Arizona Board of Regents,
 *                           Colorado State University,
 *                           University Pierre & Marie Curie, Sorbonne University,
 *                           Washington University in St. Louis,
 *                           Beijing Institute of Technology,
 *                           The University of Memphis.
 *
 * This file is part of NFD (Named Data Networking Forwarding Daemon).
 * See AUTHORS.md for complete list of NFD authors and contributors.
 *
 * NFD 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 3 of the License, or (at your option) any later version.
 *
 * NFD 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
 * NFD, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "pit.hpp"
#include <type_traits>

#include <boost/concept/assert.hpp>
#include <boost/concept_check.hpp>
#include <type_traits>

namespace nfd {
namespace pit {

#if HAVE_IS_MOVE_CONSTRUCTIBLE
static_assert(std::is_move_constructible<DataMatchResult>::value,
              "DataMatchResult must be MoveConstructible");
#endif // HAVE_IS_MOVE_CONSTRUCTIBLE

} // namespace pit

// http://en.cppreference.com/w/cpp/concept/ForwardIterator
BOOST_CONCEPT_ASSERT((boost::ForwardIterator<Pit::const_iterator>));
// boost::ForwardIterator follows SGI standard http://www.sgi.com/tech/stl/ForwardIterator.html,
// which doesn't require DefaultConstructible
#ifdef HAVE_IS_DEFAULT_CONSTRUCTIBLE
static_assert(std::is_default_constructible<Pit::const_iterator>::value,
              "Pit::const_iterator must be default-constructible");
#else
BOOST_CONCEPT_ASSERT((boost::DefaultConstructible<Pit::const_iterator>));
#endif // HAVE_IS_DEFAULT_CONSTRUCTIBLE

Pit::Pit(NameTree& nameTree)
  : m_nameTree(nameTree)
  , m_nItems(0)
{
}

Pit::~Pit()
{
}

std::pair<shared_ptr<pit::Entry>, bool>
Pit::findOrInsert(const Interest& interest, bool allowInsert)
{
  // first lookup() the Interest Name in the NameTree, which will creates all
  // the intermedia nodes, starting from the shortest prefix.
  shared_ptr<name_tree::Entry> nameTreeEntry = m_nameTree.lookup(interest.getName());
  BOOST_ASSERT(static_cast<bool>(nameTreeEntry));

  const std::vector<shared_ptr<pit::Entry>>& pitEntries = nameTreeEntry->getPitEntries();

  // then check if this Interest is already in the PIT entries
  auto it = std::find_if(pitEntries.begin(), pitEntries.end(),
                         [&interest] (const shared_ptr<pit::Entry>& entry) {
                           return entry->getInterest().getName() == interest.getName() &&
                                  entry->getInterest().getSelectors() == interest.getSelectors();
                         });
  if (it != pitEntries.end()) {
    return {*it, false};
  }

  if (!allowInsert) {
    return {nullptr, true};
  }

  shared_ptr<pit::Entry> entry = make_shared<pit::Entry>(interest);
  nameTreeEntry->insertPitEntry(entry);
  m_nItems++;
  return {entry, true};
}

pit::DataMatchResult
Pit::findAllDataMatches(const Data& data) const
{
  auto&& ntMatches = m_nameTree.findAllMatches(data.getName(),
    [] (const name_tree::Entry& entry) { return entry.hasPitEntries(); });

  pit::DataMatchResult matches;
  for (const name_tree::Entry& nte : ntMatches) {
    for (const shared_ptr<pit::Entry>& pitEntry : nte.getPitEntries()) {
      if (pitEntry->getInterest().matchesData(data))
        matches.emplace_back(pitEntry);
    }
  }

  return matches;
}

void
Pit::erase(shared_ptr<pit::Entry> pitEntry)
{
  shared_ptr<name_tree::Entry> nameTreeEntry = m_nameTree.get(*pitEntry);
  BOOST_ASSERT(static_cast<bool>(nameTreeEntry));

  nameTreeEntry->erasePitEntry(pitEntry);
  m_nameTree.eraseEntryIfEmpty(nameTreeEntry);

  --m_nItems;
}

Pit::const_iterator
Pit::begin() const
{
  return const_iterator(m_nameTree.fullEnumerate(
    [] (const name_tree::Entry& entry) { return entry.hasPitEntries(); }).begin());
}

} // namespace nfd