/* -*- mode: C++; indent-tabs-mode: nil; -*-

 *

 * This file is a part of LEMON, a generic C++ optimization library.

 *

 * Copyright (C) 2003-2009

 * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport

 * (Egervary Research Group on Combinatorial Optimization, EGRES).

 *

 * Permission to use, modify and distribute this software is granted

 * provided that this copyright notice appears in all copies. For

 * precise terms see the accompanying LICENSE file.

 *

 * This software is provided "AS IS" with no warranty of any kind,

 * express or implied, and with no claim as to its suitability for any

 * purpose.

 *

 */

#ifndef LEMON_BITS_VECTOR_MAP_H

#define LEMON_BITS_VECTOR_MAP_H

#include <vector>

#include <algorithm>

#include <lemon/core.h>

#include <lemon/bits/alteration_notifier.h>

#include <lemon/concept_check.h>

#include <lemon/concepts/maps.h>

//\ingroup graphbits

//

//\file

//\brief Vector based graph maps.

namespace lemon {

  // \ingroup graphbits

  //

  // \brief Graph map based on the std::vector storage.

  //

  // The VectorMap template class is graph map structure that automatically

  // updates the map when a key is added to or erased from the graph.

  // This map type uses std::vector to store the values.

  //

  // \tparam _Graph The graph this map is attached to.

  // \tparam _Item The item type of the graph items.

  // \tparam _Value The value type of the map.

  template <typename _Graph, typename _Item, typename _Value>

  class VectorMap

    : public ItemSetTraits<_Graph, _Item>::ItemNotifier::ObserverBase {

  private:

    // The container type of the map.

    typedef std::vector<_Value> Container;

  public:

    // The graph type of the map.

    typedef _Graph Graph;

    // The item type of the map.

    typedef _Item Item;

    // The reference map tag.

    typedef True ReferenceMapTag;

    // The key type of the map.

    typedef _Item Key;

    // The value type of the map.

    typedef _Value Value;

    // The notifier type.

    typedef typename ItemSetTraits<_Graph, _Item>::ItemNotifier Notifier;

    // The map type.

    typedef VectorMap Map;

    // The base class of the map.

    typedef typename Notifier::ObserverBase Parent;

    // The reference type of the map;

    typedef typename Container::reference Reference;

    // The const reference type of the map;

    typedef typename Container::const_reference ConstReference;

    // \brief Constructor to attach the new map into the notifier.

    //

    // It constructs a map and attachs it into the notifier.

    // It adds all the items of the graph to the map.

    VectorMap(const Graph& graph) {

      Parent::attach(graph.notifier(Item()));

      container.resize(Parent::notifier()->maxId() + 1);

    }

    // \brief Constructor uses given value to initialize the map.

    //

    // It constructs a map uses a given value to initialize the map.

    // It adds all the items of the graph to the map.

    VectorMap(const Graph& graph, const Value& value) {

      Parent::attach(graph.notifier(Item()));

      container.resize(Parent::notifier()->maxId() + 1, value);

    }

  private:

    // \brief Copy constructor

    //

    // Copy constructor.

    VectorMap(const VectorMap& _copy) : Parent() {

      if (_copy.attached()) {

        Parent::attach(*_copy.notifier());

        container = _copy.container;

      }

    }

    // \brief Assign operator.

    //

    // This operator assigns for each item in the map the

    // value mapped to the same item in the copied map.

    // The parameter map should be indiced with the same

    // itemset because this assign operator does not change

    // the container of the map.

    VectorMap& operator=(const VectorMap& cmap) {

      return operator=<VectorMap>(cmap);

    }

    // \brief Template assign operator.

    //

    // The given parameter should conform to the ReadMap

    // concecpt and could be indiced by the current item set of

    // the NodeMap. In this case the value for each item

    // is assigned by the value of the given ReadMap.

    template <typename CMap>

    VectorMap& operator=(const CMap& cmap) {

      checkConcept<concepts::ReadMap<Key, _Value>, CMap>();

      const typename Parent::Notifier* nf = Parent::notifier();

      Item it;

      for (nf->first(it); it != INVALID; nf->next(it)) {

        set(it, cmap[it]);

      }

      return *this;

    }

  public:

    // \brief The subcript operator.

    //

    // The subscript operator. The map can be subscripted by the

    // actual items of the graph.

    Reference operator[](const Key& key) {

      return container[Parent::notifier()->id(key)];

    }

    // \brief The const subcript operator.

    //

    // The const subscript operator. The map can be subscripted by the

    // actual items of the graph.

    ConstReference operator[](const Key& key) const {

      return container[Parent::notifier()->id(key)];

    }

    // \brief The setter function of the map.

    //

    // It the same as operator[](key) = value expression.

    void set(const Key& key, const Value& value) {

      (*this)[key] = value;

    }

  protected:

    // \brief Adds a new key to the map.

    //

    // It adds a new key to the map. It is called by the observer notifier

    // and it overrides the add() member function of the observer base.

    virtual void add(const Key& key) {

      int id = Parent::notifier()->id(key);

      if (id >= int(container.size())) {

        container.resize(id + 1);

      }

    }

    // \brief Adds more new keys to the map.

    //

    // It adds more new keys to the map. It is called by the observer notifier

    // and it overrides the add() member function of the observer base.

    virtual void add(const std::vector<Key>& keys) {

      int max = container.size() - 1;

      for (int i = 0; i < int(keys.size()); ++i) {

        int id = Parent::notifier()->id(keys[i]);

        if (id >= max) {

          max = id;

        }

      }

      container.resize(max + 1);

    }

    // \brief Erase a key from the map.

    //

    // Erase a key from the map. It is called by the observer notifier

    // and it overrides the erase() member function of the observer base.

    virtual void erase(const Key& key) {

      container[Parent::notifier()->id(key)] = Value();

    }

    // \brief Erase more keys from the map.

    //

    // It erases more keys from the map. It is called by the observer notifier

    // and it overrides the erase() member function of the observer base.

    virtual void erase(const std::vector<Key>& keys) {

      for (int i = 0; i < int(keys.size()); ++i) {

        container[Parent::notifier()->id(keys[i])] = Value();

      }

    }

    // \brief Build the map.

    //

    // It builds the map. It is called by the observer notifier

    // and it overrides the build() member function of the observer base.

    virtual void build() {

      int size = Parent::notifier()->maxId() + 1;

      container.reserve(size);

      container.resize(size);

    }

    // \brief Clear the map.

    //

    // It erases all items from the map. It is called by the observer notifier

    // and it overrides the clear() member function of the observer base.

    virtual void clear() {

      container.clear();

    }

  private:

    Container container;

  };

}

#endif