/* -*- C++ -*-

 *

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

 *

 * Copyright (C) 2003-2008

 * 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/bits/traits.h>

#include <lemon/bits/utility.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 what

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

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

  ///

  /// \param Notifier The AlterationNotifier that will notify this map.

  /// \param Item The item type of the graph items.

  /// \param Value The value type of the map.

  /// 

  /// \author Balazs Dezso  	

  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);

    }

    /// \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 be 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 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 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 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.

    ///

    /// Erase more keys from the map. It 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 Buildes the map.

    ///	

    /// It buildes the map. It 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 erase all items from the map. It 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