/* -*- 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_ARRAY_MAP_H

#define LEMON_BITS_ARRAY_MAP_H

#include <memory>

#include <lemon/bits/traits.h>

#include <lemon/bits/alteration_notifier.h>

#include <lemon/concept_check.h>

#include <lemon/concepts/maps.h>

// \ingroup graphbits

// \file

// \brief Graph map based on the array storage.

namespace lemon {

  // \ingroup graphbits

  //

  // \brief Graph map based on the array storage.

  //

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

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

  // This map uses the allocators to implement the container functionality.

  //

  // The template parameters are the Graph, the current Item type and

  // the Value type of the map.

  template <typename _Graph, typename _Item, typename _Value>

  class ArrayMap

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

  public:

    // The graph type.

    typedef _Graph Graph;

    // The item type.

    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 const reference type of the map.

    typedef const _Value& ConstReference;

    // The reference type of the map.

    typedef _Value& Reference;

    // The notifier type.

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

    // The MapBase of the Map which imlements the core regisitry function.

    typedef typename Notifier::ObserverBase Parent;

  private:

    typedef std::allocator<Value> Allocator;

  public:

    // \brief Graph initialized map constructor.

    //

    // Graph initialized map constructor.

    explicit ArrayMap(const Graph& graph) {

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

      allocate_memory();

      Notifier* nf = Parent::notifier();

      Item it;

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

        int id = nf->id(it);;

        allocator.construct(&(values[id]), Value());

      }

    }

    // \brief Constructor to use default value to initialize the map.

    //

    // It constructs a map and initialize all of the the map.

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

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

      allocate_memory();

      Notifier* nf = Parent::notifier();

      Item it;

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

        int id = nf->id(it);;

        allocator.construct(&(values[id]), value);

      }

    }

  private:

    // \brief Constructor to copy a map of the same map type.

    //

    // Constructor to copy a map of the same map type.

    ArrayMap(const ArrayMap& copy) : Parent() {

      if (copy.attached()) {

        attach(*copy.notifier());

      }

      capacity = copy.capacity;

      if (capacity == 0) return;

      values = allocator.allocate(capacity);

      Notifier* nf = Parent::notifier();

      Item it;

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

        int id = nf->id(it);;

        allocator.construct(&(values[id]), copy.values[id]);

      }

    }

    // \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.

    ArrayMap& operator=(const ArrayMap& cmap) {

      return operator=<ArrayMap>(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>

    ArrayMap& 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 destructor of the map.

    //

    // The destructor of the map.

    virtual ~ArrayMap() {

      if (attached()) {

        clear();

        detach();

      }

    }

  protected:

    using Parent::attach;

    using Parent::detach;

    using Parent::attached;

  public:

    // \brief The subscript operator.

    //

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

    // actual keys of the graph.

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

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

      return values[id];

    }

    // \brief The const subscript operator.

    //

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

    // actual keys of the graph.

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

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

      return values[id];

    }

    // \brief Setter function of the map.

    //

    // Setter function of the map. Equivalent with map[key] = val.

    // This is a compatibility feature with the not dereferable maps.

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

      (*this)[key] = val;

    }

  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) {

      Notifier* nf = Parent::notifier();

      int id = nf->id(key);

      if (id >= capacity) {

        int new_capacity = (capacity == 0 ? 1 : capacity);

        while (new_capacity <= id) {

          new_capacity <<= 1;

        }

        Value* new_values = allocator.allocate(new_capacity);

        Item it;

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

          int jd = nf->id(it);;

          if (id != jd) {

            allocator.construct(&(new_values[jd]), values[jd]);

            allocator.destroy(&(values[jd]));

          }

        }

        if (capacity != 0) allocator.deallocate(values, capacity);

        values = new_values;

        capacity = new_capacity;

      }

      allocator.construct(&(values[id]), Value());

    }

    // \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) {

      Notifier* nf = Parent::notifier();

      int max_id = -1;

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

        int id = nf->id(keys[i]);

        if (id > max_id) {

          max_id = id;

        }

      }

      if (max_id >= capacity) {

        int new_capacity = (capacity == 0 ? 1 : capacity);

        while (new_capacity <= max_id) {

          new_capacity <<= 1;

        }

        Value* new_values = allocator.allocate(new_capacity);

        Item it;

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

          int id = nf->id(it);

          bool found = false;

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

            int jd = nf->id(keys[i]);

            if (id == jd) {

              found = true;

              break;

            }

          }

          if (found) continue;

          allocator.construct(&(new_values[id]), values[id]);

          allocator.destroy(&(values[id]));

        }

        if (capacity != 0) allocator.deallocate(values, capacity);

        values = new_values;

        capacity = new_capacity;

      }

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

        int id = nf->id(keys[i]);

        allocator.construct(&(values[id]), Value());

      }

    }

    // \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) {

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

      allocator.destroy(&(values[id]));

    }

    // \brief Erase more keys from the map.

    //

    // Erase 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) {

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

        allocator.destroy(&(values[id]));

      }

    }

    // \brief Builds 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() {

      Notifier* nf = Parent::notifier();

      allocate_memory();

      Item it;

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

        int id = nf->id(it);;

        allocator.construct(&(values[id]), Value());

      }

    }

    // \brief Clear the map.

    //

    // It erase 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() {

      Notifier* nf = Parent::notifier();

      if (capacity != 0) {

        Item it;

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

          int id = nf->id(it);

          allocator.destroy(&(values[id]));

        }

        allocator.deallocate(values, capacity);

        capacity = 0;

      }

    }

  private:

    void allocate_memory() {

      int max_id = Parent::notifier()->maxId();

      if (max_id == -1) {

        capacity = 0;

        values = 0;

        return;

      }

      capacity = 1;

      while (capacity <= max_id) {

        capacity <<= 1;

      }

      values = allocator.allocate(capacity);

    }

    int capacity;

    Value* values;

    Allocator allocator;

  };

}

#endif