/* -*- 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_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 what

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

   /// the map. 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 of the maps. 

     typedef _Graph Graph;

     /// The item type of the map.

     typedef _Item Item;

     /// The reference map tag.

     typedef True ReferenceMapTag;

     /// The key type of the maps.

     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);

       }								

     }

     /// \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 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>

     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;

     }

     /// \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 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 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 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 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 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() {

       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 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