/* -*- C++ -*-

  * lemon/bits/array_map.h - Part of LEMON, a generic C++ optimization library

  *

  * Copyright (C) 2005 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_ARRAY_MAP_H

 #define LEMON_ARRAY_MAP_H

 #include <memory>

 #include <lemon/bits/map_iterator.h>

 #include <lemon/concept_check.h>

 #include <lemon/concept/maps.h>

 /// \ingroup graphmapfactory

 /// \file

 /// \brief Graph maps that construct and destruct

 /// their elements dynamically.

 namespace lemon {

   /// \ingroup graphmapfactory

   ///

   /// \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 parameter is the AlterationNotifier that the maps

   /// will belong to and the Value.

   template <typename _Graph, 

 	    typename _Item,

 	    typename _Value>

   class ArrayMap : public AlterationNotifier<_Item>::ObserverBase {

     typedef _Item Item;

   public:

     /// The graph type of the maps. 

     typedef _Graph Graph;

     /// The key type of the maps.

     typedef _Item Key;

     typedef AlterationNotifier<_Item> Registry;

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

     typedef typename Registry::ObserverBase Parent;

     /// The value type of the map.

     typedef _Value Value;

   private:

     typedef std::allocator<Value> Allocator;

   public:

     /// Graph and Registry initialized map constructor.

     ArrayMap(const Graph& _g) : graph(&_g) {

       Item it;

       attach(_g.getNotifier(Item()));

       allocate_memory();

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

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

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

       }								

     }

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

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

     ArrayMap(const Graph& _g, const Value& _v) : graph(&_g) {

       Item it;

       attach(_g.getNotifier(_Item()));

       allocate_memory();

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

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

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

       }								

     }

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

     ArrayMap(const ArrayMap& copy) : Parent(), graph(copy.graph) {

       if (copy.attached()) {

 	attach(*copy.getRegistry());

       }

       capacity = copy.capacity;

       if (capacity == 0) return;

       values = allocator.allocate(capacity);

       Item it;

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

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

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

       }

     }

     /// \brief The destructor of the map.

     ///     

     /// The destructor of the map.

     virtual ~ArrayMap() {      

       if (attached()) {

 	clear();

 	detach();

       }

     }

   private:

     ArrayMap& operator=(const ArrayMap&);

   protected:

     using Parent::attach;

     using Parent::detach;

     using Parent::attached;

     const Graph* getGraph() {

       return graph;

     }

   public:

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

     ///actual keys of the graph. 

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

       int id = graph->id(key);

       return values[id];

     } 

     ///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 = graph->id(key);

       return values[id];

     }

     /// 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:

     /// Add a new key to the map. It called by the map registry.

     void add(const Key& key) {

       int id = graph->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 (graph->first(it); it != INVALID; graph->next(it)) {

 	  int jd = graph->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());

     }

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

       int max_id = -1;

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

 	int id = graph->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 (graph->first(it); it != INVALID; graph->next(it)) {

 	  int id = graph->id(it);

 	  bool found = false;

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

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

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

       }

     }

     /// Erase a key from the map. It called by the map registry.

     void erase(const Key& key) {

       int id = graph->id(key);

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

     }

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

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

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

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

       }

     }

     void build() {

       allocate_memory();

       Item it;

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

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

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

       }								

     }

     void clear() {	

       if (capacity != 0) {

 	Item it;

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

 	  int id = graph->id(it);

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

 	}								

 	allocator.deallocate(values, capacity);

 	capacity = 0;

       }

     }

   private:

     void allocate_memory() {

       int max_id = graph->maxId(_Item());

       if (max_id == -1) {

 	capacity = 0;

 	values = 0;

 	return;

       }

       capacity = 1;

       while (capacity <= max_id) {

 	capacity <<= 1;

       }

       values = allocator.allocate(capacity);	

     }      

     const Graph* graph;

     int capacity;

     Value* values;

     Allocator allocator;

   };		

 }

 #endif //LEMON_ARRAY_MAP_H