// -*- c++ -*-

#ifndef ARRAY_MAP_H

#define ARRAY_MAP_H

#include <memory>

#include <hugo/map_iterator.h>

///\ingroup graphmaps

///\file

///\brief Graph maps that construates and destruates

///their elements dynamically.

namespace hugo {

  /// \addtogroup graphmaps

  /// @{

  /** 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 factory uses the allocators to implement 

   *  the container functionality.

   *

   *  The template parameter is the MapRegistry that the maps

   *  will belong to and the ValueType.

   */

  template <typename MapRegistry, typename Value> 

  class ArrayMap : public MapRegistry::MapBase {

  public:

    /// The graph type of the maps. 

    typedef typename MapRegistry::Graph Graph;

    /// The key type of the maps.

    typedef typename MapRegistry::KeyType KeyType;

    /// The iterator to iterate on the keys.

    typedef typename MapRegistry::KeyIt KeyIt;

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

    typedef typename MapRegistry::MapBase MapBase;

  public:

    /// The value type of the map.

    typedef Value ValueType;

    /// The reference type of the map;

    typedef Value& ReferenceType;

    /// The pointer type of the map;

    typedef Value* PointerType;

    /// The const value type of the map.

    typedef const Value ConstValueType;

    /// The const reference type of the map;

    typedef const Value& ConstReferenceType;

    /// The pointer type of the map;

    typedef const Value* ConstPointerType;

    typedef std::allocator<Value> Allocator;

    /** Default constructor for the map.

     */

    ArrayMap() : values(0), capacity(0) {}

    /** Graph and Registry initialized map constructor.

     */

    ArrayMap(const Graph& g, MapRegistry& r) : MapBase(g, r) {

      allocate_memory();

      for (KeyIt it(*MapBase::getGraph()); it != INVALID; ++it) {

	int id = MapBase::getGraph()->id(it);

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

      }								

    }

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

     */

    ArrayMap(const Graph& g, MapRegistry& r, const Value& v) 

      : MapBase(g, r) {

      allocate_memory();

      for (KeyIt it(*MapBase::getGraph()); it != INVALID; ++it) {

	int id = MapBase::getGraph()->id(it);

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

      }								

    }

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

     */

    ArrayMap(const ArrayMap& copy) : MapBase(*copy.graph, *copy.registry) {

      capacity = copy.capacity;

      if (capacity == 0) return;

      values = allocator.allocate(capacity);

      for (KeyIt it(*MapBase::getGraph()); it != INVALID; ++it) {

	int id = MapBase::getGraph()->id(it);

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

      }

    }

    /** Constructor to copy a map of an other map type.

     */

    template <typename CMap> ArrayMap(const CMap& copy) 

      : MapBase(copy), capacity(0), values(0) {

      if (MapBase::getGraph()) {

	allocate_memory();

	for (KeyIt it(*MapBase::getGraph()); it != INVALID; ++it) {

	  set(it, copy[it]);

	}

      }

    }

    /** Assign operator to copy a map of the same map type.

     */

    ArrayMap& operator=(const ArrayMap& copy) {

      if (&copy == this) return *this;

      if (capacity != 0) {

	MapBase::destroy();

	allocator.deallocate(values, capacity);

      }

      capacity = copy.capacity;

      if (capacity == 0) return *this;

      values = allocator.allocate(capacity);

      for (KeyIt it(*MapBase::getGraph()); it != INVALID; ++it) {

	int id = MapBase::getGraph()->id(it);

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

      }

      return *this;

    }

    /** Assign operator to copy a map an other map type.

     */

    template <typename CMap> ArrayMap& operator=(const CMap& copy) {

      if (MapBase::getGraph()) {

	MapBase::destroy();

      } 

      MapBase::operator=(copy);

      if (MapBase::getGraph()) {

	allocate_memory();

	for (KeyIt it(*MapBase::getGraph()); it != INVALID; ++it) {

	  set(it, copy[it]);

	}

      }

      return *this;

    }

    /** The destructor of the map.

     */

    virtual ~ArrayMap() {

      if (capacity != 0) {

	MapBase::destroy();

	allocator.deallocate(values, capacity);

      }

    }

    /**

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

     * actual keys of the graph. 

     */

    ReferenceType operator[](const KeyType& key) {

      int id = MapBase::getGraph()->id(key);

      return values[id];

    } 

    /**

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

     * actual keys of the graph. 

     */

    ConstReferenceType operator[](const KeyType& key) const {

      int id = MapBase::getGraph()->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 KeyType& key, const ValueType& val) {

      int id = MapBase::getGraph()->id(key);

      values[id] = val;

    }

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

     */

    void add(const KeyType& key) {

      int id = MapBase::getGraph()->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);;

	for (KeyIt it(*MapBase::getGraph()); it != INVALID; ++it) {

	  int jd = MapBase::getGraph()->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());

    }

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

     */

    void erase(const KeyType& key) {

      int id = MapBase::getGraph()->id(key);

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

    }

    /** Clear the data structure.

     */

    void clear() {	

      if (capacity != 0) {

	MapBase::destroy();

	allocator.deallocate(values, capacity);

	capacity = 0;

      }

    }

    /// The stl compatible pair iterator of the map.

    typedef MapIterator<ArrayMap> Iterator;

    /// The stl compatible const pair iterator of the map.

    typedef MapConstIterator<ArrayMap> ConstIterator;

    /** Returns the begin iterator of the map.

     */

    Iterator begin() {

      return Iterator(*this, KeyIt(*MapBase::getGraph()));

    }

    /** Returns the end iterator of the map.

     */

    Iterator end() {

      return Iterator(*this, INVALID);

    }

    /** Returns the begin ConstIterator of the map.

     */

    ConstIterator begin() const {

      return ConstIterator(*this, KeyIt(*MapBase::getGraph()));

    }

    /** Returns the end const_iterator of the map.

     */

    ConstIterator end() const {

      return ConstIterator(*this, INVALID);

    }

  private:

    void allocate_memory() {

      int max_id = -1;

      for (KeyIt it(*MapBase::getGraph()); it != INVALID; ++it) {

	int id = MapBase::getGraph()->id(it);

	if (id > max_id) {

	  max_id = id;

	}			

      }

      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