/* -*- C++ -*-
 *
 * This file is a part of LEMON, a generic C++ optimization library
 *
 * Copyright (C) 2003-2006
 * 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/concept/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.getNotifier(Item()));
      allocate_memory();
      Notifier* notifier = Parent::getNotifier();
      Item it;
      for (notifier->first(it); it != INVALID; notifier->next(it)) {
	int id = notifier->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.getNotifier(Item()));
      allocate_memory();
      Notifier* notifier = Parent::getNotifier();
      Item it;
      for (notifier->first(it); it != INVALID; notifier->next(it)) {
	int id = notifier->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.getNotifier());
      }
      capacity = copy.capacity;
      if (capacity == 0) return;
      values = allocator.allocate(capacity);
      Notifier* notifier = Parent::getNotifier();
      Item it;
      for (notifier->first(it); it != INVALID; notifier->next(it)) {
	int id = notifier->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<concept::ReadMap<Key, _Value>, CMap>();
      const typename Parent::Notifier* notifier = Parent::getNotifier();
      Item it;
      for (notifier->first(it); it != INVALID; notifier->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::getNotifier()->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::getNotifier()->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* notifier = Parent::getNotifier();
      int id = notifier->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 (notifier->first(it); it != INVALID; notifier->next(it)) {
	  int jd = notifier->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* notifier = Parent::getNotifier();
      int max_id = -1;
      for (int i = 0; i < (int)keys.size(); ++i) {
	int id = notifier->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 (notifier->first(it); it != INVALID; notifier->next(it)) {
	  int id = notifier->id(it);
	  bool found = false;
	  for (int i = 0; i < (int)keys.size(); ++i) {
	    int jd = notifier->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 = notifier->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::getNotifier()->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::getNotifier()->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* notifier = Parent::getNotifier();
      allocate_memory();
      Item it;
      for (notifier->first(it); it != INVALID; notifier->next(it)) {
	int id = notifier->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* notifier = Parent::getNotifier();
      if (capacity != 0) {
	Item it;
	for (notifier->first(it); it != INVALID; notifier->next(it)) {
	  int id = notifier->id(it);
	  allocator.destroy(&(values[id]));
	}								
	allocator.deallocate(values, capacity);
	capacity = 0;
      }
    }

  private:
      
    void allocate_memory() {
      int max_id = Parent::getNotifier()->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