/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */

/*

 * Copyright (c) 2007 INRIA, Gustavo Carneiro

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation;

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 *

 * Authors: Gustavo Carneiro <gjcarneiro@gmail.com>,

 *          Mathieu Lacage <mathieu.lacage@sophia.inria.fr>

 */

#ifndef OBJECT_H

#define OBJECT_H

#include <stdint.h>

#include <string>

#include <vector>

#include "ptr.h"

#include "attribute.h"

#include "object-base.h"

#include "attribute-list.h"

namespace ns3 {

class Object;

class AttributeAccessor;

class AttributeValue;

class AttributeList;

class TraceSourceAccessor;

/**

 * \ingroup core

 * \defgroup object Object

 */

/**

 * \ingroup object

 * \brief a base class which provides memory management and object aggregation

 *

 * The memory management scheme is based on reference-counting with dispose-like

 * functionality to break the reference cycles. The reference count is increamented

 * and decremented with the methods Object::Ref and Object::Unref. If a reference cycle is

 * present, the user is responsible for breaking it by calling Object::Dispose in

 * a single location. This will eventually trigger the invocation of Object::DoDispose 

 * on itself and all its aggregates. The Object::DoDispose method is always automatically

 * invoked from the Object::Unref method before destroying the object, even if the user 

 * did not call Object::Dispose directly.

 */

class Object : public ObjectBase

{

public:

  static TypeId GetTypeId (void);

  /**

   * \brief Iterate over the objects aggregated to an ns3::Object.

   *

   * This iterator does not allow you to iterate over the initial

   * object used to call Object::GetAggregateIterator. 

   *

   * Note: this is a java-style iterator.

   */

  class AggregateIterator

  {

  public:

    AggregateIterator ();

    /**

     * \returns true if HasNext can be called and return a non-null

     *          pointer, false otherwise.

     */

    bool HasNext (void) const;

    /**

     * \returns the next aggregated object.

     */

    Ptr<const Object> Next (void);

  private:

    friend class Object;

    AggregateIterator (Ptr<const Object> first);

    Ptr<const Object> m_first;

    Ptr<const Object> m_current;

  };

  Object ();

  virtual ~Object ();

  /*

   * Implement the GetInstanceTypeId method defined in ObjectBase.

   */

  virtual TypeId GetInstanceTypeId (void) const;

  /**

   * Increment the reference count. This method should not be called

   * by user code. Object instances are expected to be used in conjunction

   * of the Ptr template which would make calling Ref unecessary and 

   * dangerous.

   */

  inline void Ref (void) const;

  /**

   * Decrement the reference count. This method should not be called

   * by user code. Object instances are expected to be used in conjunction

   * of the Ptr template which would make calling Ref unecessary and 

   * dangerous.

   */

  inline void Unref (void) const;

  /**

   * \returns a pointer to the requested interface or zero if it could not be found.

   */

  template <typename T>

  Ptr<T> GetObject (void) const;

  /**

   * \param tid the interface id of the requested interface

   * \returns a pointer to the requested interface or zero if it could not be found.

   */

  template <typename T>

  Ptr<T> GetObject (TypeId tid) const;

  /**

   * Run the DoDispose methods of this object and all the

   * objects aggregated to it.

   * After calling this method, the object is expected to be

   * totally unusable except for the Ref and Unref methods.

   * It is an error to call Dispose twice on the same object 

   * instance.

   *

   * This method is typically used to break reference cycles.

   */

  void Dispose (void);

  /**

   * \param other another object pointer

   *

   * This method aggregates the two objects together: after this

   * method returns, it becomes possible to call GetObject

   * on one to get the other, and vice-versa. 

   */

  void AggregateObject (Ptr<Object> other);

  /**

   * \returns an iterator to the first object aggregated to this

   *          object.

   *

   * If no objects are aggregated to this object, then, the returned

   * iterator will be empty and AggregateIterator::HasNext will

   * always return false.

   */

  AggregateIterator GetAggregateIterator (void) const;

protected:

  /**

   * This method is called by Object::Dispose or by the object's 

   * destructor, whichever comes first.

   *

   * Subclasses are expected to implement their real destruction

   * code in an overriden version of this method and chain

   * up to their parent's implementation once they are done.

   * i.e., for simplicity, the destructor of every subclass should

   * be empty and its content should be moved to the associated

   * DoDispose method.

   */

  virtual void DoDispose (void);

  /**

   * \param o the object to copy.

   *

   * Allow subclasses to implement a copy constructor.

   * While it is technically possible to implement a copy

   * constructor in a subclass, we strongly discourage you

   * to do so. If you really want to do it anyway, you have

   * to understand that this copy constructor will _not_

   * copy aggregated objects. i.e., if your object instance

   * is already aggregated to another object and if you invoke

   * this copy constructor, the new object instance will be

   * a pristine standlone object instance not aggregated to

   * any other object. It is thus _your_ responsability

   * as a caller of this method to do what needs to be done

   * (if it is needed) to ensure that the object stays in a

   * valid state.

   */

  Object (const Object &o);

private:

  template <typename T>

  friend Ptr<T> CreateObject (const AttributeList &attributes);

  template <typename T>

  friend Ptr<T> CopyObject (Ptr<T> object);

  template <typename T>

  friend Ptr<T> CopyObject (Ptr<const T> object);

  friend class ObjectFactory;

  friend class AggregateIterator;

  Ptr<Object> DoGetObject (TypeId tid) const;

  bool Check (void) const;

  bool CheckLoose (void) const;

  /**

   * Attempt to delete this object. This method iterates

   * over all aggregated objects to check if they all 

   * have a zero refcount. If yes, the object and all

   * its aggregates are deleted. If not, nothing is done.

   */

  void MaybeDelete (void) const;

  /**

   * \param tid an TypeId

   *

   * Invoked from ns3::CreateObject only.

   * Initialize the m_tid member variable to

   * keep track of the type of this object instance.

   */

  void SetTypeId (TypeId tid);

   /**

   * \param attributes the attribute values used to initialize 

   *        the member variables of this object's instance.

   *

   * Invoked from ns3::ObjectFactory::Create and ns3::CreateObject only.

   * Initialize all the member variables which were

   * registered with the associated TypeId.

   */

  void Construct (const AttributeList &attributes);

  /**

   * The reference count for this object. Each aggregate

   * has an individual reference count. When the global

   * reference count (the sum of all reference counts) 

   * reaches zero, the object and all its aggregates is 

   * deleted.

   */

  mutable uint32_t m_count;

  /**

   * Identifies the type of this object instance.

   */

  TypeId m_tid;

  /**

   * Set to true when the DoDispose method of the object

   * has run, false otherwise.

   */

  bool m_disposed;

  /**

   * A pointer to the next aggregate object. This is a circular

   * linked list of aggregated objects: the last one points

   * back to the first one. If an object is not aggregated to

   * any other object, the value of this field is equal to the

   * value of the 'this' pointer.

   */

  Object *m_next;

};

/**

 * \param object a pointer to the object to copy.

 * \returns a copy of the input object.

 *

 * This method invoke the copy constructor of the input object

 * and returns the new instance.

 */

template <typename T>

Ptr<T> CopyObject (Ptr<const T> object);

template <typename T>

Ptr<T> CopyObject (Ptr<T> object);

/**

 * \param attributes a list of attributes to set on the 

 *        object during construction.

 * \returns a pointer to a newly allocated object.

 *

 * This allocates an object on the heap and initializes

 * it with a set of attributes.

 */

template <typename T>

Ptr<T> CreateObject (const AttributeList &attributes);

/**

 * \param n1 name of attribute

 * \param v1 value of attribute

 * \param n2 name of attribute

 * \param v2 value of attribute

 * \param n3 name of attribute

 * \param v3 value of attribute

 * \param n4 name of attribute

 * \param v4 value of attribute

 * \param n5 name of attribute

 * \param v5 value of attribute

 * \param n6 name of attribute

 * \param v6 value of attribute

 * \param n7 name of attribute

 * \param v7 value of attribute

 * \param n8 name of attribute

 * \param v8 value of attribute

 * \param n9 name of attribute

 * \param v9 value of attribute

 * \returns a pointer to a newly allocated object.

 *

 * This allocates an object on the heap and initializes

 * it with a set of attributes.

 */

template <typename T>

Ptr<T> 

CreateObject (std::string n1 = "", const AttributeValue & v1 = EmptyAttributeValue (),

              std::string n2 = "", const AttributeValue & v2 = EmptyAttributeValue (),

              std::string n3 = "", const AttributeValue & v3 = EmptyAttributeValue (),

              std::string n4 = "", const AttributeValue & v4 = EmptyAttributeValue (),

              std::string n5 = "", const AttributeValue & v5 = EmptyAttributeValue (),

              std::string n6 = "", const AttributeValue & v6 = EmptyAttributeValue (),

              std::string n7 = "", const AttributeValue & v7 = EmptyAttributeValue (),

              std::string n8 = "", const AttributeValue & v8 = EmptyAttributeValue (),

              std::string n9 = "", const AttributeValue & v9 = EmptyAttributeValue ());

} // namespace ns3

namespace ns3 {

/*************************************************************************

 *   The Object implementation which depends on templates

 *************************************************************************/

void

Object::Ref (void) const

{

  m_count++;

}

void

Object::Unref (void) const

{

  NS_ASSERT (Check ());

  m_count--;

  if (m_count == 0)

    {

      MaybeDelete ();

    }

}

template <typename T>

Ptr<T> 

Object::GetObject () const

{

  Ptr<Object> found = DoGetObject (T::GetTypeId ());

  if (found != 0)

    {

      return Ptr<T> (dynamic_cast<T *> (PeekPointer (found)));

    }

  return 0;

}

template <typename T>

Ptr<T> 

Object::GetObject (TypeId tid) const

{

  Ptr<Object> found = DoGetObject (tid);

  if (found != 0)

    {

      return Ptr<T> (dynamic_cast<T *> (PeekPointer (found)));

    }

  return 0;

}

/*************************************************************************

 *   The helper functions which need templates.

 *************************************************************************/

template <typename T>

Ptr<T> CopyObject (Ptr<T> object)

{

  Ptr<T> p = Ptr<T> (new T (*PeekPointer (object)), false);

  NS_ASSERT (p->m_tid == object->m_tid);

  return p;

}

template <typename T>

Ptr<T> CopyObject (Ptr<const T> object)

{

  Ptr<T> p = Ptr<T> (new T (*PeekPointer (object)), false);

  NS_ASSERT (p->m_tid == object->m_tid);

  return p;

}

template <typename T>

Ptr<T> CreateObject (const AttributeList &attributes)

{

  Ptr<T> p = Ptr<T> (new T (), false);

  p->SetTypeId (T::GetTypeId ());

  p->Object::Construct (attributes);

  return p;  

}

template <typename T>

Ptr<T> 

CreateObject (std::string n1 = "", const AttributeValue & v1 = EmptyAttributeValue (),

              std::string n2 = "", const AttributeValue & v2 = EmptyAttributeValue (),

              std::string n3 = "", const AttributeValue & v3 = EmptyAttributeValue (),

              std::string n4 = "", const AttributeValue & v4 = EmptyAttributeValue (),

              std::string n5 = "", const AttributeValue & v5 = EmptyAttributeValue (),

              std::string n6 = "", const AttributeValue & v6 = EmptyAttributeValue (),

              std::string n7 = "", const AttributeValue & v7 = EmptyAttributeValue (),

              std::string n8 = "", const AttributeValue & v8 = EmptyAttributeValue (),

              std::string n9 = "", const AttributeValue & v9 = EmptyAttributeValue ())

{

  AttributeList attributes;

  if (n1 == "")

    {

      goto end;

    }

  attributes.SetWithTid (T::GetTypeId (), n1, v1);

  if (n2 == "")

    {

      goto end;

    }

  attributes.SetWithTid (T::GetTypeId (), n2, v2);

  if (n3 == "")

    {

      goto end;

    }

  attributes.SetWithTid (T::GetTypeId (), n3, v3);

  if (n4 == "")

    {

      goto end;

    }

  attributes.SetWithTid (T::GetTypeId (), n4, v4);

  if (n5 == "")

    {

      goto end;

    }

  attributes.SetWithTid (T::GetTypeId (), n5, v5);

  if (n6 == "")

    {

      goto end;

    }

  attributes.SetWithTid (T::GetTypeId (), n6, v6);

  if (n7 == "")

    {

      goto end;

    }

  attributes.SetWithTid (T::GetTypeId (), n7, v7);

  if (n8 == "")

    {

      goto end;

    }

  attributes.SetWithTid (T::GetTypeId (), n8, v8);

  if (n9 == "")

    {

      goto end;

    }

  attributes.SetWithTid (T::GetTypeId (), n9, v9);

 end:

  return CreateObject<T> (attributes);

}

} // namespace ns3

#endif /* OBJECT_H */