/* -*-c++-*- Producer - Copyright (C) 2001-2004  Don Burns
 *
 * This library is open source and may be redistributed and/or modified under
 * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or
 * (at your option) any later version.  The full license is in LICENSE file
 * included with this distribution, and on the openscenegraph.org website.
 *
 * This library 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
 * OpenSceneGraph Public License for more details.
 */


#ifndef PRODUCER_REFERENCED
#define PRODUCER_REFERENCED 1

#include <Producer/Export>

// When building Producer with Java bindings we derive from NoodleGlue::CBridgable
// and disable the local ref/unref as this is done in Noodleglue
//#define PRODUCER_JAVA_BUILD

#ifdef PRODUCER_JAVA_BUILD
#include <NoodleGlue/Bridgable.h>
#endif

#include <iostream>
#include <typeinfo>


namespace Producer {

#ifndef PRODUCER_JAVA_BUILD

/** Base class from providing referencing counted objects.*/
class PR_EXPORT Referenced
{
    public:
        Referenced() { _refCount=0; }
        Referenced(const Referenced&) { _refCount=0; }

        inline Referenced& operator = (Referenced&) { return *this; }

        /** increment the reference count by one, indicating that 
            this object has another pointer which is referencing it.*/
        inline void ref() const { ++_refCount; }
        
        /** decrement the reference count by one, indicating that 
            a pointer to this object is referencing it.  If the
            reference count goes to zero, it is assumed that this object
            is no longer referenced and is automatically deleted.*/
        inline void unref() const { --_refCount; 
                                     if (_refCount==0) 
                                     {
                                         delete this; 
                                     }
                                     else if( _refCount<0) throw 1;  }
        
        /** decrement the reference count by one, indicating that 
            a pointer to this object is referencing it.  However, do
            not delete it, even if ref count goes to 0.  Warning, unref_nodelete() 
            should only be called if the user knows exactly who will
            be resonsible for, one should prefer unref() over unref_nodelete() 
            as the later can lead to memory leaks.*/
        inline void unref_nodelete() const { --_refCount; }
        
        /** return the number pointers currently referencing this object. */
        inline int getReferenceCount() const { return _refCount; }

    protected:
        virtual ~Referenced()
    {
            if (_refCount>0)
            {
              std::cerr <<"Warning: deleting still referenced object "<<this<<" of type '"<<typeid(this).name()<<"'"<<std::endl;
              std::cerr <<"         the final reference count was "<<_refCount<<", memory corruption possible."<<std::endl;
            }
    }
        mutable int _refCount;
};
#else
/** Java wrappers use the CBridgable base-class for referencing
* and garbage collection.
*/
class PR_EXPORT Referenced : public NoodleGlue::CBridgable 
{
	public:
		/// Method not used in NoodleGlue referencing 
		inline void unref_nodelete() const { --_refCount; }

	protected:
		virtual ~Referenced() {}
};
#endif

/** Smart pointer for handling referenced counted objects.*/
template<class T>
class ref_ptr
{

    public:
        typedef T element_type;

        ref_ptr() :_ptr(0L) {}
        ref_ptr(T* t):_ptr(t)              { if (_ptr) _ptr->ref(); }
        ref_ptr(const ref_ptr& rp):_ptr(rp._ptr)  { if (_ptr) _ptr->ref(); }
        ~ref_ptr()                         { if (_ptr)
                                             { 
                                                 _ptr->unref(); 
                                                 _ptr = 0L;
                                             }
                                           }

        inline ref_ptr& operator = (const ref_ptr& rp)
        {
            if (_ptr==rp._ptr) return *this;
            T* tmp_ptr = _ptr;
            _ptr = rp._ptr;
            if (_ptr) _ptr->ref();
            // unref second to prevent any deletion of any object which might
            // be referenced by the other object. i.e rp is child of the
            // original _ptr.
            if (tmp_ptr) tmp_ptr->unref();
            return *this;
        }

        inline ref_ptr& operator = (T* ptr)
        {
            if (_ptr==ptr) return *this;
            T* tmp_ptr = _ptr;
            _ptr = ptr;
            if (_ptr) _ptr->ref();
            // unref second to prevent any deletion of any object which might
            // be referenced by the other object. i.e rp is child of the
            // original _ptr.
            if (tmp_ptr) tmp_ptr->unref();
            return *this;
        }

        inline bool operator == (const ref_ptr& rp) const
        {
            return (_ptr==rp._ptr);
        }

        inline bool operator == (const T* ptr) const
        {
            return (_ptr==ptr);
        }

        inline bool operator != (const ref_ptr& rp) const
        {
            return (_ptr!=rp._ptr);
        }

        inline bool operator != (const T* ptr) const
        {
            return (_ptr!=ptr);
        }

        inline bool operator < (const ref_ptr& rp) const
        {
            return (_ptr<rp._ptr);
        }

        inline bool operator > (const ref_ptr& rp) const
        {
            return (_ptr>rp._ptr);
        }

        inline bool operator > (const T* ptr) const
        {
            return (_ptr>ptr);
        }

        inline T& operator*()  { return *_ptr; }

        inline const T& operator*() const { return *_ptr; }

        inline T* operator->() { return _ptr; }

        inline const T* operator->() const   { return _ptr; }

    inline bool operator!() const    { return _ptr==0L; }

    inline bool valid() const    { return _ptr!=0L; }
        
        inline T* get() { return _ptr; }

        inline const T* get() const { return _ptr; }

        /** take control over the object pointed to by ref_ptr, unreference but do not delete even if ref count goes to 0,
          * return the pointer to the object.
          * Note, do not use this unless you are 100% sure your code handles the deletion of the object correctly, and
          * only use when absolutely required.*/
        inline T* take() { T* tmp=_ptr; if (_ptr) _ptr->unref_nodelete(); _ptr=0; return tmp;}

    private:
        T* _ptr;
};


template <class T> class Reffed : public T, public Referenced {};

}

#endif
