/*
 * Copyright (C) 2005, 2006, 2007 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1.  Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer. 
 * 2.  Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution. 
 * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
 *     its contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission. 
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef JSRetainPtr_h
#define JSRetainPtr_h

#include <JavaScriptCore/JSStringRef.h>
#include <algorithm>

namespace KJS {

    inline void JSRetain(JSStringRef string) { JSStringRetain(string); }
    inline void JSRelease(JSStringRef string) { JSStringRelease(string); }

    enum AdoptTag { Adopt };

    template <typename T> class JSRetainPtr {
    public:
        JSRetainPtr() : m_ptr(0) {}
        JSRetainPtr(T ptr) : m_ptr(ptr) { if (ptr) JSRetain(ptr); }

        JSRetainPtr(AdoptTag, T ptr) : m_ptr(ptr) { }
        
        JSRetainPtr(const JSRetainPtr& o) : m_ptr(o.m_ptr) { if (T ptr = m_ptr) JSRetain(ptr); }

        ~JSRetainPtr() { if (T ptr = m_ptr) JSRelease(ptr); }
        
        template <typename U> JSRetainPtr(const JSRetainPtr<U>& o) : m_ptr(o.get()) { if (T ptr = m_ptr) JSRetain(ptr); }
        
        T get() const { return m_ptr; }
        
        T releaseRef() { T tmp = m_ptr; m_ptr = 0; return tmp; }
        
        T operator->() const { return m_ptr; }
        
        bool operator!() const { return !m_ptr; }
    
        // This conversion operator allows implicit conversion to bool but not to other integer types.
        typedef T (JSRetainPtr::*UnspecifiedBoolType)() const;
        operator UnspecifiedBoolType() const { return m_ptr ? &JSRetainPtr::get : 0; }
        
        JSRetainPtr& operator=(const JSRetainPtr&);
        template <typename U> JSRetainPtr& operator=(const JSRetainPtr<U>&);
        JSRetainPtr& operator=(T);
        template <typename U> JSRetainPtr& operator=(U*);

        void adopt(T);
        
        void swap(JSRetainPtr&);

    private:
        T m_ptr;
    };
    
    template <typename T> inline JSRetainPtr<T>& JSRetainPtr<T>::operator=(const JSRetainPtr<T>& o)
    {
        T optr = o.get();
        if (optr)
            JSRetain(optr);
        T ptr = m_ptr;
        m_ptr = optr;
        if (ptr)
            JSRelease(ptr);
        return *this;
    }
    
    template <typename T> template <typename U> inline JSRetainPtr<T>& JSRetainPtr<T>::operator=(const JSRetainPtr<U>& o)
    {
        T optr = o.get();
        if (optr)
            JSRetain(optr);
        T ptr = m_ptr;
        m_ptr = optr;
        if (ptr)
            JSRelease(ptr);
        return *this;
    }
    
    template <typename T> inline JSRetainPtr<T>& JSRetainPtr<T>::operator=(T optr)
    {
        if (optr)
            JSRetain(optr);
        T ptr = m_ptr;
        m_ptr = optr;
        if (ptr)
            JSRelease(ptr);
        return *this;
    }

    template <typename T> inline void JSRetainPtr<T>::adopt(T optr)
    {
        T ptr = m_ptr;
        m_ptr = optr;
        if (ptr)
            JSRelease(ptr);
    }
    
    template <typename T> template <typename U> inline JSRetainPtr<T>& JSRetainPtr<T>::operator=(U* optr)
    {
        if (optr)
            JSRetain(optr);
        T ptr = m_ptr;
        m_ptr = optr;
        if (ptr)
            JSRelease(ptr);
        return *this;
    }

    template <class T> inline void JSRetainPtr<T>::swap(JSRetainPtr<T>& o)
    {
        std::swap(m_ptr, o.m_ptr);
    }

    template <class T> inline void swap(JSRetainPtr<T>& a, JSRetainPtr<T>& b)
    {
        a.swap(b);
    }

    template <typename T, typename U> inline bool operator==(const JSRetainPtr<T>& a, const JSRetainPtr<U>& b)
    { 
        return a.get() == b.get(); 
    }

    template <typename T, typename U> inline bool operator==(const JSRetainPtr<T>& a, U* b)
    { 
        return a.get() == b; 
    }
    
    template <typename T, typename U> inline bool operator==(T* a, const JSRetainPtr<U>& b) 
    {
        return a == b.get(); 
    }
    
    template <typename T, typename U> inline bool operator!=(const JSRetainPtr<T>& a, const JSRetainPtr<U>& b)
    { 
        return a.get() != b.get(); 
    }

    template <typename T, typename U> inline bool operator!=(const JSRetainPtr<T>& a, U* b)
    {
        return a.get() != b; 
    }

    template <typename T, typename U> inline bool operator!=(T* a, const JSRetainPtr<U>& b)
    { 
        return a != b.get(); 
    }

} // namespace KJS

using KJS::JSRetainPtr;

#endif // KJS_JSRetainPtr_h