/*!
	@file
	@author		Albert Semenov
	@date		10/2008
*/
/*
	This file is part of MyGUI.

	MyGUI is free software: you can redistribute it and/or modify
	it under the terms of the GNU Lesser General Public License as published by
	the Free Software Foundation, either version 3 of the License, or
	(at your option) any later version.

	MyGUI 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 Lesser General Public License for more details.

	You should have received a copy of the GNU Lesser General Public License
	along with MyGUI.  If not, see <http://www.gnu.org/licenses/>.
*/

// -- Based on boost::any, original copyright information follows --
// Copyright Kevlin Henney, 2000, 2001, 2002. All rights reserved.
//
// Distributed under the Boost Software License, Version 1.0.
// (See at http://www.boost.org/LICENSE_1_0.txt)
// -- End original copyright --

#ifndef __MYGUI_ANY_H__
#define __MYGUI_ANY_H__

#include "MyGUI_Prerequest.h"
#include "MyGUI_Diagnostic.h"
#include <algorithm>

#ifndef MYGUI_RTTI_DISABLE_TYPE_INFO
#include <typeinfo>
#endif

namespace MyGUI
{

	/** @example "Class Any usage"
	@code
	void f()
	{
		// RU: тестовый класс, с простыми типами все аналогично
		// EN: test class, with simple types all is similar
		struct Data { int value; };

		// RU: экземпляр и инициализация
		// EN: instance and initialization
		Data data;
		data.value = 0xDEAD;

		// RU: создастся копия класса Data
		// EN: copy of class Data will be created
		MyGUI::Any any = data;
		// RU: копия класса Data
		// EN: copy of class Data
		Data copy_data = *any.castType<Data>();
		// RU: теперь value == 0xDEAD
		// EN: now value == 0xDEAD
		int value = copy_data.value;


		// RU: создастся копия указателя на класс Data
		// EN: copy of pointer on class Data will be created
		any = &data;
		// RU: копия указателя на класс Data и конкретно на объект data
		// EN: copy of pointer on class Data and on object data
		Data* copy_ptr = *any.castType<Data*>();
		// RU: теперь data.value == 0
		// EN: now value == 0
		copy_ptr->value = 0;
	}
	@endcode
	*/

	class MYGUI_EXPORT Any
	{
	public:
		struct AnyEmpty { };
		static AnyEmpty Null;

		Any();
		Any(const Any::AnyEmpty& value);
		Any(const Any& other);

		template<typename ValueType>
		Any(const ValueType& value) :
			mContent(new Holder<ValueType>(value))
		{
		}

		~Any();

		Any& swap(Any& rhs);

		template<typename ValueType>
		Any& operator = (const ValueType& rhs)
		{
			Any(rhs).swap(*this);
			return *this;
		}

		Any& operator = (const Any::AnyEmpty& rhs);
		Any& operator = (const Any& rhs);

		bool empty() const;

#ifndef MYGUI_RTTI_DISABLE_TYPE_INFO
		const std::type_info& getType() const;

		template<typename ValueType>
		ValueType* castType(bool _throw = true) const
		{
			if (this->getType() == typeid(ValueType))
				return &static_cast<Any::Holder<ValueType> *>(this->mContent)->held;
			MYGUI_ASSERT(!_throw, "Bad cast from type '" << getType().name() << "' to '" << typeid(ValueType).name() << "'");
			return nullptr;
		}
#else
		template<typename ValueType>
		ValueType* castType(bool _throw = true) const
		{
			Any::Holder<ValueType>* data = dynamic_cast<Any::Holder<ValueType> *>(this->mContent);
			if (data != nullptr)
				return &data->held;
			MYGUI_ASSERT(!_throw, "Bad cast any");
			return nullptr;
		}
#endif

		void* castUnsafe() const;

	private:
		class Placeholder
		{
		public:
			virtual ~Placeholder() { }

		public:
#ifndef MYGUI_RTTI_DISABLE_TYPE_INFO
			virtual const std::type_info& getType() const = 0;
#endif
			virtual Placeholder* clone() const = 0;
		};

		template<typename ValueType>
		class Holder :
			public Placeholder
		{
		public:
			Holder(const ValueType& value) :
				held(value)
			{
			}

		public:
#ifndef MYGUI_RTTI_DISABLE_TYPE_INFO
			virtual const std::type_info& getType() const
			{
				return typeid(ValueType);
			}
#endif

			virtual Placeholder* clone() const
			{
				return new Holder(held);
			}

		public:
			ValueType held;

		private:
			Holder& operator=(const Holder&);
		};

	private:
		Placeholder* mContent;
	};

} // namespace MyGUI

#endif // __MYGUI_ANY_H__