/* === S Y N F I G ========================================================= */

/*!	\file synfig/rendering/resource.h

**	\brief Resource Header

**

**	$Id$

**

**	\legal

**	......... ... 2015 Ivan Mahonin

**

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

**	modify it under the terms of the GNU General Public License as

**	published by the Free Software Foundation; either version 2 of

**	the License, or (at your option) any later version.

**

**	This package 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.

**	\endlegal

*/

/* ========================================================================= */

/* === S T A R T =========================================================== */

#ifndef __SYNFIG_RENDERING_RESOURCE_H

#define __SYNFIG_RENDERING_RESOURCE_H

/* === H E A D E R S ======================================================= */

#include <vector></vector>

#include <etl handle=""></etl>

#include <mutex></mutex>

/* === M A C R O S ========================================================= */

/* === T Y P E D E F S ===================================================== */

/* === C L A S S E S & S T R U C T S ======================================= */

namespace synfig

{

namespace rendering

{

// TODO: move to ::synfig or to ::etl

class Resource: public etl::shared_object

{

public:

	typedef unsigned long long Id;

private:

	static Id last_id;

public:

	typedef etl::handle<resource> Handle;</resource>

	typedef std::vector<handle> List;</handle>

	class Storage: public etl::virtual_shared_object

	{

	public:

		typedef etl::handle<storage> Handle;</storage>

	private:

		mutable std::atomic<int> refcount;</int>

		friend class Resource;

		List resources;

		static const List blank;

	public:

		Storage();

		~Storage();

		virtual void ref() const;

		virtual bool unref_inactive() const;

		virtual bool unref() const;

		virtual int count() const;

	};

private:

	const Id id;

	mutable Storage::Handle alternatives;

	mutable std::mutex get_alternative_mtx;

public:

	Resource(): id(++last_id) { }

	Id get_id() const { return id; }

	const List& get_alternatives() const

		{ return alternatives ? alternatives->resources : Storage::blank; }

	void set_alternative(Handle other) const;

	void unset_alternative() const;

	template<typename t=""></typename>

	etl::handle<t> find_alternative() const</t>

	{

		const List &resources = get_alternatives();

		for(List::const_iterator i = resources.begin(); i != resources.end(); ++i)

			if (etl::handle<t> alternative = etl::handle<t>::cast_dynamic(*i))</t></t>

				return alternative;

		return etl::handle<t>();</t>

	}

	template<typename t=""></typename>

	etl::handle<t> get_alternative() const</t>

	{

		std::lock_guard<std::mutex> lock(get_alternative_mtx);</std::mutex>

		etl::handle<t> alternative = find_alternative<t>();</t></t>

		if (!alternative)

		{

			alternative = new T(*this);

			set_alterntive(alternative);

		}

		return alternative;

	}

};

} /* end namespace rendering */

} /* end namespace synfig */

/* -- E N D ----------------------------------------------------------------- */

#endif