// Copyright (c) 2016-2018 Kiwano - Nomango
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

#pragma once
#include <kiwano/2d/Actor.h>
#include <kiwano/core/Resource.h>
#include <kiwano/renderer/RenderTarget.h>
#include <kiwano/renderer/GifImage.h>

namespace kiwano
{
	// GIF 精灵
	class KGE_API GifSprite
		: public Actor
	{
	public:
		using LoopDoneCallback	= Function<void(int)>;
		using DoneCallback		= Function<void()>;

		GifSprite();

		GifSprite(
			String const& file_path
		);

		GifSprite(
			Resource const& res
		);

		GifSprite(
			GifImage gif
		);

		bool Load(
			String const& file_path
		);

		bool Load(
			Resource const& res
		);

		bool Load(
			GifImage gif
		);

		// 设置 GIF 动画循环次数
		inline void SetLoopCount(int loops)						{ total_loop_count_ = loops; }

		// 设置 GIF 动画每次循环结束回调函数
		inline void SetLoopDoneCallback(LoopDoneCallback const& cb)	{ loop_cb_ = cb; }

		// 设置 GIF 动画结束回调函数
		inline void SetDoneCallback(DoneCallback const& cb)			{ done_cb_ = cb; }

		// 设置 GIF 图像
		void SetGifImage(GifImage const& gif);

		// 重新播放动画
		void RestartAnimation();

		inline LoopDoneCallback	GetLoopDoneCallback() const			{ return loop_cb_; }

		inline DoneCallback		GetDoneCallback() const				{ return done_cb_; }

		inline GifImage const&	GetGifImage() const					{ return gif_; }

		void OnRender(RenderTarget* rt) override;

	protected:
		void Update(Duration dt) override;

		inline bool IsLastFrame() const								{ return (next_index_ == 0); }

		inline bool EndOfAnimation() const							{ return IsLastFrame() && loop_count_ == total_loop_count_ + 1; }

		void ComposeNextFrame();

		void DisposeCurrentFrame();

		void OverlayNextFrame();

		void SaveComposedFrame();

		void RestoreSavedFrame();

		void ClearCurrentFrameArea();

	protected:
		bool				animating_;
		int					total_loop_count_;
		int					loop_count_;
		size_t				next_index_;
		Duration			frame_elapsed_;
		LoopDoneCallback	loop_cb_;
		DoneCallback		done_cb_;
		GifImage			gif_;
		GifImage::Frame		frame_;
		Texture				saved_frame_;
		TextureRenderTarget	frame_rt_;
	};
}