// 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
{
	KGE_DECLARE_SMART_PTR(GifSprite);

	/**
	* \addtogroup Actors
	* @{
	*/

	/**
	* \~chinese
	* @brief GIF 精灵
	*/
	class KGE_API GifSprite
		: public Actor
	{
	public:
		/// \~chinese
		/// @brief GIF播放循环结束回调
		using LoopDoneCallback	= Function<void(int /* times */)>;

		/// \~chinese
		/// @brief GIF播放结束回调
		using DoneCallback		= Function<void()>;

		GifSprite();

		/// \~chinese
		/// @brief 构造GIF精灵
		/// @param file_path GIF图片路径
		GifSprite(String const& file_path);

		/// \~chinese
		/// @brief 构造GIF精灵
		/// @param res GIF图片资源
		GifSprite(Resource const& res);

		/// \~chinese
		/// @brief 构造GIF精灵
		/// @param gif GIF图片
		GifSprite(GifImagePtr gif);

		/// \~chinese
		/// @brief 加载GIF图片
		/// @param file_path GIF图片路径
		bool Load(String const& file_path);

		/// \~chinese
		/// @brief 加载GIF图片
		/// @param res GIF图片资源
		bool Load(Resource const& res);

		/// \~chinese
		/// @brief 加载GIF图片
		/// @param gif GIF图片
		bool Load(GifImagePtr gif);

		/// \~chinese
		/// @brief 设置 GIF 动画循环次数
		void SetLoopCount(int loops);

		/// \~chinese
		/// @brief 设置 GIF 动画每次循环结束回调函数
		void SetLoopDoneCallback(LoopDoneCallback const& cb);

		/// \~chinese
		/// @brief 设置 GIF 动画结束回调函数
		void SetDoneCallback(DoneCallback const& cb);

		/// \~chinese
		/// @brief 设置 GIF 图像
		void SetGifImage(GifImagePtr gif);

		/// \~chinese
		/// @brief 重新播放 GIF 动画
		void RestartAnimation();

		/// \~chinese
		/// @brief 获取 GIF 动画循环结束回调
		LoopDoneCallback GetLoopDoneCallback() const;

		/// \~chinese
		/// @brief 获取 GIF 动画播放结束回调
		DoneCallback GetDoneCallback() const;

		/// \~chinese
		/// @brief 获取 GIF 图片
		GifImagePtr GetGifImage() const;

		void OnRender(RenderTarget* rt) override;

	private:
		void Update(Duration dt) override;

		/// \~chinese
		/// @brief 是否是最后一帧
		bool IsLastFrame() const;

		/// \~chinese
		/// @brief 动画是否已结束
		bool EndOfAnimation() const;

		/// \~chinese
		/// @brief 合成下一帧
		void ComposeNextFrame();

		/// \~chinese
		/// @brief 解析当前图像帧
		void DisposeCurrentFrame();

		/// \~chinese
		/// @brief 覆盖下一帧
		void OverlayNextFrame();

		/// \~chinese
		/// @brief 保存合成后的图像帧
		void SaveComposedFrame();

		/// \~chinese
		/// @brief 恢复已保存的图像帧
		void RestoreSavedFrame();

		/// \~chinese
		/// @brief 清空当前图像区域
		void ClearCurrentFrameArea();

	private:
		bool					animating_;
		int						total_loop_count_;
		int						loop_count_;
		size_t					next_index_;
		Duration				frame_elapsed_;
		LoopDoneCallback		loop_cb_;
		DoneCallback			done_cb_;
		GifImagePtr				gif_;
		GifImage::Frame			frame_;
		TexturePtr				saved_frame_;
		TexturePtr				frame_to_render_;
		TextureRenderTargetPtr	frame_rt_;
	};

	/** @} */

	inline void							GifSprite::SetLoopCount(int loops)							{ total_loop_count_ = loops; }

	inline void							GifSprite::SetLoopDoneCallback(LoopDoneCallback const& cb)	{ loop_cb_ = cb; }

	inline void							GifSprite::SetDoneCallback(DoneCallback const& cb)			{ done_cb_ = cb; }

	inline GifSprite::LoopDoneCallback	GifSprite::GetLoopDoneCallback() const						{ return loop_cb_; }

	inline GifSprite::DoneCallback		GifSprite::GetDoneCallback() const							{ return done_cb_; }

	inline GifImagePtr					GifSprite::GetGifImage() const								{ return gif_; }

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

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