//////////////////////////////////////////////////////////////////////////////
//主要功能: Undo and Redo的全局操作函数，为了区分符号修改与文件修改的Redo/Undo
//
//程序编写:		2006-12-07
/////////////////////////////////////////////////////////////////////////////

// Action.h: interface for the CAction class.
//
// Actions are undoable operations. This class abstracts that notion
// by defining the following interface:
//
//		void Do();
//			-- carry out the operation; generally called only once;
//			-- usually, the action must save the existing state before
//			-- performing its operation
//		void Undo();
//			-- called to undo what was done in Do(); usually must
//			-- save the new state, as created by Do(), before reverting
//			-- to the previous state before Do()
//		void Redo();
//			-- called to redo an undone action; generally this is
//			-- different from Do() because all states have already
//			-- been saved explicitly by Do() or Undo(); occasionally,
//			-- a state may be more difficult to store than to compute,
//			-- so then this routine may just call Do()
//
// Each derived class should call its base class's implementation of
// these routines.
//
// Most routines are virtual to allow overrides -- even GetActionName()
// is redefined in one derived action (CREStyleAction). Performance
// is not really a factor as doing the operation the action encapsulates
// will be far more expensive in the general case.
//
//////////////////////////////////////////////////////////////////////
#pragma once
#include <chrono>
#pragma warning(disable:4786)
#include "UMString.h"

class CActionVisitor;
class BlobSerializer;

namespace NAction
{
	enum ActionType
	{
		ActionTypeLayerRename = 1,					// 图层重命名
		ActionTypeLayerAdd = 2,						// 图层添加
		ActionTypeLayerDelete = 3,					// 图层删除
		ActionTypeLayerDragDrop = 4,				// 图层拖拽
		ActionTypeLayerEmbellishCurveAdd = 5,		// 图层添加曲线修饰
		ActionTypeLayerEmbellishCurveDelete = 6,	// 图层删除曲线修饰
		ActionTypeLayerEmbellishCurveMoveUp = 7,	// 图层删除曲线修饰
		ActionTypeLayerEmbellishCurveMoveDown = 8,	// 图层删除曲线修饰
		ActionTypeLayerEmbellishPointAdd = 9,		// 图层添加点修饰
		ActionTypeLayerEmbellishPointDelete = 10,	// 图层删除点修饰
	};

	class CAction
	{
	public:
		CAction(void *pActionTarget, UINT uActionType = 0, bool bAutoNotify = true);
		virtual ~CAction();

		/**
		 * 设置 actionTarget，建议不要随便调用，只有反序列化等少数场景才调用它
		 * 
		 * \param pActionTarget
		 */
		void SetActionTarget(void* pActionTarget);

		const std::string& GetUUID() const;

		void SetUUID(const std::string& uuid);

		/**
		 * 获取该 Action 发生的时间，如果没有单独设置，则是该对象创建的时间
		 * 
		 * \return 
		 */
		std::chrono::system_clock::time_point GetTimePoint() const;

		/**
		 * 设置 Action 发生的时间
		 * 
		 * \param timepoint
		 */
		void SetTimePoint(std::chrono::system_clock::time_point timepoint);

		/**
		 * 接收访问者
		 * 
		 * \param visitor
		 */
		virtual void accept(CActionVisitor& visitor) = 0;

		// Notifies the Undo Manager of this action; this
		// routine will be called automatically if autoNotify
		// is true; otherwise, it must be called explicitly.
		void			NotifyUndoManager();

		void			SetActionType(const UINT type);
		UINT			GetActionType();

		/**
		 * 获取 Action 名称，区别于下面的 GetName，它依赖 type，而这个 type 又是可以随意更改的
		 * 
		 * \return 
		 */
		virtual std::string GetActionName() const = 0;

		// Get or set a the name of the action.
		const UMString&	GetName() const;

		// do the operation
		virtual void	Do();
		// undo the operation
		virtual void	Undo();
		// redo the operation
		virtual void	Redo();
		// finish the action; useful saving important
		// but last-minute bits of data and ending long
		// duration actions
		virtual void	Finish();
		// is the action done or undone?
		virtual bool	IsUndone() const;

		// is the action finished yet?
		bool			IsFinished() const;
		// was the action successful in performing the
		// operation? generally used for OLE operations
		bool			IsSuccess() const;

		// should the action notify the undo manager
		// automatically? (you must call notify the
		// undo manager yourself if not.)
		void			SetAutoNotify(bool an);

		friend class BlobSerializer;

	protected:
		// a pointer to what the action affects; this is
		// usually a container of some sort -- subclasses
		// add something more specific (e.g., a contained
		// subview); it's generic, cast as necessary
		void *			actionTarget;
		// indicates whether the undo manager should
		// be notified automatically of when an action
		// has been done.
		bool			autoNotify;
		// indicates whether the action is complete;
		// some actions, like typing, have a duration
		// longer than a single call to Do()
		bool			finished;
		// indicates whether the action has been undone or not;
		// after do & redo, it's false; after undo; it's true;
		bool			undone;
		// for operations which have a reasonable probability
		// of failure; generally used in highly dynamic situations
		bool			success;
		// used for both identifying the particular action to
		// perform (e.g., an edit action can be a cut or paste)
		// as well as a resource string describing the action.
		UINT			actionType;
		// name of the action; usually dependent on the action
		// type and obtained from a resource; could be font name
		// or something else though.
		UMString		name;
		bool			done;

	private:
		std::string m_uuid;
		std::chrono::system_clock::time_point m_timepoint;
	};
}