#pragma once


struct CommandFlags
{
	enum Enumeration
	{
		None = 0x00,
		SubChainStart = 0x01,	// Command will start a new command chain (UseShader for example)
		SubChainEnd = 0x02,		// Command will end a command chain (Render)
		Unique = 0x04,			// Similar commands should not be reduced to one Command
		StartChain = 0x08,		// Command will generate a new command chain		
		EndChain = 0x10,		// Command will end the command chain (RenderGeometry for example)
		FlushChain = 0x20,		// Command will end the command chain (RenderGeometry for example)
	};
};

struct ICommandUser;
struct Command
{

	Command(ICommandUser* inOwner, unsigned char inFlags, unsigned char inType, unsigned char inPriority, unsigned char inSubPriority = 0)
		: Owner(inOwner)
		, Flags(inFlags)
		, Priority(inPriority)
		, SubPriority(inSubPriority)
		, Type(inType)
	{
	}

	ICommandUser* Owner;
	union
	{
		struct  
		{
			UINT8 Priority;
			UINT8 SubPriority;
			UINT8 Flags;
			UINT8 Type;
		};
		UINT32 CommandInfo;
	};
};

struct CommandExecuteResult
{
	enum Enumeration
	{
		None,		// Execution done, proceed to the next Command
		RetrySubChain,	// Execution should start from a previous "SubChainStart"-flagged Command
		RetrySubChainSkipHead // Equal to the above result but skips the as "SubChainStart"-flagged Command
	};
};


struct IRenderCommandNode;
struct ICommandBuffer;
struct __declspec(novtable) ICommandUser
{
	virtual ~ICommandUser() {}

	virtual const std::vector<Command*>& GetCommands() const = 0;
	virtual CommandExecuteResult::Enumeration ExecuteCommand(unsigned char argCommandType, ICommandBuffer& argCurrentBuffer, uint32 argCurrentPositon) = 0;

	virtual void AssignToRenderCommandNode(IRenderCommandNode& argNode) = 0;
	virtual void UnassignFromRenderCommandNode(IRenderCommandNode& argNode) = 0;

	// Commands should be applied before all following commands
	virtual bool get_IsPreconditionForNextCommands() const = 0;

	virtual string8 get_UserName() const;
};


struct __declspec(novtable) ICommandBuffer
{
	virtual ~ICommandBuffer() {}

	virtual void Clear() = 0;

	virtual void AddCommand(Command& argCommand) = 0;

	virtual void Perform(bool argUseOptimizedList) = 0;

	virtual void Optimize() = 0;

	virtual void AddChildCommandBuffer(ICommandBuffer& argCommandBuffer) = 0;
	virtual void RemoveChildCommandBuffer(ICommandBuffer& argCommandBuffer) = 0;

	virtual std::vector<Command*>& get_BufferedCommands() = 0;

	virtual const std::vector<ICommandBuffer*>& get_ChildCommandBuffers() const = 0;

	virtual ICommandBuffer* get_ParentBuffer() const = 0;
	virtual void set_ParentBuffer(ICommandBuffer* ar_CommandBuffer_) = 0;
};