#ifndef TELNET_HANDLER__H_
#define TELNET_HANDLER__H_

#ifdef _WIN32
#pragma once
#endif


class HTelnetHandler : public HProtocolHandler
{
public:
	enum eCommand
	{
		SE		= 240,	// End of subnegotiation parameters.
		NOP		= 241,	// No operation Data mark. Indicates the position of a Synch event within the data stream.
		DM		= 242,	// This should always be accompanied by a TCP urgent notification.
		BRK		= 243,	// Break. Indicates that the "break" or "attention" key was hit.
		IP		= 244,	// Suspend, interrupt or abort the process to which the NVT is connected.
		AO		= 245,	// Abort output. Allows the current process to run to completion but donot send its output to the user.
		AYT		= 246,	// Are you there. Send back to the NVT some visible evidence that the AYT was received.
		EC		= 247,	// Erase character. The receiver should delete the last preceding undeleted character from the data stream.
		EL		= 248,	// Erase line. Delete characters from the data stream back to but not including the previous CRLF.
		GA		= 249,	// Go ahead. Used, under certain circumstances, to tell the other end that it can transmit.
		SB		= 250,	// Subnegotiation of the indicated option follows.
		WILL	= 251,	// Indicates the desire to begin performing, or confirmation that you are now performing, the indicated option.
		WONT	= 252,	// Indicates the refusal to perform, or continue performing, the indicated option. 
		DO		= 253,	// Indicates the request that the other party perform, or confirmation that you are expecting the other party to perform, the indicated option.    
		DONT	= 254,	// Indicates the demand that the other party stop performing, or confirmation that you are no longer expecting the other party to perform, the indicated option.
		IAC		= 255	// Interpret as command.
	};
	
	enum EOption
	{
		ECHO		= 1,	// echo (RFC 857)
		SGAHEAD		= 3,	// suppress go ahead (RFC 858)
		STATUS		= 5,	// status (RFC 859)
		TMARK		= 6,	// timing mark (RFC 860)
		TTYPE		= 24,	// terminal type (RFC 1091)
		WSIZE		= 31,	// window size (RFC 1073)
		TSPEED		= 32,	// terminal speed (RFC 1079)
		RFCONTROL	= 33,	// remote flow control (RFC 1372)
		LMODE		= 34,	// linemode (RFC 1184)
		EVARIABLES	= 36,	// environment variables (RFC 1408)
	};
	
	enum
	{
		MAX_COMMAND_BUFFER_SIZE = 4096
	};

	HTelnetHandler();
	~HTelnetHandler();

protected:
	void OnReceivedStatusFromTransport(int nStatus);
	int OnReceivedFromTransport(const char * pData, int nSize);

	virtual void OnEstablished() {}
	virtual bool OnInitialReceive(const char * pData, unsigned nSize) { return true; }
	virtual int OnReceivedCommand(const char * pszCommand) = 0;

protected:
	char m_pCommandBuffer[MAX_COMMAND_BUFFER_SIZE + 1];
	unsigned int m_nCommandBufferedLength;

	int m_bInitialStep;
};


#endif	// PROTOCOL_HANDLER__H_