/* This program was written from information conained in the document
 * "TCP Remote Protocol, version 1.1" located at:

http://www.tivo.com/assets/images/abouttivo/resources/downloads/brochures/TiVo_TCP_Network_Remote_Control_Protocol.pdf

*/

#include <winsock2.h>
#include <stdio.h>

/* The buffer to hold the responses from the TiVo */
static char responseData[1024];

/* This function will abstract the differences in sleeping among various OSes */
static void sleep( int milliSeconds )
{
    #ifdef _WIN32
            Sleep( milliSeconds );
#else
            usleep( milliSeconds * 1000 );
#endif

} /* end sleep */


/* This function will wait for the response from the TiVo */
static void waitForResponse( unsigned tivoSocket )
{
	/* the number of bytes received into the buffer */
    int receiveCount = 0;

	/* a counter for the loops to determine if I should give up */
    int timeoutCount = 0;

	/* the max number of iterations before giving up */
    const int timeoutLimit = 20;

	/* clear out the response buffer so I can use it to print the responses */
    memset( responseData, 0, sizeof(responseData) );

    /* while there is more data toreceive, and I haven't wated too long */
    while (((receiveCount == 0) || 
            (responseData[receiveCount -1] != '\r')) &&
           !(timeoutCount > timeoutLimit))
    {
		/* the number of bytes received from the "recv" call */
        int receiveBytes;

		/* count this iteration */
        timeoutCount += 1;
        
		/* try to receive data */
        receiveBytes = recv( tivoSocket, 
			                 &responseData[receiveCount], 
			                 sizeof( responseData ), 0 );

		/* if there were no bytes received */
        if (receiveBytes <= 0)
        {
            sleep( 50 );
        }
        else
        {
			/* count the number of bytes the buffer has */
            receiveCount += receiveBytes;
        }
    }

	/* print the data that was received from the TiVo */
    puts(responseData);

} /* end waitForResponse */


int main( int argc, char *argv[])
{
	struct hostent *hostAddr;
	struct in_addr inAddr;
	struct sockaddr_in tivoAddr;

	unsigned int tivoSocket;

	short tivoPort = htons( 31339 );

#if defined(_WIN32)
	WORD winsockVersion = MAKEWORD(2, 2);
	WSADATA startupData;
#endif

	int nonblocking;
	int result;

#if defined(_WIN32)
	(void) WSAStartup(winsockVersion, &startupData);
#endif

	hostAddr = gethostbyname(argv[1]);

	tivoPort = htons(31339);
	
	inAddr.s_addr = *(ULONG *) hostAddr->h_addr_list[0];

	// create the socket
	tivoSocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);

	// define the TiVo side connection
	memset(&tivoAddr, 0, sizeof(tivoAddr));
	tivoAddr.sin_addr.S_un.S_addr = inAddr.S_un.S_addr;
	tivoAddr.sin_port = tivoPort;
	tivoAddr.sin_family = AF_INET;

	// connect to the TiVo
	result = connect( tivoSocket, (void *)&tivoAddr, sizeof( tivoAddr ) );

	// if the connection was established
	if (result >= 0)
	{
        char tivoCommand[80];
        int i;

        nonblocking = 1;

        result = ioctlsocket( tivoSocket,
                              FIONBIO,
                              (void *)&nonblocking );

        waitForResponse( tivoSocket );

    	// send the command to go to LIVETV
        (void) sprintf( tivoCommand, "%s\r", "TELEPORT LIVETV" );
        (void) send( tivoSocket, tivoCommand, strlen( tivoCommand ), 0 );

    	/* wait so the response will be ready */
        waitForResponse( tivoSocket );

    	// record the command and response to the log file

    	/* send the command to change the channel */
        for (i = 0; i < strlen( argv[2] ); i++)
        {
            (void) sprintf( tivoCommand, "KEYBOARD NUM%c\r", argv[2][i] );
            puts(tivoCommand);
            (void) send( tivoSocket, tivoCommand, strlen( tivoCommand ), 0 );
        }
        
        /* send the ENTER command so I won't have to wait for the timeout
         * period 
         */
        (void) sprintf( tivoCommand, "KEYBOARD %s\r", "ENTER" );
        (void) send( tivoSocket, tivoCommand, strlen( tivoCommand ), 0 );

    	// The KEYBOARD commands don't have a response

        /* wait a little bit so the channel will be tuned, otherwise the
         * CLEAR command will be ignored
         */
        sleep( 500 );

    	// send the command to clear the overlay from the screen
        (void) sprintf( tivoCommand, "%s\r", "KEYBOARD CLEAR" );
        (void) send( tivoSocket, tivoCommand, strlen( tivoCommand ), 0 );

        // The KEYBOARD commands don't have a response

	    // close the socket
#if defined(_WIN32)
        closesocket( tivoSocket );
#else
	    close( tivoSocket );
#endif
	}
    printf( "%d\n", WSAGetLastError());

	return 0;
}