/************************************************************************
 * Boston University
 * CS 555 -- Fall 2003
 *
 * The interfaces for the SRMP sender (you get to implement them), and a 
 * simple application-level routine to drive the sender.  
 *
 * This routine reads the data to be transferred over the connection
 * from a file specified and invokes the SRMP send functionality to 
 * deliver the packets as an ordered sequence of datagrams.
 *
 * Version 1.0 
 * 
 *
 *************************************************************************/


#include <stdio.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/file.h>

#include "srmp.h"

#define  SRMP_ERROR -1

typedef struct{

     int DELETE_ME;     /* used only to make this compile */

     /* YOUR CODE HERE */

}srmp_send_ctrl_blk;



/* YOUR CODE HERE (if needed) */


/*
 * Send a message using SRMP.
 * The main entry point to the (not yet implemented) sender-side of the protocol.
 */
int
srmp_send (srmp_send_ctrl_blk *srmp_CB, char* data, int len)
{
	/* YOUR CODE HERE */
}



/*
 * Open the sender side of the SRMP connection.  
 * 
 */
int
srmp_open(srmp_send_ctrl_blk * srmp_CB, char *dst, int sport, int rport)
{

    /* YOUR CODE HERE */
}


/*
 * Close the sender side of the SRMP connection after all data transmitted.
 *
 */
int
srmp_close(srmp_send_ctrl_blk *srmp_CB)
{
    /* YOUR CODE HERE */
}


/***************************************************************/
/* This application is to invoke the send-side functionality.  */
/* Feel free to rewrite or write your own application to       */
/* test your code.                                             */
/*                                                             */
/***************************************************************/
int
main(int argc, char **argv)
{
    srmp_send_ctrl_blk *srmp_CB;

    char     * dst;
    int      recv_port, send_port;
    int      file;
    int      ret_val;

    /* Verify that the arguments are right*/
    if (argc != 5) {
        fprintf(stderr, "usage: SendApp receiver-IP-address recv-port send-port filename \n");
        exit(1);
    }

    /************************************************************/
    /*                                                          */
    /* Open connection to destination.  If srmp_open succeeds   */
    /* the srmp_CB should be correctly initialized              */
    /*                                                          */
    /************************************************************/

    srmp_CB = (srmp_send_ctrl_blk *) malloc (sizeof( *srmp_CB));
    dst = argv[1];
    recv_port = atoi(argv[2]);
    send_port = atoi(argv[3]);

    ret_val = srmp_open(srmp_CB, dst, send_port, recv_port);
    if( ret_val == SRMP_ERROR ) 
    {
        /* YOUR CODE HERE */
    }

    /************************************************************/
    /*                                                          */
    /* Open file for transfer                                   */             
    /*                                                          */
    /************************************************************/
    file = open(argv[4], O_RDONLY);
    if (file < 0) 
    {
        perror(argv[4]);
        exit(1);
    }

    /************************************************************/
    /*                                                          */
    /* Start to send data in file via SRMP to remote receiver   */
    /*                                                          */
    /************************************************************/

    /************************************************************/
    /*                                                          */
    /* Chop up the file into pieces half as large as max        */
    /* packet size ...  and transmit those pieces.              */
    /*                                                          */
    /************************************************************/
    while(1)
    {
        char wrk[SRMP_MAXPKT / 2];
        int cc = read(file, wrk, sizeof(wrk));

        /* Break when EOF is reached */
        if(cc <= 0)
            break;

        if(srmp_send(srmp_CB, wrk, cc) == SRMP_ERROR) 
        {
            /* YOUR CODE HERE */
        }
    }

    /************************************************************/
    /*                                                          */
    /* Close the connection to remote receiver                  */
    /*                                                          */
    /************************************************************/   
    if (srmp_close(srmp_CB) == SRMP_ERROR) 
    {
        /* YOUR CODE HERE */
    }
    return 0;
}