/* SMRT (Single Message Round trip Time Measurement)
*/
#include "smrt.h"
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <time.h>
#include <stddef.h>
#include <stdlib.h>

/***** FUNCTION PROTOTYPES *****/

FILE *OpenFile(char *fname, char *access_mode);
void HoldScreen(void);

/***** PROGRAM's MAIN DRIVER *****/

main(argc,argv)
int argc;
char *argv[];
{
  FILE *OUTFILE;
  FILE *Ifile;
  FILE *RFile;
  char sitename[100];
  char Ln[300];
  char PingInstruction[200];  
  float min=0,average=0,max=0;
  float bandwidth;	// available bandwidth
  float times;	// round trip time
  int sitenum=0;
  int i=0;
  int FindOrNot=0;

  Ifile = OpenFile(argv[1], "r");
  while (fscanf(Ifile,"%s %f %f\n",sitename,&bandwidth,&times) != EOF)
  {	
	  if (strcmp(sitename,argv[2]) == 0)	{
		strcpy(PingInstruction,"");
		strcat(PingInstruction,"ping -c 1 ");
		strcat(PingInstruction,sitename);
		strcat(PingInstruction," > SMRTping.txt");
		
		//printf("%s\n",PingInstruction);
		system(PingInstruction); 
		RFile = OpenFile("SMRTping.txt", "r");
	
		// read the ping result file
		while (fgets(Ln,255,RFile) != EOF)
		{
			if (strstr(Ln,"packet loss") != NULL) 
			{
				float band=0;

				fscanf(RFile,"%*s  %*s = %f/%f/%f ", &min, &average, &max);
								
				if (average <= times)
					band = bandwidth;	
				else
					band = (bandwidth*times)/average;
	
				printf("%s %f\n","Available Bandwidth is :",band);
            
				break;
			}
		}// end of ping text file while	
		fclose(RFile);
		FindOrNot=1;
		break;
	  } // end if	  
  } // end of siteList file while
			

  fclose(Ifile); 
  if (!FindOrNot)
	printf("Did not find the history information of entried host name !!!\n");

  return 1;
} /* end main() */

/***** FUNCTION DEFINITIONS ******/  

/* This funcction returns a pointer to the opened file named as a the 1st */
/* argument for the access mode of the second argument. */
FILE *OpenFile( char *fname, char *access_mode)
{
  FILE *fp;

  if((fp=fopen(fname, access_mode)) == NULL)
    fprintf(stderr,"\nError openong file %s with access mode %s\n",
      fname, access_mode);
  return fp;
} /* OpenFile */

/* Prompts the user to press Enter to continue program execution. */
void HoldScreen(void)
{
  int dummy;
  
  printf("\nPress Enter to continue: ");
  fflush(stdin);
  dummy = getchar();
  printf("%c\n",dummy);
} /* HoldScreen */