#include <stdio.h>
#include <stdlib.h>

int main(int argc, char *argv[])
{
  FILE *fin, *fout, *fout2;
  int pkt_index[1000]; 
  double pkt_send_time[1000];
  int head;
  //int tail;
  /* make sure it is large enough to hold all temprary data! */
  int i,j,num;
  double tm, tm_delay, total_delay, avg_delay, var_delay;
  int idx;
  char type;
  int flag;
  int num_sent;
  
  head = 0;
  for ( i=0; i<1000; i++)
  {
     pkt_index[i]  = -1;
     pkt_send_time[i] = 0.0f;
  }
  
  fin = fopen(argv[1], "r");
  fout = fopen (argv[2], "w");
  fout2 = fopen ( argv[3],"a");
  
  if(fin==NULL) {
    printf("Error: can't open file.\n");
    return 1;
  }
  else {
    printf("File opened successfully.\n");

    i = 0 ;  
    num  = 0;  
    num_sent = 0;
    while(!feof(fin)) 
    { 
      /* loop through and store the numbers into the array */
      fscanf(fin, "%c %lf %d \n", &type,&tm, &idx);
      //printf( "%f\n", tm);
      
	if ( type == 's' )
	{
		//addentry(idx, tm);
		pkt_index[head] = idx;
		pkt_send_time[head] = tm;
		head++;
		if ( head == 1000 ) head = 0;
		num_sent++;
       
       
	}
	else if ( type == 'r' )
	{
		flag = 0;
		for ( j=0; j< 1000; j++)
		{
      
			if (  pkt_index[j] == idx )
			{
			//printf("match,%f, %f\n!" ,tm, pkt_send_time[j]);
			tm_delay =  tm - pkt_send_time[j];
			flag = 1;
			break;
			} 
		}
		//addentry to output
		if ( flag == 1)
		{
		fprintf( fout,"%d %lf \n", idx, tm_delay ); 
		total_delay += tm_delay;    
		num++;
		}
	}

      i++;
    }
    avg_delay = total_delay / num ;
    fprintf(fout2,"Number of entries read: %d\n", i);
    fprintf(fout2,"Number of entries sent: %d\n", num_sent);
    fprintf(fout2,"Number of entries received:  %d\n", num);
    fprintf(fout2,"average delay of entries :  %lf\n", avg_delay);
    
    fclose(fin);
    fclose(fout);
  
    
    //finally, calcualte variance
    fout = fopen ( argv[2], "r") ;
    if ( fout == NULL ) return -1;
    var_delay = 0;
    while (!feof(fout))
    {
       fscanf(fout, "%d %lf\n", &idx ,&tm);
       var_delay += ( tm - avg_delay  ) * (tm - avg_delay);    
    }
    var_delay /= num;	    
    fprintf(fout2, "variance of  delay is :  %lf\n", var_delay);
    fclose (fout);
    fclose (fout2);
	   
    return 0;
  }
  
  
  
}