/*
 * File:
 *   stubdata.c
 * Author:
 *   Samuel A. Rebelsky
 * Version:
 *   0.1 of July 2003
 * Summary:
 *   Procedures and variables used to generate a simulated set
 *   of visits.  See clio.h for details.
 */

/*********************************************************************
 * Headers *
 ***********/

#include "clio.h"
#include <time.h>	/* I use time() to seed the generator. */
#include <limits.h>	/* I use INT_MAX. */


/*********************************************************************
 * Constants *
 *************/

/* The maximum number of page ids. */
#define MAXPAGE 100

/* The maximum length of a visit (in seconds). */
#define MAXLENGTH 100


/*********************************************************************
 * Variables *
 *************/

pagevisit *visits = NULL;
int numvisits = 0;
int starttime = 0;
int endtime = 0;
int pagetypes = 0; 
int maxlength = 0;


/*********************************************************************
 * Local Functions *
 *******************/

/*
 * Compute a random value between 0 and max-1.
 */
int
restrictedRand(int max)
{
  return (int) ((((float) max)*rand())/(RAND_MAX+1.0));
} /* restrictedRand(int) */


/*********************************************************************
 * Exported Functions *
 **********************/

void 
loadData(selector *query)
{
  int i;	/* Counter variable. */

  /* Prepare to generate random numbers. */
  srand(time(NULL));

  /* 
   * Figure out how many visits there will be.  I decided 20 to 50
   * is a good starting point. 
   */
  numvisits = 20 + restrictedRand(30);
  fprintf(stderr, "Creating %d visits.\n", numvisits);

  /*
   * Set up preliminary information on all the visits.  This
   * information will change as we fill in the visits.
   */
  starttime = INT_MAX;
  endtime = 0;
  maxlength = 0;
  pagetypes = 0;

  /* Clear the old visits, if they're set. */
  if (visits != NULL) { free(visits); }
 
  /* Allocate memory for the visits.  No error checking here. */
  visits = (pagevisit *) malloc(numvisits * sizeof(pagevisit));

  /* Set up all the visits. */
  for (i = 0; i < numvisits; i++) {
    visits[i].visitid = i;
    visits[i].userid = restrictedRand(3);
    visits[i].pageid = restrictedRand(MAXPAGE);
    visits[i].windowid = restrictedRand(3);
    visits[i].sessionid = restrictedRand(3);
    visits[i].uws = restrictedRand(10);
    visits[i].start = restrictedRand(1000);
    visits[i].length = restrictedRand(MAXLENGTH);
    visits[i].type = restrictedRand(5);
    if (visits[i].start < starttime) {
      starttime = visits[i].start;
    }
    if ((visits[i].start + visits[i].length) > endtime) {
      endtime = visits[i].start + visits[i].length;
    }
    if (visits[i].length > maxlength) {
      maxlength = visits[i].length;
    }
    if (visits[i].type > pagetypes) {
      pagetypes = visits[i].type;
    }
  } /* for */

  /* That's it, we're done. */
} /* loadData() */