// =================================================================================================================================
/**
 * \file   index-test.c
 * \brief  Within a simulated space, fill an array and then jump to its locations, making sure its contents are correct.
 * \author Prof. Scott F. Kaplan
 * \date   Fall 2019
 **/
// =================================================================================================================================



// =================================================================================================================================
// INCLUDES

#include <assert.h>
#include <errno.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include "vmsim.h"
// =================================================================================================================================



// =================================================================================================================================
// CONSTANTS AND MACRO FUNCTIONS

/** The number of bytes in an kilobyte. */
#define BYTES_PER_KB 1024
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// =================================================================================================================================
// GLOBALS

#if !defined (IT_DEBUG)
static bool debug = false;
#else
static bool debug = true;
#endif
// =================================================================================================================================



// =================================================================================================================================
/**
 * \brief Display the proper usage and end the process with an error code.
 * \param invocation The command-line text given to run the executable.
 */
void
show_usage_and_exit (char* invocation) {

  fprintf(stderr, "USAGE: %s <size (array length of ints)>\n", invocation);
  exit(1);
  
} // show_usage_and_exit ()
// =================================================================================================================================



// =================================================================================================================================
/**
 * \brief First fill the array, then revisit a fraction of the entries randomly spots that they contain what they should.
 * \param size The number of entries in the array.
 */
void
go (unsigned int size) {

  // Use the whole real space as an array.  Initialize each entry with its own position.
  for (int i = 0; i < size; i += 1) {

    vmsim_addr_t addr = i * sizeof(i);
    vmsim_write(&i, addr, sizeof(i));

  }
  
  // Randomly select elements and checking their value.
  unsigned int reps = size;
  while (reps > 0) {

    unsigned int i = random() % size;
    unsigned int j;
    vmsim_addr_t addr = i * sizeof(i);
    vmsim_read(&j, addr, sizeof(j));
    if (i != j) {
      fprintf(stderr, "ERROR: [%d] = %d\n", i, j);
    }

    reps -= 1;

  }

} // go ()
// =================================================================================================================================



// =================================================================================================================================
/**
 * \brief The entry point to the simulator.
 * \param argc The length of the command-line argument vector.
 * \param argv The vector of command-line arguments.
 * \return the exit code for the process, where 0 indicates success, any other value indicates error.
 */
int
main (int argc, char** argv) {

  // Check usage.
  if (argc != 2) {
    show_usage_and_exit(argv[0]);
  }

  // Extract the arguments.
  errno = 0;
  unsigned int size = atoi(argv[1]);
  if (errno != 0 || size < 0) {
    show_usage_and_exit(argv[0]);
  }

  go(size);
  
  
} // main ()
// =================================================================================================================================