#include <stdio.h>

#include "observer.h"

#include <stdlib.h>
void *xmalloc (size_t size) { return malloc (size); }
void xfree (void *ptr) { free (ptr); }
void warning (const char *str, ...) { printf ("warning: %s.\n", str); }

int first_observer = 0;
int second_observer = 0;
int third_observer = 0;

void
reset_counters (void)
{
  first_observer = 0;
  second_observer = 0;
  third_observer = 0;
}

void
check_counters (int first, int second, int third)
{
  if (first_observer != first)
    printf ("ERROR: first observer incorrect count: %d (expected %d).\n",
            first_observer, first);
  if (second_observer != second)
    printf ("ERROR: second observer incorrect count: %d (expected %d).\n",
            second_observer, second);
  if (third_observer != third)
    printf ("ERROR: third observer incorrect count: %d (expected %d).\n",
            third_observer, third);
}

void
test_notifications (int first, int second, int third, char *msg)
{
  printf ("--  Sending notification (%s)...\n", msg);
  reset_counters ();
  observer_notify_normal_stop ();
  check_counters (first, second, third);
}

void
first_observer_notification (void)
{
  first_observer++;
}

void
second_observer_notification (void)
{
  second_observer++;
}

void
third_observer_notification (void)
{
  third_observer++;
}

void
general_observer_test (void)
{
  struct observer *first_obs = NULL;
  struct observer *second_obs = NULL;
  struct observer *third_obs = NULL;

  /* First, try sending a notification without any observers attached.  */
  test_notifications (0, 0, 0, "no observer");

  /* Now, attach one observer, and send a notification.  */
  second_obs = observer_attach_normal_stop (&second_observer_notification);
  test_notifications (0, 1, 0, "one observer");
  
  /* Remove the observer, and send a notification.  */
  observer_detach_normal_stop (second_obs);
  test_notifications (0, 0, 0, "no observer");

  /* With a new observer.  */
  first_obs = observer_attach_normal_stop (&first_observer_notification);
  test_notifications (1, 0, 0, "a new observer");

  /* With 2 observers.  */
  second_obs = observer_attach_normal_stop (&second_observer_notification);
  test_notifications (1, 1, 0, "2 observers");

  /* With 3 observers.  */
  third_obs = observer_attach_normal_stop (&third_observer_notification);
  test_notifications (1, 1, 1, "3 observers");

  /* Remove the middle observer.  */
  observer_detach_normal_stop (second_obs);
  test_notifications (1, 0, 1, "middle observer removed");

  /* Remove first observer.  */
  observer_detach_normal_stop (first_obs);
  test_notifications (0, 0, 1, "first observer removed");

  /* Remove last observer.  */
  observer_detach_normal_stop (third_obs);
  test_notifications (0, 0, 0, "last observer removed");

  /* Go back to 3 observers, and remove them in a different order...  */
  first_obs = observer_attach_normal_stop (&first_observer_notification);
  second_obs = observer_attach_normal_stop (&second_observer_notification);
  third_obs = observer_attach_normal_stop (&third_observer_notification);
  test_notifications (1, 1, 1, "3 observers");

  /* Remove the third observer... */
  observer_detach_normal_stop (third_obs);
  test_notifications (1, 1, 0, "third observer removed");

  /* Remove the second observer... */
  observer_detach_normal_stop (second_obs);
  test_notifications (1, 0, 0, "second observer removed");

  /* Remove the first observer...  No more observers.   */
  observer_detach_normal_stop (first_obs);
  test_notifications (0, 0, 0, "first observer removed - no more observers");

}

int
main (void)
{
  general_observer_test ();
  return 0;
}