/*
    CrossFire, A Multiplayer game for X-windows

    Copyright (C) 2002 Mark Wedel & Crossfire Development Team
    Copyright (C) 1992 Frank Tore Johansen

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

    The authors can be reached via e-mail at <crossfire@schmorp.de>
*/

#include <global.h>

/*
 * Add a new friendly object to the linked list of friendly objects.
 * No checking to see if the object is already in the linked list is done.
 */

void
add_friendly_object (object *op)
{
  objectlink *ol;

  /* Add some error checking.  This shouldn't happen, but the friendly
   * object list usually isn't very long, and remove_friendly_object
   * won't remove it either.  Plus, it is easier to put a breakpoint in
   * the debugger here and see where the problem is happening. 
   */
  for (ol = first_friendly_object; ol != NULL; ol = ol->next)
    {
      if (ol->ob == op)
        {
          LOG (llevError, "add_friendly_object: Trying to add object already on list (%s)\n", &op->name);
          return;
        }
    }

  ol = first_friendly_object;
  first_friendly_object = get_objectlink ();
  first_friendly_object->ob = op;
  first_friendly_object->id = op->count;
  first_friendly_object->next = ol;
}

/*
 * Removes the specified object from the linked list of friendly objects.
 */

void
remove_friendly_object (object *op)
{
  objectlink *obj;

  CLEAR_FLAG (op, FLAG_FRIENDLY);

  if (!first_friendly_object)
    {
      LOG (llevError, "remove_friendly_object called with empty friendly list, remove ob=%s\n", &op->name);
      return;
    }
  /* if the first object happens to be the one, processing is pretty
   * easy.
   */
  if (first_friendly_object->ob == op)
    {
      obj = first_friendly_object;
      first_friendly_object = obj->next;
      free (obj);
    }
  else
    {
      objectlink *prev = first_friendly_object;

      for (obj = first_friendly_object->next; obj != NULL; obj = obj->next)
        {
          if (obj->ob == op)
            break;
          prev = obj;
        }
      if (obj)
        {
          /* This should not happen.  But if it does, presumably the
           * call to remove it is still valid.
           */
          if (obj->id != op->count)
            {
              LOG (llevError, "remove_friendly_object, tags do no match, %s, %d != %d\n",
                   op->name ? (const char *) op->name : "none", op->count, obj->id);
            }
          prev->next = obj->next;
          free (obj);
        }
    }
}

/*
 * Dumps all friendly objects.  Invoked in DM-mode with the G key.
 */

void
dump_friendly_objects (void)
{
  objectlink *ol;

  for (ol = first_friendly_object; ol != NULL; ol = ol->next)
    LOG (llevError, "%s (%d)\n", &ol->ob->name, ol->ob->count);
}

/* New function, MSW 2000-1-14
 * It traverses the friendly list removing objects that should not be here
 * (ie, do not have friendly flag set, freed, etc)
 */
void
clean_friendly_list (void)
{
  objectlink *obj, *prev = NULL, *next;
  int count = 0;

  for (obj = first_friendly_object; obj != NULL; obj = next)
    {
      next = obj->next;
      if (QUERY_FLAG (obj->ob, FLAG_FREED) || !QUERY_FLAG (obj->ob, FLAG_FRIENDLY) || (obj->id != obj->ob->count))
        {
          if (prev)
            {
              prev->next = obj->next;
            }
          else
            {
              first_friendly_object = obj->next;
            }
          count++;
          free (obj);
        }
      /* If we removed the object, then prev is still valid.  */
      else
        prev = obj;
    }
  if (count)
    LOG (llevDebug, "clean_friendly_list: Removed %d bogus links\n", count);
}

/* Checks if the given object is already in the friendly list or not
 * Lauwenmark - 31/07/05
 */
int
is_friendly (const object *op)
{
  objectlink *ol;

  for (ol = first_friendly_object; ol != NULL; ol = ol->next)
    if (ol->ob == op)
      return 1;

  return 0;
}