/*
 * static char *rcsid_friend_c =
 *   "$Id: friend.c 11578 2009-02-23 22:02:27Z lalo $";
 */

/*
    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-devel@real-time.com
*/

/**
 * @file friend.c
 * Functions related to relationship management.
 */

#include <global.h>

/**
 * Add a new friendly object to the linked list of friendly objects.
 * Will log an error if the object is already on that list.
 *
 * @param op
 * object to add to the list.
 */
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.
     */
    if (is_friendly(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.
 *
 * @param op
 * object to remove from list.
 */
void remove_friendly_object(object *op) {
    objectlink *this;

    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) {
        this = first_friendly_object;
        first_friendly_object = this->next;
        free(this);
    } else {
        objectlink *prev = first_friendly_object;

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

/**
 * Dumps all friendly objects.  Invoked in DM-mode with dumpfriendlyobjects command.
 *
 * @note
 * logs at the error level.
 */
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);
}

/**
 * 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 *this, *prev = NULL, *next;
    int count = 0;

    for (this = first_friendly_object; this != NULL; this = next) {
        next = this->next;
        if (QUERY_FLAG(this->ob, FLAG_FREED)
        || !QUERY_FLAG(this->ob, FLAG_FRIENDLY)
        || (this->id != this->ob->count)) {
            if (prev) {
                prev->next = this->next;
            } else {
                first_friendly_object = this->next;
            }
            count++;
            free(this);
        /* If we removed the object, then prev is still valid.  */
        } else
            prev = this;
    }
    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
 *
 * @param op
 * item to check
 * @return
 * 1 if on friendly list, 0 else
 */
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;
}