/*
 * Copyright (c) 2008-2009 Bill Whitacre http://rampancy.g0dsoft.com
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
*/

#include "collision_filter.h"

rat_collision_filter_list *rat_collision_filter_list_create()
{
	rat_collision_filter_list *list=(rat_collision_filter_list *)rat_alloc(sizeof(rat_collision_filter_list));
	memset(list,0,sizeof(rat_collision_filter_list));

	return list;
}

void rat_collision_filter_list_destroy(rat_collision_filter_list *list)
{
	rat_collision_filter *node=list->root;
	while (node)
	{
		rat_collision_filter *next=node->next;
		rat_dealloc((void *)node);
		node=next;
	}

	rat_dealloc((void *)list);
}

static void first_add(rat_collision_filter_list *list,int tag_a,int tag_b)
{
	list->root=list->last=(rat_collision_filter *)rat_alloc(sizeof(rat_collision_filter));
	list->root->tag_a=tag_a;
	list->root->tag_b=tag_b;
	list->root->next=list->root->prev=NULL;
	list->count=1;
}

void rat_collision_filter_list_add_root(rat_collision_filter_list *list,int tag_a,int tag_b)
{
	if (list->count)
	{
		rat_collision_filter *node=(rat_collision_filter *)rat_alloc(sizeof(rat_collision_filter));
		node->tag_a=tag_a;
		node->tag_b=tag_b;
		node->prev=NULL;
		node->next=list->root;
		list->root->prev=node;
		list->root=node;
		list->count++;
	}
	else
		first_add(list,tag_a,tag_b);
}

void rat_collision_filter_list_add_last(rat_collision_filter_list *list,int tag_a,int tag_b)
{
	if (list->count)
	{
		rat_collision_filter *node=(rat_collision_filter *)rat_alloc(sizeof(rat_collision_filter));
		node->tag_a=tag_a;
		node->tag_b=tag_b;
		node->prev=list->last;
		node->next=NULL;
		list->last->next=node;
		list->last=node;
		list->count++;
	}
	else
		first_add(list,tag_a,tag_b);
}

int rat_collision_filter_list_remove_root(rat_collision_filter_list *list,int tag_a,int tag_b)
{
	rat_collision_filter *node;
	for (node=list->root; node; node=node->next)
	{
		if ((node->tag_a==tag_a&&node->tag_b==tag_b)||
			(node->tag_a==tag_b&&node->tag_b==tag_a))
		{
			if (node->next) node->next->prev=node->prev;
			if (node->prev) node->prev->next=node->next;
			
			if (!(--list->count))
			{
				list->root=NULL;
				list->last=NULL;
			}
			rat_dealloc((void *)node);
			return 1;
		}
	}

	return 0;
}

int rat_collision_filter_list_remove_last(rat_collision_filter_list *list,int tag_a,int tag_b)
{
	rat_collision_filter *node;
	for (node=list->last; node; node=node->prev)
	{
		if ((node->tag_a==tag_a&&node->tag_b==tag_b)||
			(node->tag_a==tag_b&&node->tag_b==tag_a))
		{
			if (node->next) node->next->prev=node->prev;
			if (node->prev) node->prev->next=node->next;
			
			if (!(--list->count))
			{
				list->root=NULL;
				list->last=NULL;
			}
			rat_dealloc((void *)node);
			return 1;
		}
	}

	return 0;
}

void rat_collision_filter_list_clear(rat_collision_filter_list *list)
{
	rat_collision_filter *node=list->root;
	while (node)
	{
		rat_collision_filter *next=node->next;
		rat_dealloc((void *)node);
		node=next;
	}

	list->root=NULL;
	list->last=NULL;
	list->count=0;
}

int rat_collision_filter_list_hit(rat_collision_filter_list *list,int tag_a,int tag_b)
{
	rat_collision_filter *node;
	for (node=list->root; node; node=node->next)
	{
		if ((node->tag_a==tag_a&&node->tag_b==tag_b)||
			(node->tag_a==tag_b&&node->tag_b==tag_a))
			return 1;
	}
	return 0;
}