/*
 * Copyright 2010 Andrea Mazzoleni. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY ANDREA MAZZOLENI AND CONTRIBUTORS ``AS IS''
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL ANDREA MAZZOLENI OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include "tommylist.h"
#include "tommychain.h"

void tommy_list_concat(tommy_list* first, tommy_list* second)
{
	tommy_node* first_head;
	tommy_node* first_tail;
	tommy_node* second_head;

	if (tommy_list_empty(second)) {
		return;
	}

	if (tommy_list_empty(first)) {
		*first = *second;
		return;
	}

	first_head = tommy_list_head(first);
	second_head = tommy_list_head(second);
	first_tail = tommy_list_tail(first);

	/* set the "circular" prev list */
	first_head->prev = second_head->prev;
	second_head->prev = first_tail;

	/* set the "0 terminated" next list */
	first_tail->next = second_head;
}

/** \internal
 * Setup a list.
 */
tommy_inline void tommy_list_set(tommy_list* list, tommy_node* head, tommy_node* tail)
{
	head->prev = tail;
	tail->next = 0;
	*list = head;
}

void tommy_list_sort(tommy_list* list, tommy_compare_func* cmp)
{
	tommy_chain chain;
	tommy_node* head;

	if (tommy_list_empty(list))
		return;

	head = tommy_list_head(list);

	/* create a chain from the list */
	chain.head = head;
	chain.tail = head->prev;

	tommy_chain_mergesort(&chain, cmp);

	/* restore the list */
	tommy_list_set(list, chain.head, chain.tail);
}