#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>

#include "util.h"

list_t *list_insert(list_t *next, void *data)
{
	list_t *node = new0(list_t);
	node->data = data;
	node->next = next;
	node->prev = next ? next->prev : NULL;
	if (node->next) node->next->prev = node;
	if (node->prev) node->next->next = node;
	return node;
}

list_t *list_append(list_t *head, void *data)
{
	list_t *last = head;
	while (last->next)
		last = last->next;
	list_t *node = new0(list_t);
	node->data = data;
	node->prev = last;
	if (last) last->next = node;
	return last ? head : node;
}

list_t *list_remove(list_t *head, list_t *node)
{
	list_t *next = node->next;
	list_t *prev = node->prev;
	if (next) next->prev = prev;
	if (prev) prev->next = next;
	free(node);
	return head == node ? next : head;
}

int list_length(list_t *node)
{
	int len = 0;
	for (; node; node = node->next)
		len++;
	return len;
}

void list_move(list_t *node, int offset)
{
}

/* Misc */
int error(char *fmt, ...)
{
	va_list ap;
	va_start(ap, fmt);
	fprintf(stderr, "Error: ");
	vfprintf(stderr, fmt, ap);
	fprintf(stderr, "\n");
	va_end(ap);
	exit(1);
	return 0;
}