/* sdb - MIT - Copyright 2007-2014 - pancake */

#include <string.h>
#include "ls.h"

SDB_API SdbList *ls_new() {
	SdbList *list = R_NEW (SdbList);
	if (!list)
		return NULL;
	list->head = NULL;
	list->tail = NULL;
	list->free = free; // HACK
	list->length = 0;
	return list;
}

SDB_API void ls_sort(SdbList *list, SdbListComparator cmp) {
	SdbListIter *it, *it2;
	for (it = list->head; it && it->data; it = it->n) {
		for (it2 = it->n; it2 && it2->data; it2 = it2->n) {
			if (cmp (it->data, it2->data)>0) {
				void *t = it->data;
				it->data = it2->data;
				it2->data = t;
			}
		}
	}
}

SDB_API void ls_delete (SdbList *list, SdbListIter *iter) {
	if (!list || !iter) return;
	ls_split_iter (list, iter);
	if (list->free && iter->data) {
		list->free (iter->data);
		iter->data = NULL;
	}
	free (iter);
	list->length--;
}

SDB_API void ls_split_iter (SdbList *list, SdbListIter *iter) {
	if (!list || !iter) return;
	if (list->head == iter) list->head = iter->n;
	if (list->tail == iter) list->tail = iter->p;
	if (iter->p) iter->p->n = iter->n;
	if (iter->n) iter->n->p = iter->p;
}

SDB_API void ls_destroy (SdbList *list) {
	SdbListIter *it;
	if (!list) return;
	it = list->head;
	while (it) {
		SdbListIter *next = it->n;
		ls_delete (list, it);
		it = next;
	}
	list->head = list->tail = NULL;
	list->length = 0;
}

SDB_API void ls_free (SdbList *list) {
	if (!list) return;
	ls_destroy (list);
	list->free = NULL;
	free (list);
}

SDB_API SdbListIter *ls_append(SdbList *list, void *data) {
	SdbListIter *it;
	if (!list)
		return NULL;
	it = R_NEW (SdbListIter);
	if (!it)
		return NULL;
	if (list->tail)
		list->tail->n = it;
	it->data = data;
	it->p = list->tail;
	it->n = NULL;
	list->tail = it;
	if (list->head == NULL)
		list->head = it;
	list->length++;
	return it;
}

SDB_API SdbListIter *ls_prepend(SdbList *list, void *data) {
	SdbListIter *it = R_NEW (SdbListIter);
	if (!it) return NULL;
	if (list->head)
		list->head->p = it;
	it->data = data;
	it->n = list->head;
	it->p = NULL;
	list->head = it;
	if (list->tail == NULL)
		list->tail = it;
	list->length++;
	return it;
}

SDB_API void *ls_pop(SdbList *list) {
	void *data = NULL;
	SdbListIter *iter;
	if (list){
		if (list->tail) {
			iter = list->tail;
			if (list->head == list->tail) {
				list->head = list->tail = NULL;
			} else {
				list->tail = iter->p;
				list->tail->n = NULL;
			}
			data = iter->data;
			free (iter);
			list->length--;
		}
		return data;
	}
	return NULL;
}