#include "list.h"

#include <blue/ds/list.h>
#include <stdlib.h>
#include <string.h>

static void list_release(struct b_dsref *obj);

static struct b_dsref_type list_type = {
	.t_name = "corelib::list",
	.t_flags = B_DSREF_FUNDAMENTAL,
	.t_id = B_DSREF_TYPE_LIST,
	.t_instance_size = sizeof(struct b_list),
	.t_release = list_release,
};

struct b_list *b_list_create(void)
{
	struct b_list *list
		= (struct b_list *)b_dsref_type_instantiate(&list_type);
	if (!list) {
		return NULL;
	}

	return list;
}

bool b_list_empty(struct b_list *q)
{
	return q->l_len == 0;
}

void *b_list_first_item(const struct b_list *q)
{
	struct b_queue_entry *entry = b_queue_first(&q->l_queue);

	if (!entry) {
		return NULL;
	}

	struct b_list_entry *list_entry
		= b_unbox(struct b_list_entry, entry, e_entry);

	return list_entry->e_data;
}

void *b_list_last_item(const struct b_list *q)
{
	struct b_queue_entry *entry = b_queue_last(&q->l_queue);

	if (!entry) {
		return NULL;
	}

	struct b_list_entry *list_entry
		= b_unbox(struct b_list_entry, entry, e_entry);

	return list_entry->e_data;
}

struct b_list_entry *b_list_first_entry(const struct b_list *q)
{
	struct b_queue_entry *entry = b_queue_first(&q->l_queue);

	if (!entry) {
		return NULL;
	}

	struct b_list_entry *list_entry
		= b_unbox(struct b_list_entry, entry, e_entry);

	return list_entry;
}

struct b_list_entry *b_list_last_entry(const struct b_list *q)
{
	struct b_queue_entry *entry = b_queue_last(&q->l_queue);

	if (!entry) {
		return NULL;
	}

	struct b_list_entry *list_entry
		= b_unbox(struct b_list_entry, entry, e_entry);

	return list_entry;
}

struct b_list_entry *b_list_next(const struct b_list_entry *entry)
{
	if (!entry) {
		return NULL;
	}

	struct b_queue_entry *next = b_queue_next(&entry->e_entry);

	if (!next) {
		return NULL;
	}

	return b_unbox(struct b_list_entry, next, e_entry);
}

struct b_list_entry *b_list_prev(const struct b_list_entry *entry)
{
	if (!entry) {
		return NULL;
	}

	struct b_queue_entry *next = b_queue_prev(&entry->e_entry);

	if (!next) {
		return NULL;
	}

	return b_unbox(struct b_list_entry, next, e_entry);
}

size_t b_list_length(const struct b_list *q)
{
	return q->l_len;
}

static struct b_list_entry *make_entry(void *item)
{
	struct b_list_entry *entry = malloc(sizeof *entry);
	if (!entry) {
		return NULL;
	}

	memset(entry, 0x0, sizeof *entry);

	entry->e_data = item;

	return entry;
}

struct b_list_entry *b_list_insert_before(
	struct b_list *q, void *ptr, struct b_list_entry *before)
{
	struct b_list_entry *entry = make_entry(ptr);
	if (!entry) {
		return NULL;
	}

	b_queue_insert_before(&q->l_queue, &entry->e_entry, &before->e_entry);
	q->l_len++;
	return entry;
}

struct b_list_entry *b_list_insert_after(
	struct b_list *q, void *ptr, struct b_list_entry *after)
{
	struct b_list_entry *entry = make_entry(ptr);
	if (!entry) {
		return NULL;
	}

	b_queue_insert_after(&q->l_queue, &entry->e_entry, &after->e_entry);
	q->l_len++;
	return entry;
}

struct b_list_entry *b_list_push_front(struct b_list *q, void *ptr)
{
	struct b_list_entry *entry = make_entry(ptr);
	if (!entry) {
		return NULL;
	}

	b_queue_push_front(&q->l_queue, &entry->e_entry);
	q->l_len++;
	return entry;
}

struct b_list_entry *b_list_push_back(struct b_list *q, void *ptr)
{
	struct b_list_entry *entry = make_entry(ptr);
	if (!entry) {
		return NULL;
	}

	b_queue_push_back(&q->l_queue, &entry->e_entry);
	q->l_len++;
	return entry;
}

void *b_list_pop_front(struct b_list *q)
{
	struct b_queue_entry *entry = b_queue_pop_front(&q->l_queue);
	if (!entry) {
		return NULL;
	}

	struct b_list_entry *list_entry
		= b_unbox(struct b_list_entry, entry, e_entry);

	void *item = list_entry->e_data;
	free(list_entry);

	q->l_len--;

	return item;
}

void *b_list_pop_back(struct b_list *q)
{
	struct b_queue_entry *entry = b_queue_pop_back(&q->l_queue);
	if (!entry) {
		return NULL;
	}

	struct b_list_entry *list_entry
		= b_unbox(struct b_list_entry, entry, e_entry);

	void *item = list_entry->e_data;
	free(list_entry);

	q->l_len--;

	return item;
}

static struct b_list_entry *find_item(struct b_list *list, void *item)
{
	struct b_queue_iterator it;
	b_queue_foreach (&it, &list->l_queue) {
		struct b_list_entry *entry
			= b_unbox(struct b_list_entry, it.entry, e_entry);

		if (entry->e_data == item) {
			return entry;
		}
	}

	return NULL;
}

b_status b_list_delete_item(struct b_list *q, void *ptr)
{
	struct b_list_entry *entry = find_item(q, ptr);
	if (!entry) {
		return B_ERR_NO_ENTRY;
	}

	b_queue_delete(&q->l_queue, &entry->e_entry);
	q->l_len--;

	free(entry);

	return B_SUCCESS;
}

b_status b_list_delete_entry(struct b_list *q, struct b_list_entry *entry)
{
	b_queue_delete(&q->l_queue, &entry->e_entry);
	q->l_len--;

	free(entry);

	return B_SUCCESS;
}

void b_list_delete_all(struct b_list *q)
{
	struct b_queue_iterator it;
	b_queue_iterator_begin(&q->l_queue, &it);

	while (b_queue_iterator_is_valid(&it)) {
		struct b_list_entry *entry
			= b_unbox(struct b_list_entry, it.entry, e_entry);
		b_queue_iterator_erase(&it);

		free(entry);
	}

	q->l_len = 0;
}

int b_list_iterator_begin(const struct b_list *q, struct b_list_iterator *it)
{
	b_queue_iterator_begin(&q->l_queue, &it->_base);
	it->_q = q;
	it->i = 0;
	it->entry = b_unbox(struct b_list_entry, it->_base.entry, e_entry);
	if (it->entry) {
		it->item = it->entry->e_data;
	}

	return 0;
}

bool b_list_iterator_next(struct b_list_iterator *it)
{
	bool ok = b_queue_iterator_next(&it->_base);
	if (!ok) {
		it->entry = NULL;
		it->item = NULL;
		return false;
	}

	it->i++;
	it->entry = b_unbox(struct b_list_entry, it->_base.entry, e_entry);
	if (it->entry) {
		it->item = it->entry->e_data;
	}

	return it->entry != NULL;
}

b_status b_list_iterator_erase(struct b_list_iterator *it)
{
	if (!it->entry) {
		return B_ERR_OUT_OF_BOUNDS;
	}

	b_queue_iterator_erase(&it->_base);
	free(it->entry);

	it->entry = b_unbox(struct b_list_entry, it->_base.entry, e_entry);
	if (it->entry) {
		it->item = it->entry->e_data;
	}

	return B_SUCCESS;
}

bool b_list_iterator_is_valid(const struct b_list_iterator *it)
{
	return it->entry != NULL;
}

void *b_list_entry_value(const struct b_list_entry *entry)
{
	return entry ? entry->e_data : NULL;
}

static void list_release(struct b_dsref *obj)
{
	struct b_list *list = B_LIST(obj);
	b_list_delete_all(list);
}