#include <blue/core/rope.h>
#include <blue/object/string.h>
#include <mie/name.h>
#include <stdlib.h>
#include <string.h>

B_BTREE_DEFINE_SIMPLE_INSERT(struct mie_name_map_entry, e_node, e_hash, put_entry)
B_BTREE_DEFINE_SIMPLE_GET(
	struct mie_name_map_entry, uint64_t, e_node, e_hash, get_entry)

static struct mie_name_bucket *create_bucket(void)
{
	struct mie_name_bucket *out = malloc(sizeof *out);

	if (!out) {
		return NULL;
	}

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

	out->b_base.e_type = MIE_NAME_MAP_E_BUCKET;

	return out;
}

static void destroy_bucket(struct mie_name_bucket *bucket)
{
	b_queue_iterator it;
	b_queue_iterator_begin(&bucket->b_names, &it);

	while (b_queue_iterator_is_valid(&it)) {
		b_queue_iterator_erase(&it);
	}

	free(bucket);
}

struct mie_name_map *mie_name_map_create(void)
{
	struct mie_name_map *out = malloc(sizeof *out);
	if (!out) {
		return NULL;
	}

	memset(out, 0x0, sizeof *out);
	return out;
}

void mie_name_map_destroy(struct mie_name_map *map)
{
	b_btree_iterator it;
	b_btree_iterator_begin(&map->m_entries, &it);

	while (b_btree_iterator_is_valid(&it)) {
		struct mie_name_map_entry *entry
			= b_unbox(struct mie_name_map_entry, it.node, e_node);
		b_btree_iterator_erase(&it);

		if (entry->e_type == MIE_NAME_MAP_E_BUCKET) {
			struct mie_name_bucket *bucket
				= (struct mie_name_bucket *)entry;
			destroy_bucket(bucket);
		}
	}

	free(map);
}

static b_status put_name_in_bucket(
	struct mie_name_bucket *bucket, struct mie_name *name)
{
	b_queue_iterator it;
	b_queue_foreach (&it, &bucket->b_names) {
		struct mie_name *cur = (struct mie_name *)b_unbox(
			struct mie_name_map_entry, it.entry, e_entry);

		if (!strcmp(cur->n_str, name->n_str)) {
			return B_ERR_NAME_EXISTS;
		}
	}

	b_queue_push_back(&bucket->b_names, &name->n_base.e_entry);

	return B_SUCCESS;
}

static b_status put_name(struct mie_name_map *map, struct mie_name *name)
{
	struct mie_name_map_entry *entry
		= get_entry(&map->m_entries, name->n_base.e_hash);

	if (!entry) {
		put_entry(&map->m_entries, &name->n_base);
		return B_SUCCESS;
	}

	if (entry->e_type == MIE_NAME_MAP_E_BUCKET) {
		struct mie_name_bucket *bucket = (struct mie_name_bucket *)entry;
		return put_name_in_bucket(bucket, name);
	}

	struct mie_name *existing_name = (struct mie_name *)entry;

	if (!strcmp(existing_name->n_str, name->n_str)) {
		return B_ERR_NAME_EXISTS;
	}

	struct mie_name_bucket *bucket = create_bucket();
	if (!bucket) {
		return B_ERR_NO_MEMORY;
	}

	b_btree_delete(&map->m_entries, &entry->e_node);
	entry->e_entry = B_QUEUE_ENTRY_INIT;

	bucket->b_base.e_hash = name->n_base.e_hash;
	b_queue_push_back(&bucket->b_names, &existing_name->n_base.e_entry);
	b_queue_push_back(&bucket->b_names, &name->n_base.e_entry);

	put_entry(&map->m_entries, &bucket->b_base);

	return B_SUCCESS;
}

struct mie_name *mie_name_map_put(
	struct mie_name_map *map, struct mie_name *entry, const char *hint,
	enum mie_name_map_flags flags)
{
	memset(entry, 0x0, sizeof *entry);
	entry->n_base.e_type = MIE_NAME_MAP_E_NAME;

	b_rope base = {};

	if (hint) {
		b_rope_init_cstr_borrowed(&base, hint);
	}

	char str[256];

	if (hint) {
		/* first try just the hint on its own */
		b_rope_to_cstr(&base, str, sizeof str);
		entry->n_str = str;
		entry->n_base.e_hash = base.r_v.v_cstr.hash;
		b_status status = put_name(map, entry);

		if (B_OK(status)) {
			entry->n_str = b_strdup(str);
			return entry;
		}
	}

	if (flags & MIE_NAME_MAP_STRICT) {
		/* the caller insists that `hint` be used as the name.
		 * such a name already exists, so we can't help them */
		return NULL;
	}

	/* that name already exists, use a suffix to make the name unique.
	 * alternately, no hint was specified, so it's up to us to generate the name */
	b_rope dot = B_ROPE_CHAR('.');
	b_rope suffix = B_ROPE_UINT(0);
	b_rope unique_name;

	if (hint) {
		const b_rope *parts[] = {&base, &dot, &suffix};
		b_rope_join(&unique_name, parts, sizeof parts / sizeof parts[0]);
	} else {
		b_rope_concat(&unique_name, &base, &suffix);
	}

	size_t i = 0;
	if (!hint || hint[0] == '\0') {
		i = map->m_next_id++;
	}

	for (;; i++) {
		suffix.r_v.v_uint = i;

		b_rope_to_cstr(&unique_name, str, sizeof str);

		entry->n_str = str;
		entry->n_base.e_hash = b_hash_string(str);
		b_status status = put_name(map, entry);

		if (B_OK(status)) {
			entry->n_str = b_strdup(str);
			b_rope_destroy(&unique_name);
			return entry;
		}
	}

	b_rope_destroy(&unique_name);

	return NULL;
}