#include <blue/core/iterator.h>
#include <blue/core/stream.h>
#include <blue/ds/array.h>
#include <blue/ds/string.h>
#include <stdlib.h>
#include <string.h>

/*** PRIVATE DATA *************************************************************/

struct b_array_p {
	/* number of items in array */
	size_t ar_len;
	/* maximum number of items that can currently be stored in array */
	size_t ar_cap;
	b_object **ar_data;
};

struct b_array_iterator_p {
	b_array *_a;
	struct b_array_p *_a_p;

	/** The index of the current value */
	size_t i;
	/** The current value */
	b_object *value;
};

/*** PRIVATE FUNCTIONS ********************************************************/

static b_status resize_array(struct b_array_p *array, size_t new_capacity)
{
	if (array->ar_cap < new_capacity) {
		void *new_data = realloc(
			array->ar_data, new_capacity * sizeof(struct b_dsref *));
		if (!new_data) {
			return B_ERR_NO_MEMORY;
		}

		array->ar_data = new_data;
	} else {
		for (size_t i = new_capacity; i < array->ar_len; i++) {
			b_object_unref(array->ar_data[i]);
		}

		void *new_data = realloc(
			array->ar_data, new_capacity * sizeof(struct b_dsref *));
		if (!new_data) {
			return B_ERR_NO_MEMORY;
		}

		array->ar_data = new_data;
	}

	array->ar_cap = new_capacity;
	if (array->ar_len > new_capacity) {
		array->ar_len = new_capacity;
	}

	return B_SUCCESS;
}

static b_status array_insert(struct b_array_p *array, b_object *value, size_t at)
{
	if (at == B_NPOS) {
		at = array->ar_len;
	}

	if (at > array->ar_len) {
		return B_ERR_OUT_OF_BOUNDS;
	}

	b_status status = B_SUCCESS;

	if (array->ar_len + 1 > array->ar_cap) {
		status = resize_array(array, array->ar_cap + 8);

		if (status != B_SUCCESS) {
			return status;
		}
	}

	b_object **src = array->ar_data + at;
	b_object **dest = src + 1;
	size_t move_len = (array->ar_len - at) * sizeof(struct b_dsref *);

	memmove(dest, src, move_len);

	array->ar_data[at] = b_object_ref(value);
	array->ar_len++;

	return B_SUCCESS;
}

static b_status array_remove(struct b_array_p *array, size_t at)
{
	if (at >= array->ar_len) {
		return B_ERR_OUT_OF_BOUNDS;
	}

	b_object **src = array->ar_data + at;
	b_object **dest = src + 1;
	size_t move_len = array->ar_len * sizeof(struct b_dsref *);

	b_object_unref(array->ar_data[at]);

	memmove(dest, src, move_len);

	array->ar_len--;

	return B_SUCCESS;
}

static b_status array_remove_front(struct b_array_p *array)
{
	return array_remove(array, 0);
}

static b_status array_remove_back(struct b_array_p *array)
{
	return array_remove(array, array->ar_len - 1);
}

static b_object *array_pop(struct b_array_p *array, size_t at)
{
	if (at >= array->ar_len) {
		return NULL;
	}

	b_object **src = array->ar_data + at;
	b_object **dest = src + 1;
	size_t move_len = array->ar_len * sizeof(struct b_dsref *);

	b_object *out = array->ar_data[at];

	memmove(dest, src, move_len);

	array->ar_len--;

	return out;
}

static b_object *array_pop_front(struct b_array_p *array)
{
	return array_pop(array, 0);
}

static b_object *array_pop_back(struct b_array_p *array)
{
	return array_pop(array, array->ar_len - 1);
}

static b_object *array_at(const struct b_array_p *array, size_t at)
{
	if (at >= array->ar_len) {
		return NULL;
	}

	return array->ar_data[at];
}

static b_object *array_get(struct b_array_p *array, size_t at)
{
	if (at >= array->ar_len) {
		return NULL;
	}

	return b_object_ref(array->ar_data[at]);
}

static size_t array_size(const struct b_array_p *array)
{
	return array->ar_len;
}

static size_t array_capacity(const struct b_array_p *array)
{
	return array->ar_cap;
}

static void array_clear(struct b_array_p *array)
{
	if (!array->ar_len) {
		return;
	}

	for (size_t i = 0; i < array->ar_len; i++) {
		b_object_unref(array->ar_data[i]);
	}

	memset(array->ar_data, 0x0, array->ar_cap * sizeof(b_object *));
	array->ar_len = 0;
}

/*** PUBLIC FUNCTIONS *********************************************************/

b_array *b_array_create_with_values(b_object *const *values, size_t nr_values)
{
	b_array *array = b_array_create();
	if (!array) {
		return NULL;
	}

	struct b_array_p *p = b_object_get_private(array, B_TYPE_ARRAY);

	size_t real_nr_values = 0;
	for (size_t i = 0; i < nr_values; i++) {
		if (values[i]) {
			real_nr_values++;
		}
	}

	p->ar_len = real_nr_values;
	p->ar_cap = real_nr_values;
	p->ar_data = calloc(real_nr_values, sizeof(struct b_dsref *));
	if (!p->ar_data) {
		b_array_unref(array);
		return NULL;
	}

	size_t index = 0;
	for (size_t i = 0; i < nr_values; i++) {
		p->ar_data[index++] = b_object_ref(values[i]);
	}

	return array;
}

b_status b_array_insert(b_array *array, b_object *value, size_t at)
{
	B_CLASS_DISPATCH_STATIC(B_TYPE_ARRAY, array_insert, array, value, at);
}

b_status b_array_remove(b_array *array, size_t at)
{
	B_CLASS_DISPATCH_STATIC(B_TYPE_ARRAY, array_remove, array, at);
}

b_status b_array_remove_front(b_array *array)
{
	B_CLASS_DISPATCH_STATIC_0(B_TYPE_ARRAY, array_remove_front, array);
}

b_status b_array_remove_back(b_array *array)
{
	B_CLASS_DISPATCH_STATIC_0(B_TYPE_ARRAY, array_remove_back, array);
}

b_object *b_array_pop(b_array *array, size_t at)
{
	B_CLASS_DISPATCH_STATIC(B_TYPE_ARRAY, array_pop, array, at);
}

b_object *b_array_pop_front(b_array *array)
{
	B_CLASS_DISPATCH_STATIC_0(B_TYPE_ARRAY, array_pop_front, array);
}

b_object *b_array_pop_back(b_array *array)
{
	B_CLASS_DISPATCH_STATIC_0(B_TYPE_ARRAY, array_pop_back, array);
}

b_object *b_array_at(const b_array *array, size_t at)
{
	B_CLASS_DISPATCH_STATIC(B_TYPE_ARRAY, array_at, array, at);
}

b_object *b_array_get(b_array *array, size_t at)
{
	B_CLASS_DISPATCH_STATIC(B_TYPE_ARRAY, array_get, array, at);
}

size_t b_array_size(const b_array *array)
{
	B_CLASS_DISPATCH_STATIC_0(B_TYPE_ARRAY, array_size, array);
}

size_t b_array_capacity(const b_array *array)
{
	B_CLASS_DISPATCH_STATIC_0(B_TYPE_ARRAY, array_capacity, array);
}

void b_array_clear(b_array *array)
{
	B_CLASS_DISPATCH_STATIC_0(B_TYPE_ARRAY, array_clear, array);
}

/*** PUBLIC ALIAS FUNCTIONS ***************************************************/

b_status b_array_append(b_array *array, b_object *value)
{
	return b_array_insert(array, value, B_NPOS);
}

b_status b_array_prepend(b_array *array, b_object *value)
{
	return b_array_insert(array, value, 0);
}

/*** VIRTUAL FUNCTIONS ********************************************************/

static void array_init(b_object *obj, void *priv)
{
	struct b_array_p *array = priv;
}

static void array_fini(b_object *obj, void *priv)
{
	struct b_array_p *array = priv;

	if (array->ar_data) {
		for (size_t i = 0; i < array->ar_len; i++) {
			b_object_unref(array->ar_data[i]);
		}

		free(array->ar_data);
		array->ar_data = NULL;
	}
}

static void array_to_string(const b_object *obj, b_stream *out)
{
	struct b_array_p *array = b_object_get_private(obj, B_TYPE_ARRAY);

	if (!array->ar_len) {
		b_stream_write_string(out, "[]", NULL);
		return;
	}

	b_stream_write_string(out, "[\n", NULL);

	b_stream_push_indent(out, 1);
	size_t len = array_size(array);

	for (size_t i = 0; i < array->ar_len; i++) {
		b_object *value = array->ar_data[i];
		bool is_string = b_object_is_type(value, B_TYPE_STRING);

		if (is_string) {
			b_stream_write_char(out, '"');
		}

		b_object_to_string(value, out);

		if (is_string) {
			b_stream_write_char(out, '"');
		}

		if (i < len - 1) {
			b_stream_write_string(out, ",", NULL);
		}

		b_stream_write_char(out, '\n');
	}

	b_stream_pop_indent(out);
	b_stream_write_char(out, ']');
}

/*** ITERATOR FUNCTIONS *******************************************************/

static b_iterator *iterable_begin(b_object *obj)
{
	b_array_iterator *it_obj = b_object_create(B_TYPE_ARRAY_ITERATOR);
	struct b_array_iterator_p *it
		= b_object_get_private(it_obj, B_TYPE_ARRAY_ITERATOR);
	it->_a = obj;
	it->_a_p = b_object_get_private(obj, B_TYPE_ARRAY);
	it->i = 0;

	if (it->_a_p->ar_len > 0) {
		it->value = it->_a_p->ar_data[0];
	} else {
		it->value = NULL;
	}

	return it_obj;
}

static const b_iterator *iterable_cbegin(const b_object *obj)
{
	b_array_iterator *it_obj = b_object_create(B_TYPE_ARRAY_ITERATOR);
	struct b_array_iterator_p *it
		= b_object_get_private(it_obj, B_TYPE_ARRAY_ITERATOR);
	it->_a = (b_array *)obj;
	it->_a_p = b_object_get_private(obj, B_TYPE_ARRAY);
	it->i = 0;

	if (it->_a_p->ar_len > 0) {
		it->value = it->_a_p->ar_data[0];
	} else {
		it->value = NULL;
	}

	return it_obj;
}

static enum b_status iterator_move_next(const b_iterator *obj)
{
	struct b_array_iterator_p *it
		= b_object_get_private(obj, B_TYPE_ARRAY_ITERATOR);
	struct b_array_p *array = it->_a_p;

	if (it->value == NULL || it->i >= array->ar_len) {
		return false;
	}

	it->i++;

	if (it->i >= array->ar_len) {
		it->value = NULL;
	} else {
		it->value = array->ar_data[it->i];
	}

	return (it->value != NULL) ? B_SUCCESS : B_ERR_NO_DATA;
}

static enum b_status iterator_erase(b_iterator *obj)
{
	struct b_array_iterator_p *it
		= b_object_get_private(obj, B_TYPE_ARRAY_ITERATOR);
	struct b_array_p *array = it->_a_p;

	if (it->i >= array->ar_len) {
		return B_ERR_OUT_OF_BOUNDS;
	}

	if (array->ar_data[it->i] != it->value) {
		return B_ERR_BAD_STATE;
	}

	array_remove(array, it->i);

	if (it->i < array->ar_len) {
		it->value = array->ar_data[it->i];
	} else {
		it->value = NULL;
	}

	return B_SUCCESS;
}

static b_iterator_value iterator_get_value(b_iterator *obj)
{
	struct b_array_iterator_p *it
		= b_object_get_private(obj, B_TYPE_ARRAY_ITERATOR);

	return B_ITERATOR_VALUE_PTR(it->value);
}

static const b_iterator_value iterator_get_cvalue(const b_iterator *obj)
{
	struct b_array_iterator_p *it
		= b_object_get_private(obj, B_TYPE_ARRAY_ITERATOR);

	return B_ITERATOR_VALUE_CPTR(it->value);
}

static enum b_status iterator_is_valid(const b_iterator *obj)
{
	struct b_array_iterator_p *it
		= b_object_get_private(obj, B_TYPE_ARRAY_ITERATOR);
	struct b_array_p *array = it->_a_p;

	if (it->i >= array->ar_len) {
		return false;
	}

	if (array->ar_data[it->i] != it->value) {
		return false;
	}

	return (it->value != NULL) ? B_SUCCESS : B_ERR_NO_DATA;
}

/*** CLASS DEFINITION *********************************************************/

// ---- b_array DEFINITION
B_TYPE_CLASS_DEFINITION_BEGIN(b_array)
	B_TYPE_CLASS_INTERFACE_BEGIN(b_object, B_TYPE_OBJECT)
		B_INTERFACE_ENTRY(to_string) = array_to_string;
	B_TYPE_CLASS_INTERFACE_END(b_object, B_TYPE_OBJECT)

	B_TYPE_CLASS_INTERFACE_BEGIN(b_iterable, B_TYPE_ITERABLE)
		B_INTERFACE_ENTRY(it_begin) = iterable_begin;
		B_INTERFACE_ENTRY(it_cbegin) = iterable_cbegin;
	B_TYPE_CLASS_INTERFACE_END(b_iterable, B_TYPE_ITERABLE)
B_TYPE_CLASS_DEFINITION_END(b_array)

B_TYPE_DEFINITION_BEGIN(b_array)
	B_TYPE_ID(0xe3c46da1, 0x5f37, 0x4e44, 0xb53b, 0xff5a6200191b);
	B_TYPE_CLASS(b_array_class);
	B_TYPE_IMPLEMENTS(B_TYPE_ITERABLE);
	B_TYPE_INSTANCE_PRIVATE(struct b_array_p);
	B_TYPE_INSTANCE_INIT(array_init);
	B_TYPE_INSTANCE_FINI(array_fini);
B_TYPE_DEFINITION_END(b_array)

// ---- b_array_iterator DEFINITION
B_TYPE_CLASS_DEFINITION_BEGIN(b_array_iterator)
	B_TYPE_CLASS_INTERFACE_BEGIN(b_object, B_TYPE_OBJECT)
		B_INTERFACE_ENTRY(to_string) = NULL;
	B_TYPE_CLASS_INTERFACE_END(b_object, B_TYPE_OBJECT)

	B_TYPE_CLASS_INTERFACE_BEGIN(b_iterator, B_TYPE_ITERATOR)
		B_INTERFACE_ENTRY(it_move_next) = iterator_move_next;
		B_INTERFACE_ENTRY(it_erase) = iterator_erase;
		B_INTERFACE_ENTRY(it_get_value) = iterator_get_value;
		B_INTERFACE_ENTRY(it_get_cvalue) = iterator_get_cvalue;
	B_TYPE_CLASS_INTERFACE_END(b_iterator, B_TYPE_ITERATOR)
B_TYPE_CLASS_DEFINITION_END(b_array_iterator)

B_TYPE_DEFINITION_BEGIN(b_array_iterator)
	B_TYPE_ID(0xe5e9e8b8, 0x14cb, 0x4192, 0x8138, 0xf45238a2ae73);
	B_TYPE_EXTENDS(B_TYPE_ITERATOR);
	B_TYPE_CLASS(b_array_iterator_class);
	B_TYPE_INSTANCE_PRIVATE(struct b_array_iterator_p);
B_TYPE_DEFINITION_END(b_array_iterator)