/*
Copyright (c) 2019-2023 Péter Magyar

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/

#include "terrain_world.h"

#include "core/object/message_queue.h"
#include "terrain_chunk.h"
#include "terrain_structure.h"

#include "../defines.h"

#include "modules/modules_enabled.gen.h"

#ifdef MODULE_PROPS_ENABLED
#include "../../props/props/prop_data.h"
#include "../../props/props/prop_data_entry.h"
#include "../../props/props/prop_data_light.h"
#include "../../props/props/prop_data_prop.h"
#include "../../props/props/prop_data_scene.h"
#endif

#ifdef MODULE_MESH_DATA_RESOURCE_ENABLED
#include "../../mesh_data_resource/props/prop_data_mesh_data.h"
#endif

#if TOOLS_ENABLED
#include "editor/plugins/spatial_editor_plugin.h"
#include "scene/3d/camera.h"
#endif

const String TerrainWorld::BINDING_STRING_CHANNEL_TYPE_INFO = "Type,Isolevel,Liquid,Liquid Level";

bool TerrainWorld::get_active() const {
	return _active;
}
void TerrainWorld::set_active(const bool value) {
	_active = value;

	notification(NOTIFICATION_ACTIVE_STATE_CHANGED);
}

bool TerrainWorld::get_editable() const {
	return _editable;
}
void TerrainWorld::set_editable(const bool value) {
	_editable = value;
}

int TerrainWorld::get_chunk_size_x() const {
	return _chunk_size_x;
}
void TerrainWorld::set_chunk_size_x(const int value) {
	_chunk_size_x = value;
}

int TerrainWorld::get_chunk_size_z() const {
	return _chunk_size_z;
}
void TerrainWorld::set_chunk_size_z(const int value) {
	_chunk_size_z = value;
}

int TerrainWorld::get_data_margin_start() const {
	return _data_margin_start;
}
void TerrainWorld::set_data_margin_start(const int value) {
	_data_margin_start = value;
}

int TerrainWorld::get_data_margin_end() const {
	return _data_margin_end;
}
void TerrainWorld::set_data_margin_end(const int value) {
	_data_margin_end = value;
}

int TerrainWorld::get_current_seed() const {
	return _current_seed;
}
void TerrainWorld::set_current_seed(const int value) {
	_current_seed = value;
}

_FORCE_INLINE_ float TerrainWorld::get_world_height() const {
	return _world_height;
}
void TerrainWorld::set_world_height(const float value) {
	_world_height = value;
}

int TerrainWorld::get_max_concurrent_generations() {
	return _max_concurrent_generations;
}
void TerrainWorld::set_max_concurrent_generations(const int value) {
	_max_concurrent_generations = value;
}

Ref<TerrainLibrary> TerrainWorld::get_library() {
	return _library;
}
void TerrainWorld::set_library(const Ref<TerrainLibrary> &library) {
	_library = library;

	for (int i = 0; i < chunk_get_count(); ++i) {
		Ref<TerrainChunk> c = chunk_get_index(i);

		if (!c.is_valid())
			continue;

		c->set_library(_library);
	}
}

Ref<TerrainLevelGenerator> TerrainWorld::get_level_generator() const {
	return _level_generator;
}
void TerrainWorld::set_level_generator(const Ref<TerrainLevelGenerator> &level_generator) {
	_level_generator = level_generator;
}

float TerrainWorld::get_voxel_scale() const {
	return _voxel_scale;
}
void TerrainWorld::set_voxel_scale(const float value) {
	_voxel_scale = value;

	for (int i = 0; i < chunk_get_count(); ++i) {
		Ref<TerrainChunk> c = chunk_get_index(i);

		if (!c.is_valid())
			continue;

		c->set_voxel_scale(_voxel_scale);
	}
}

int TerrainWorld::get_chunk_spawn_range() const {
	return _chunk_spawn_range;
}
void TerrainWorld::set_chunk_spawn_range(const int value) {
	_chunk_spawn_range = value;
}

NodePath TerrainWorld::get_player_path() const {
	return _player_path;
}

void TerrainWorld::set_player_path(const NodePath &player_path) {
	_player_path = player_path;
}

Spatial *TerrainWorld::get_player() const {
	return _player;
}
void TerrainWorld::set_player(Spatial *player) {
	_player = player;
}
void TerrainWorld::set_player_bind(Node *player) {
	set_player(Object::cast_to<Spatial>(player));
}

Ref<TerrainWorldArea> TerrainWorld::world_area_get(const int index) const {
	ERR_FAIL_INDEX_V(index, _world_areas.size(), Ref<TerrainWorldArea>());

	return _world_areas.get(index);
}
void TerrainWorld::world_area_add(const Ref<TerrainWorldArea> &area) {
	_world_areas.push_back(area);
}
void TerrainWorld::world_area_remove(const int index) {
	ERR_FAIL_INDEX(index, _world_areas.size());

	_world_areas.remove(index);
}
void TerrainWorld::world_areas_clear() {
	_world_areas.clear();
}
int TerrainWorld::world_area_get_count() const {
	return _world_areas.size();
}

//Terra Structures

Ref<TerrainStructure> TerrainWorld::voxel_structure_get(const int index) const {
	ERR_FAIL_INDEX_V(index, _voxel_structures.size(), Ref<TerrainStructure>());

	return _voxel_structures.get(index);
}
void TerrainWorld::voxel_structure_add(const Ref<TerrainStructure> &structure) {
	_voxel_structures.push_back(structure);
}
void TerrainWorld::voxel_structure_remove(const Ref<TerrainStructure> &structure) {
	if (!structure.is_valid())
		return;

	int index = _voxel_structures.find(structure);

	if (index != -1)
		_voxel_structures.remove(index);
}
void TerrainWorld::voxel_structure_remove_index(const int index) {
	ERR_FAIL_INDEX(index, _voxel_structures.size());

	_voxel_structures.remove(index);
}
void TerrainWorld::voxel_structures_clear() {
	_voxel_structures.clear();
}
int TerrainWorld::voxel_structure_get_count() const {
	return _voxel_structures.size();
}
void TerrainWorld::voxel_structure_add_at_position(Ref<TerrainStructure> structure, const Vector3 &world_position) {
	ERR_FAIL_COND(!structure.is_valid());

	structure->set_position_x(static_cast<int>(world_position.x / _voxel_scale));
	structure->set_position_y(static_cast<int>(world_position.y / _voxel_scale));
	structure->set_position_z(static_cast<int>(world_position.z / _voxel_scale));

	voxel_structure_add(structure);
}

Vector<Variant> TerrainWorld::voxel_structures_get() {
	VARIANT_ARRAY_GET(_voxel_structures);
}
void TerrainWorld::voxel_structures_set(const Vector<Variant> &structures) {
	voxel_structures_clear();

	for (int i = 0; i < structures.size(); ++i) {
		Ref<TerrainLight> structure = Ref<TerrainLight>(structures[i]);

		voxel_structure_add(structure);
	}
}

void TerrainWorld::chunk_add(Ref<TerrainChunk> chunk, const int x, const int z) {
	ERR_FAIL_COND(!chunk.is_valid());
	ERR_FAIL_COND_MSG(chunk->get_voxel_world() != NULL && chunk->get_voxel_world() != this, "Chunk is already owned by an another world!");

	IntPos pos(x, z);

	//ERR_FAIL_COND(_chunks.has(pos));

	chunk->set_voxel_world(this);
	chunk->set_position(x, z);
	chunk->world_transform_changed();

	if (!_chunks.has(pos))
		_chunks.set(pos, chunk);

	if (_chunks_vector.find(chunk) == -1)
		_chunks_vector.push_back(chunk);

	if (is_inside_tree())
		chunk->enter_tree();

	if (has_method("_chunk_added")) {
		call("_chunk_added", chunk);
	}

	emit_signal("chunk_added", chunk);
}
bool TerrainWorld::chunk_has(const int x, const int z) const {
	return _chunks.has(IntPos(x, z));
}
Ref<TerrainChunk> TerrainWorld::chunk_get(const int x, const int z) {
	IntPos pos(x, z);

	if (_chunks.has(pos))
		return _chunks.get(pos);

	return Ref<TerrainChunk>();
}
Ref<TerrainChunk> TerrainWorld::chunk_remove(const int x, const int z) {
	IntPos pos(x, z);

	if (!_chunks.has(pos)) {
		return NULL;
	}

	Ref<TerrainChunk> chunk = _chunks.get(pos);

	chunk->exit_tree();

	for (int i = 0; i < _chunks_vector.size(); ++i) {
		if (_chunks_vector.get(i) == chunk) {
			_chunks_vector.remove(i);
			break;
		}
	}

	_generation_queue.erase(chunk);

	if (chunk->get_is_generating()) {
		chunk->cancel_build();
	}

	//never remove from this here
	//_generating.erase(chunk);

	_chunks.erase(pos);

	emit_signal("chunk_removed", chunk);

	return chunk;
}
Ref<TerrainChunk> TerrainWorld::chunk_remove_index(const int index) {
	ERR_FAIL_INDEX_V(index, _chunks_vector.size(), NULL);

	Ref<TerrainChunk> chunk = _chunks_vector.get(index);
	chunk->exit_tree();

	_chunks_vector.remove(index);
	_chunks.erase(IntPos(chunk->get_position_x(), chunk->get_position_z()));
	_generation_queue.erase(chunk);

	if (chunk->get_is_generating()) {
		chunk->cancel_build();
	}

	//never remove from this here
	//_generating.erase(chunk);

	emit_signal("chunk_removed", chunk);

	return chunk;
}

Ref<TerrainChunk> TerrainWorld::chunk_get_index(const int index) {
	ERR_FAIL_INDEX_V(index, _chunks_vector.size(), NULL);

	return _chunks_vector.get(index);
}
int TerrainWorld::chunk_get_count() const {
	return _chunks_vector.size();
}

void TerrainWorld::chunks_clear() {
	for (int i = 0; i < _chunks_vector.size(); ++i) {
		Ref<TerrainChunk> chunk = _chunks_vector.get(i);

		chunk->exit_tree();

		emit_signal("chunk_removed", chunk);
	}

	_chunks_vector.clear();
	_chunks.clear();
	_generation_queue.clear();

	for (int i = 0; i < _generating.size(); ++i) {
		Ref<TerrainChunk> chunk = _generating[i];

		if (chunk->get_is_generating()) {
			chunk->cancel_build();
		}
	}

	//never remove from this here
	//_generating.clear();
}

Ref<TerrainChunk> TerrainWorld::chunk_get_or_create(int x, int z) {
	Ref<TerrainChunk> chunk = chunk_get(x, z);

	if (!chunk.is_valid()) {
		chunk = chunk_create(x, z);
	}

	return chunk;
}

Ref<TerrainChunk> TerrainWorld::chunk_create(const int x, const int z) {
	Ref<TerrainChunk> c;
	c = call("_create_chunk", x, z, Ref<TerrainChunk>());

	generation_queue_add_to(c);

	return c;
}

void TerrainWorld::chunk_setup(Ref<TerrainChunk> chunk) {
	ERR_FAIL_COND(!chunk.is_valid());

	call("_create_chunk", chunk->get_position_x(), chunk->get_position_z(), chunk);
}

Ref<TerrainChunk> TerrainWorld::_create_chunk(const int x, const int z, Ref<TerrainChunk> chunk) {
	if (!chunk.is_valid()) {
		chunk.instance();
	}

	//no meshers here

	ERR_FAIL_COND_V(!chunk.is_valid(), NULL);

	chunk->set_name("Chunk[" + String::num(x) + "," + String::num(z) + "]");

	chunk->set_voxel_world(this);

	chunk->set_position(x, z);
	chunk->set_world_height(_world_height);
	chunk->set_library(_library);
	chunk->set_voxel_scale(_voxel_scale);
	chunk->set_size(_chunk_size_x, _chunk_size_z, _data_margin_start, _data_margin_end);
	//chunk->set_translation(Vector3(x * _chunk_size_x * _voxel_scale, y * _chunk_size_y * _voxel_scale, z * _chunk_size_z * _voxel_scale));

	if (!get_active()) {
		chunk->set_visible(false);
	}

	chunk_add(chunk, x, z);

	return chunk;
}

void TerrainWorld::chunk_generate(Ref<TerrainChunk> chunk) {
	ERR_FAIL_COND(!chunk.is_valid());

	if (has_method("_prepare_chunk_for_generation")) {
		call("_prepare_chunk_for_generation", chunk);
	}

	call("_generate_chunk", chunk);

	chunk->build();
}

Vector<Variant> TerrainWorld::chunks_get() {
	VARIANT_ARRAY_GET(_chunks_vector);
}

void TerrainWorld::chunks_set(const Vector<Variant> &chunks) {
	if (is_inside_tree()) {
		for (int i = 0; i < _chunks_vector.size(); ++i) {
			Ref<TerrainChunk> chunk = Ref<TerrainChunk>(_chunks_vector[i]);

			if (chunks.find(chunk) == -1) {
				chunk_remove_index(i);
				_generation_queue.erase(chunk);

				chunk->exit_tree();

				if (chunk->get_is_generating()) {
					chunk->cancel_build();
				}

				//never remove from this here
				//_generating.erase(chunk);

				--i;
			}
		}

		//add the difference
		for (int i = 0; i < chunks.size(); ++i) {
			Ref<TerrainChunk> chunk = Ref<TerrainChunk>(chunks[i]);

			if (!chunk.is_valid())
				continue;

			if (_chunks_vector.find(chunk) != -1)
				continue;

			chunk_add(chunk, chunk->get_position_x(), chunk->get_position_z());
		}
	} else {
		_chunks_vector.clear();

		for (int i = 0; i < chunks.size(); ++i) {
			Ref<TerrainChunk> chunk = Ref<TerrainChunk>(chunks[i]);

			_chunks_vector.push_back(chunk);
		}
	}
}

int TerrainWorld::_get_channel_index_info(const TerrainWorld::ChannelTypeInfo channel_type) {
	return -1;
}

void TerrainWorld::_set_voxel_with_tool(const bool mode_add, const Vector3 hit_position, const Vector3 hit_normal, const int selected_voxel, const int isolevel) {
	Vector3 pos;

	if (mode_add) {
		pos = (hit_position + (Vector3(0.1, 0.1, 0.1) * hit_normal * get_voxel_scale()));
	} else {
		pos = (hit_position + (Vector3(0.1, 0.1, 0.1) * -hit_normal * get_voxel_scale()));
	}

	int channel_type = get_channel_index_info(TerrainWorld::CHANNEL_TYPE_INFO_TYPE);
	int channel_isolevel = get_channel_index_info(TerrainWorld::CHANNEL_TYPE_INFO_ISOLEVEL);

	if (channel_isolevel == -1) {
		set_voxel_at_world_position(pos, selected_voxel, channel_type);
	} else {
		set_voxel_at_world_position(pos, selected_voxel, channel_type, false);
		set_voxel_at_world_position(pos, isolevel, channel_isolevel);
	}
}

bool TerrainWorld::can_chunk_do_build_step() {
	if (_max_frame_chunk_build_steps == 0) {
		return true;
	}

	return _num_frame_chunk_build_steps++ < _max_frame_chunk_build_steps;
}

bool TerrainWorld::is_position_walkable(const Vector3 &p_pos) {
	int x = static_cast<int>(Math::floor(p_pos.x / (_chunk_size_x * _voxel_scale)));
	int z = static_cast<int>(Math::floor(p_pos.z / (_chunk_size_z * _voxel_scale)));

	Ref<TerrainChunk> c = chunk_get(x, z);

	if (!c.is_valid())
		return false;

	return !c->get_is_generating();
}

void TerrainWorld::on_chunk_mesh_generation_finished(Ref<TerrainChunk> p_chunk) {
	call_deferred("emit_signal", "chunk_mesh_generation_finished", p_chunk);
}

void TerrainWorld::generation_queue_add_to(const Ref<TerrainChunk> &chunk) {
	ERR_FAIL_COND(!chunk.is_valid());

	set_process_internal(true);

	_generation_queue.push_back(chunk);
}
Ref<TerrainChunk> TerrainWorld::generation_queue_get_index(int index) {
	ERR_FAIL_INDEX_V(index, _generation_queue.size(), NULL);

	return _generation_queue.get(index);
}
void TerrainWorld::generation_queue_remove_index(int index) {
	ERR_FAIL_INDEX(index, _generation_queue.size());

	_generation_queue.remove(index);
}
int TerrainWorld::generation_queue_get_size() const {
	return _generation_queue.size();
}

void TerrainWorld::generation_add_to(const Ref<TerrainChunk> &chunk) {
	ERR_FAIL_COND(!chunk.is_valid());

	_generating.push_back(chunk);
}
Ref<TerrainChunk> TerrainWorld::generation_get_index(const int index) {
	ERR_FAIL_INDEX_V(index, _generating.size(), NULL);

	return _generating.get(index);
}
void TerrainWorld::generation_remove_index(const int index) {
	ERR_FAIL_INDEX(index, _generating.size());

	_generating.remove(index);
}
int TerrainWorld::generation_get_size() const {
	return _generating.size();
}

#ifdef MODULE_PROPS_ENABLED
void TerrainWorld::prop_add(Transform transform, const Ref<PropData> &prop, const bool apply_voxel_scale) {
	ERR_FAIL_COND(!prop.is_valid());

	if (apply_voxel_scale) {
		transform = transform.scaled(Vector3(get_voxel_scale(), get_voxel_scale(), get_voxel_scale()));
	}

	Vector3 wp;
	wp = transform.xform(wp);
	Ref<TerrainChunk> chunk = get_or_create_chunk_at_world_position(wp);

	chunk->prop_add(transform, prop);

	int count = prop->get_prop_count();
	for (int i = 0; i < count; ++i) {
		Ref<PropDataEntry> entry = prop->get_prop(i);

		if (!entry.is_valid())
			continue;

		Transform t = transform * entry->get_transform();

		wp = t.xform(Vector3());
		chunk = get_or_create_chunk_at_world_position(wp);

		Ref<PropDataProp> prop_entry_data = entry;

		if (prop_entry_data.is_valid()) {
			Ref<PropData> p = prop_entry_data->get_prop();

			if (!p.is_valid())
				continue;

			prop_add(t, p, false);

			continue;
		}

		Ref<PropDataScene> scene_data = entry;

		if (scene_data.is_valid()) {
			Ref<PackedScene> sc = scene_data->get_scene();

			if (!sc.is_valid())
				continue;

			Node *n = sc->instance();
			add_child(n);
			n->set_owner(this);

			Spatial *sp = Object::cast_to<Spatial>(n);

			if (sp) {
				sp->set_transform(t);
			}

			continue;
		}

		Ref<PropDataLight> light_data = entry;

		if (light_data.is_valid()) {
			Ref<TerrainLight> light;
			light.instance();

			light->set_world_position(wp.x / get_voxel_scale(), wp.y / get_voxel_scale(), wp.z / get_voxel_scale());
			light->set_color(light_data->get_light_color());
			light->set_size(light_data->get_light_size());

			light_add(light);

			continue;
		}

#ifdef MODULE_MESH_DATA_RESOURCE_ENABLED
		Ref<PropDataMeshData> mesh_data = entry;

		if (mesh_data.is_valid()) {
			Ref<MeshDataResource> mdr = mesh_data->get_mesh();

			if (!mdr.is_valid())
				continue;

			Transform chunk_local_tform = t;

			chunk_local_tform.origin = chunk->to_local(chunk_local_tform.origin);

			chunk->mesh_data_resource_add(chunk_local_tform, mdr, mesh_data->get_texture(), Color(1, 1, 1, 1), false);

			continue;
		}
#endif
	}
}
#endif

//Lights
void TerrainWorld::light_add(const Ref<TerrainLight> &light) {
	_lights.push_back(light);

	for (int i = 0; i < _chunks_vector.size(); ++i) {
		Ref<TerrainChunk> chunk = _chunks_vector[i];

		if (chunk.is_valid()) {
			chunk->world_light_added(light);
		}
	}
}
Ref<TerrainLight> TerrainWorld::light_get(const int index) {
	ERR_FAIL_INDEX_V(index, _lights.size(), Ref<TerrainLight>());

	return _lights.get(index);
}
void TerrainWorld::light_remove(const int index) {
	ERR_FAIL_INDEX(index, _lights.size());

	Ref<TerrainLight> light = _lights[index];

	for (int i = 0; i < _chunks_vector.size(); ++i) {
		Ref<TerrainChunk> chunk = _chunks_vector[i];

		if (chunk.is_valid()) {
			chunk->world_light_removed(light);
		}
	}
}
int TerrainWorld::light_get_count() const {
	return _lights.size();
}
void TerrainWorld::lights_clear() {
	for (int i = 0; i < _lights.size(); ++i) {
		Ref<TerrainLight> light = _lights[i];

		if (!light.is_valid())
			continue;

		for (int j = 0; j < _chunks_vector.size(); ++j) {
			Ref<TerrainChunk> chunk = _chunks_vector[j];

			if (chunk.is_valid()) {
				chunk->world_light_removed(light);
			}
		}
	}

	_lights.clear();
}

Vector<Variant> TerrainWorld::lights_get() {
	VARIANT_ARRAY_GET(_lights);
}
void TerrainWorld::lights_set(const Vector<Variant> &chunks) {
	lights_clear();

	for (int i = 0; i < chunks.size(); ++i) {
		Ref<TerrainLight> light = Ref<TerrainLight>(chunks[i]);

		light_add(light);
	}
}

uint8_t TerrainWorld::get_voxel_at_world_position(const Vector3 &world_position, const int channel_index) {
	Vector3 pos = world_position / get_voxel_scale();

	//Note: floor is needed to handle negative numbers properly
	int x = static_cast<int>(Math::floor(pos.x / get_chunk_size_x()));
	int z = static_cast<int>(Math::floor(pos.z / get_chunk_size_z()));

	int bx = static_cast<int>(Math::floor(pos.x)) % get_chunk_size_x();
	int bz = static_cast<int>(Math::floor(pos.z)) % get_chunk_size_z();

	if (bx < 0) {
		bx += get_chunk_size_x();
	}

	if (bz < 0) {
		bz += get_chunk_size_z();
	}

	Ref<TerrainChunk> chunk = chunk_get(x, z);

	if (chunk.is_valid())
		return chunk->get_voxel(bx, bz, channel_index);

	return 0;
}

void TerrainWorld::set_voxel_at_world_position(const Vector3 &world_position, const uint8_t data, const int channel_index, const bool rebuild) {
	Vector3 pos = world_position / get_voxel_scale();

	//Note: floor is needed to handle negative numbers properly
	int x = static_cast<int>(Math::floor(pos.x / get_chunk_size_x()));
	int z = static_cast<int>(Math::floor(pos.z / get_chunk_size_z()));

	int bx = static_cast<int>(Math::floor(pos.x)) % get_chunk_size_x();
	int bz = static_cast<int>(Math::floor(pos.z)) % get_chunk_size_z();

	if (bx < 0) {
		bx += get_chunk_size_x();
	}

	if (bz < 0) {
		bz += get_chunk_size_z();
	}

	if (get_data_margin_end() > 0) {
		if (bx == 0) {
			Ref<TerrainChunk> chunk = chunk_get_or_create(x - 1, z);
			chunk->set_voxel(data, get_chunk_size_x(), bz, channel_index);

			if (rebuild)
				chunk->build();
		}

		if (bz == 0) {
			Ref<TerrainChunk> chunk = chunk_get_or_create(x, z - 1);
			chunk->set_voxel(data, bx, get_chunk_size_z(), channel_index);

			if (rebuild)
				chunk->build();
		}
	}

	if (get_data_margin_start() > 0) {
		if (bx == get_chunk_size_x() - 1) {
			Ref<TerrainChunk> chunk = chunk_get_or_create(x + 1, z);
			chunk->set_voxel(data, -1, bz, channel_index);

			if (rebuild)
				chunk->build();
		}

		if (bz == get_chunk_size_z() - 1) {
			Ref<TerrainChunk> chunk = chunk_get_or_create(x, z + 1);
			chunk->set_voxel(data, bx, -1, channel_index);

			if (rebuild)
				chunk->build();
		}
	}

	Ref<TerrainChunk> chunk = chunk_get_or_create(x, z);
	chunk->set_voxel(data, bx, bz, channel_index);

	if (rebuild)
		chunk->build();
}

Ref<TerrainChunk> TerrainWorld::get_chunk_at_world_position(const Vector3 &world_position) {
	Vector3 pos = world_position / get_voxel_scale();

	//Note: floor is needed to handle negative numbers proiberly
	int x = static_cast<int>(Math::floor(pos.x / get_chunk_size_x()));
	int z = static_cast<int>(Math::floor(pos.z / get_chunk_size_z()));

	return chunk_get(x, z);
}
Ref<TerrainChunk> TerrainWorld::get_or_create_chunk_at_world_position(const Vector3 &world_position) {
	Vector3 pos = world_position / get_voxel_scale();

	//Note: floor is needed to handle negative numbers proiberly
	int x = static_cast<int>(Math::floor(pos.x / get_chunk_size_x()));
	int z = static_cast<int>(Math::floor(pos.z / get_chunk_size_z()));

	return chunk_get_or_create(x, z);
}

void TerrainWorld::set_voxel_with_tool(const bool mode_add, const Vector3 hit_position, const Vector3 hit_normal, const int selected_voxel, const int isolevel) {
	call("_set_voxel_with_tool", mode_add, hit_position, hit_normal, selected_voxel, isolevel);
}

int TerrainWorld::get_channel_index_info(const TerrainWorld::ChannelTypeInfo channel_type) {
	return call("_get_channel_index_info", channel_type);
}

Spatial *TerrainWorld::get_editor_camera() {
#if TOOLS_ENABLED
	SpatialEditor *se = SpatialEditor::get_singleton();

	if (!se) {
		return nullptr;
	}

	SpatialEditorViewport *wp = se->get_editor_viewport(0);

	if (!wp) {
		return nullptr;
	}

	return wp->get_camera();

#else
	return nullptr;
#endif
}

TerrainWorld::TerrainWorld() {
	_active = true;
	_editable = false;

	_is_priority_generation = true;
	_max_concurrent_generations = 3;

	_chunk_size_x = 16;
	_chunk_size_z = 16;
	_current_seed = 0;
	_data_margin_start = 0;
	_data_margin_end = 0;
	_world_height = 256;

	_voxel_scale = 1;
	_chunk_spawn_range = 4;

	_player = NULL;
	_max_frame_chunk_build_steps = 0;
	_num_frame_chunk_build_steps = 0;
}

TerrainWorld ::~TerrainWorld() {
	_chunks.clear();
	_chunks_vector.clear();
	_world_areas.clear();
	_voxel_structures.clear();

	_library.unref();
	_level_generator.unref();

	_player = NULL;

	_generation_queue.clear();
	_generating.clear();

	_lights.clear();
}

void TerrainWorld::_generate_chunk(Ref<TerrainChunk> chunk) {
	ERR_FAIL_COND(!chunk.is_valid());

	if (_level_generator.is_valid())
		_level_generator->generate_chunk(chunk);

	for (int i = 0; i < _voxel_structures.size(); ++i) {
		Ref<TerrainStructure> structure = _voxel_structures.get(i);

		if (!structure.is_valid())
			continue;

		if (structure->get_use_aabb()) {
			if (structure->get_chunk_aabb().has_point(Vector3(chunk->get_position_x(), 1, chunk->get_position_z())))
				structure->write_to_chunk(chunk);
		} else {
			structure->write_to_chunk(chunk);
		}
	}
}

void TerrainWorld::_notification(int p_what) {
	switch (p_what) {
		case NOTIFICATION_ENTER_TREE: {
			set_player_bind(get_node_or_null(get_player_path()));

			set_process_internal(true);
			set_physics_process_internal(true);
			set_notify_transform(true);

			if (_library.is_valid())
				_library->refresh_rects();

			for (int i = 0; i < _chunks_vector.size(); ++i) {
				Ref<TerrainChunk> chunk = _chunks_vector[i];

				if (chunk.is_valid()) {
					chunk_setup(chunk);

					chunk->build();
				}
			}
			break;
		}
		case NOTIFICATION_INTERNAL_PROCESS: {
			_num_frame_chunk_build_steps = 0;

			for (int i = 0; i < _chunks_vector.size(); ++i) {
				Ref<TerrainChunk> chunk = _chunks_vector[i];

				ERR_CONTINUE(!chunk.is_valid());

				if (chunk->get_process()) {
					chunk->process(get_process_delta_time());
				}

				if (chunk->get_is_generating()) {
					chunk->generation_process(get_process_delta_time());
				}
			}

			if (_is_priority_generation && _generation_queue.empty() && _generating.empty()) {
				_is_priority_generation = false;

				call("_generation_finished");

				emit_signal("generation_finished");

				return;
			}

			for (int i = 0; i < _generating.size(); ++i) {
				Ref<TerrainChunk> chunk = _generating.get(i);

				if (!chunk.is_valid()) {
					_generating.remove(i);
					--i;
					continue;
				}

				if (!chunk->get_is_generating()) {
					_generating.remove(i);
					--i;
					continue;
				}

				if (chunk->is_build_aborted() && chunk->is_safe_to_delete()) {
					_generating.remove(i);
					--i;
					continue;
				}
			}

			if (_generating.size() >= _max_concurrent_generations)
				return;

			if (_generation_queue.size() == 0)
				return;

			while (_generating.size() < _max_concurrent_generations && _generation_queue.size() != 0) {
				Ref<TerrainChunk> chunk = _generation_queue.get(0);
				_generation_queue.remove(0);

				ERR_FAIL_COND(!chunk.is_valid());

				_generating.push_back(chunk);

				chunk_generate(chunk);
			}
			break;
		}
		case NOTIFICATION_INTERNAL_PHYSICS_PROCESS: {
			for (int i = 0; i < _chunks_vector.size(); ++i) {
				Ref<TerrainChunk> chunk = _chunks_vector[i];

				ERR_CONTINUE(!chunk.is_valid());

				if (chunk->get_process()) {
					chunk->physics_process(get_physics_process_delta_time());
				}

				if (chunk->get_is_generating()) {
					chunk->generation_physics_process(get_physics_process_delta_time());
				}
			}
			break;
		}
		case NOTIFICATION_EXIT_TREE: {
			for (int i = 0; i < _chunks_vector.size(); ++i) {
				Ref<TerrainChunk> chunk = _chunks_vector[i];

				if (chunk.is_valid()) {
					if (chunk->get_voxel_world() == this) {
						chunk->exit_tree();
						chunk->set_voxel_world(NULL);
					}
				}
			}
			break;
		}
		case NOTIFICATION_TRANSFORM_CHANGED: {
			for (int i = 0; i < _chunks_vector.size(); ++i) {
				Ref<TerrainChunk> chunk = _chunks_vector[i];

				if (chunk.is_valid()) {
					chunk->world_transform_changed();
				}
			}
			break;
		}
	}
}

void TerrainWorld::_bind_methods() {
	ADD_SIGNAL(MethodInfo("chunk_mesh_generation_finished", PropertyInfo(Variant::OBJECT, "chunk", PROPERTY_HINT_RESOURCE_TYPE, "TerrainChunk")));
	ADD_SIGNAL(MethodInfo("chunk_added", PropertyInfo(Variant::OBJECT, "chunk", PROPERTY_HINT_RESOURCE_TYPE, "TerrainChunk")));
	ADD_SIGNAL(MethodInfo("chunk_removed", PropertyInfo(Variant::OBJECT, "chunk", PROPERTY_HINT_RESOURCE_TYPE, "TerrainChunk")));

	ClassDB::bind_method(D_METHOD("get_active"), &TerrainWorld::get_active);
	ClassDB::bind_method(D_METHOD("set_active", "value"), &TerrainWorld::set_active);
	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "active"), "set_active", "get_active");

	ClassDB::bind_method(D_METHOD("get_editable"), &TerrainWorld::get_editable);
	ClassDB::bind_method(D_METHOD("set_editable", "value"), &TerrainWorld::set_editable);
	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "editable"), "set_editable", "get_editable");

	ClassDB::bind_method(D_METHOD("get_chunk_size_x"), &TerrainWorld::get_chunk_size_x);
	ClassDB::bind_method(D_METHOD("set_chunk_size_x", "value"), &TerrainWorld::set_chunk_size_x);
	ADD_PROPERTY(PropertyInfo(Variant::INT, "chunk_size_x"), "set_chunk_size_x", "get_chunk_size_x");

	ClassDB::bind_method(D_METHOD("get_chunk_size_z"), &TerrainWorld::get_chunk_size_z);
	ClassDB::bind_method(D_METHOD("set_chunk_size_z", "value"), &TerrainWorld::set_chunk_size_z);
	ADD_PROPERTY(PropertyInfo(Variant::INT, "chunk_size_z"), "set_chunk_size_z", "get_chunk_size_z");

	ClassDB::bind_method(D_METHOD("get_data_margin_start"), &TerrainWorld::get_data_margin_start);
	ClassDB::bind_method(D_METHOD("set_data_margin_start", "value"), &TerrainWorld::set_data_margin_start);
	ADD_PROPERTY(PropertyInfo(Variant::INT, "data_margin_start"), "set_data_margin_start", "get_data_margin_start");

	ClassDB::bind_method(D_METHOD("get_data_margin_end"), &TerrainWorld::get_data_margin_end);
	ClassDB::bind_method(D_METHOD("set_data_margin_end", "value"), &TerrainWorld::set_data_margin_end);
	ADD_PROPERTY(PropertyInfo(Variant::INT, "data_margin_end"), "set_data_margin_end", "get_data_margin_end");

	ClassDB::bind_method(D_METHOD("get_world_height"), &TerrainWorld::get_world_height);
	ClassDB::bind_method(D_METHOD("set_world_height", "height"), &TerrainWorld::set_world_height);
	ADD_PROPERTY(PropertyInfo(Variant::REAL, "world_height"), "set_world_height", "get_world_height");

	ClassDB::bind_method(D_METHOD("get_max_concurrent_generations"), &TerrainWorld::get_max_concurrent_generations);
	ClassDB::bind_method(D_METHOD("set_max_concurrent_generations", "height"), &TerrainWorld::set_max_concurrent_generations);
	ADD_PROPERTY(PropertyInfo(Variant::INT, "max_concurrent_generations"), "set_max_concurrent_generations", "get_max_concurrent_generations");

	ClassDB::bind_method(D_METHOD("get_current_seed"), &TerrainWorld::get_current_seed);
	ClassDB::bind_method(D_METHOD("set_current_seed", "value"), &TerrainWorld::set_current_seed);
	ADD_PROPERTY(PropertyInfo(Variant::INT, "current_seed"), "set_current_seed", "get_current_seed");

	ClassDB::bind_method(D_METHOD("get_library"), &TerrainWorld::get_library);
	ClassDB::bind_method(D_METHOD("set_library", "library"), &TerrainWorld::set_library);
	ADD_PROPERTY(PropertyInfo(Variant::OBJECT, "library", PROPERTY_HINT_RESOURCE_TYPE, "TerrainLibrary"), "set_library", "get_library");

	ClassDB::bind_method(D_METHOD("get_level_generator"), &TerrainWorld::get_level_generator);
	ClassDB::bind_method(D_METHOD("set_level_generator", "level_generator"), &TerrainWorld::set_level_generator);
	ADD_PROPERTY(PropertyInfo(Variant::OBJECT, "level_generator", PROPERTY_HINT_RESOURCE_TYPE, "TerrainLevelGenerator"), "set_level_generator", "get_level_generator");

	ClassDB::bind_method(D_METHOD("get_voxel_scale"), &TerrainWorld::get_voxel_scale);
	ClassDB::bind_method(D_METHOD("set_voxel_scale", "value"), &TerrainWorld::set_voxel_scale);
	ADD_PROPERTY(PropertyInfo(Variant::REAL, "voxel_scale"), "set_voxel_scale", "get_voxel_scale");

	ClassDB::bind_method(D_METHOD("get_chunk_spawn_range"), &TerrainWorld::get_chunk_spawn_range);
	ClassDB::bind_method(D_METHOD("set_chunk_spawn_range", "value"), &TerrainWorld::set_chunk_spawn_range);
	ADD_PROPERTY(PropertyInfo(Variant::INT, "chunk_spawn_range"), "set_chunk_spawn_range", "get_chunk_spawn_range");

	ClassDB::bind_method(D_METHOD("get_player_path"), &TerrainWorld::get_player_path);
	ClassDB::bind_method(D_METHOD("set_player_path", "value"), &TerrainWorld::set_player_path);
	ADD_PROPERTY(PropertyInfo(Variant::NODE_PATH, "player_path"), "set_player_path", "get_player_path");

	ClassDB::bind_method(D_METHOD("get_player"), &TerrainWorld::get_player);
	ClassDB::bind_method(D_METHOD("set_player", "player"), &TerrainWorld::set_player_bind);
	ADD_PROPERTY(PropertyInfo(Variant::OBJECT, "player", PROPERTY_HINT_RESOURCE_TYPE, "Spatial", 0), "set_player", "get_player");

	ClassDB::bind_method(D_METHOD("world_area_get", "index"), &TerrainWorld::world_area_get);
	ClassDB::bind_method(D_METHOD("world_area_add", "area"), &TerrainWorld::world_area_add);
	ClassDB::bind_method(D_METHOD("world_area_remove", "index"), &TerrainWorld::world_area_remove);
	ClassDB::bind_method(D_METHOD("world_areas_clear"), &TerrainWorld::world_areas_clear);
	ClassDB::bind_method(D_METHOD("world_area_get_count"), &TerrainWorld::world_area_get_count);

	ClassDB::bind_method(D_METHOD("voxel_structure_get", "index"), &TerrainWorld::voxel_structure_get);
	ClassDB::bind_method(D_METHOD("voxel_structure_add", "structure"), &TerrainWorld::voxel_structure_add);
	ClassDB::bind_method(D_METHOD("voxel_structure_remove", "structure"), &TerrainWorld::voxel_structure_remove);
	ClassDB::bind_method(D_METHOD("voxel_structure_remove_index", "index"), &TerrainWorld::voxel_structure_remove_index);
	ClassDB::bind_method(D_METHOD("voxel_structures_clear"), &TerrainWorld::voxel_structures_clear);
	ClassDB::bind_method(D_METHOD("voxel_structure_get_count"), &TerrainWorld::voxel_structure_get_count);
	ClassDB::bind_method(D_METHOD("voxel_structure_add_at_position", "structure", "world_position"), &TerrainWorld::voxel_structure_add_at_position);

	ClassDB::bind_method(D_METHOD("voxel_structures_get"), &TerrainWorld::voxel_structures_get);
	ClassDB::bind_method(D_METHOD("voxel_structures_set"), &TerrainWorld::voxel_structures_set);
	ADD_PROPERTY(PropertyInfo(Variant::ARRAY, "voxel_structures", PROPERTY_HINT_NONE, "23/20:TerrainStructure", PROPERTY_USAGE_DEFAULT, "TerrainStructure"), "voxel_structures_set", "voxel_structures_get");

	BIND_VMETHOD(MethodInfo("_chunk_added", PropertyInfo(Variant::OBJECT, "chunk", PROPERTY_HINT_RESOURCE_TYPE, "TerrainChunk")));

	ClassDB::bind_method(D_METHOD("chunk_add", "chunk", "x", "z"), &TerrainWorld::chunk_add);
	ClassDB::bind_method(D_METHOD("chunk_has", "x", "z"), &TerrainWorld::chunk_has);
	ClassDB::bind_method(D_METHOD("chunk_get", "x", "z"), &TerrainWorld::chunk_get);
	ClassDB::bind_method(D_METHOD("chunk_remove", "x", "z"), &TerrainWorld::chunk_remove);
	ClassDB::bind_method(D_METHOD("chunk_remove_index", "index"), &TerrainWorld::chunk_remove_index);

	ClassDB::bind_method(D_METHOD("chunk_get_index", "index"), &TerrainWorld::chunk_get_index);
	ClassDB::bind_method(D_METHOD("chunk_get_count"), &TerrainWorld::chunk_get_count);

	ClassDB::bind_method(D_METHOD("chunks_clear"), &TerrainWorld::chunks_clear);

	ClassDB::bind_method(D_METHOD("chunks_get"), &TerrainWorld::chunks_get);
	ClassDB::bind_method(D_METHOD("chunks_set"), &TerrainWorld::chunks_set);
	ADD_PROPERTY(PropertyInfo(Variant::ARRAY, "chunks", PROPERTY_HINT_NONE, "23/20:TerrainChunk", PROPERTY_USAGE_DEFAULT, "TerrainChunk"), "chunks_set", "chunks_get");

	ClassDB::bind_method(D_METHOD("generation_queue_add_to", "chunk"), &TerrainWorld::generation_queue_add_to);
	ClassDB::bind_method(D_METHOD("generation_queue_get_index", "index"), &TerrainWorld::generation_queue_get_index);
	ClassDB::bind_method(D_METHOD("generation_queue_remove_index", "index"), &TerrainWorld::generation_queue_remove_index);
	ClassDB::bind_method(D_METHOD("generation_queue_get_size"), &TerrainWorld::generation_queue_get_size);

	ClassDB::bind_method(D_METHOD("generation_add_to", "chunk"), &TerrainWorld::generation_add_to);
	ClassDB::bind_method(D_METHOD("generation_get_index", "index"), &TerrainWorld::generation_get_index);
	ClassDB::bind_method(D_METHOD("generation_remove_index", "index"), &TerrainWorld::generation_remove_index);
	ClassDB::bind_method(D_METHOD("generation_get_size"), &TerrainWorld::generation_get_size);

	ADD_SIGNAL(MethodInfo("generation_finished"));

	BIND_VMETHOD(MethodInfo("_generation_finished"));

	BIND_VMETHOD(MethodInfo(PropertyInfo(Variant::OBJECT, "ret", PROPERTY_HINT_RESOURCE_TYPE, "TerrainChunk"), "_create_chunk", PropertyInfo(Variant::INT, "x"), PropertyInfo(Variant::INT, "z"), PropertyInfo(Variant::OBJECT, "chunk", PROPERTY_HINT_RESOURCE_TYPE, "TerrainChunk")));
	BIND_VMETHOD(MethodInfo("_prepare_chunk_for_generation", PropertyInfo(Variant::OBJECT, "chunk", PROPERTY_HINT_RESOURCE_TYPE, "TerrainChunk")));
	BIND_VMETHOD(MethodInfo("_generate_chunk", PropertyInfo(Variant::OBJECT, "chunk", PROPERTY_HINT_RESOURCE_TYPE, "TerrainChunk")));

	ClassDB::bind_method(D_METHOD("chunk_get_or_create", "x", "z"), &TerrainWorld::chunk_get_or_create);
	ClassDB::bind_method(D_METHOD("chunk_create", "x", "z"), &TerrainWorld::chunk_create);
	ClassDB::bind_method(D_METHOD("chunk_setup", "chunk"), &TerrainWorld::chunk_setup);

	ClassDB::bind_method(D_METHOD("_create_chunk", "x", "z", "chunk"), &TerrainWorld::_create_chunk);
	ClassDB::bind_method(D_METHOD("_generate_chunk", "chunk"), &TerrainWorld::_generate_chunk);

	ClassDB::bind_method(D_METHOD("can_chunk_do_build_step"), &TerrainWorld::can_chunk_do_build_step);
	ClassDB::bind_method(D_METHOD("is_position_walkable", "position"), &TerrainWorld::is_position_walkable);
	ClassDB::bind_method(D_METHOD("on_chunk_mesh_generation_finished", "chunk"), &TerrainWorld::on_chunk_mesh_generation_finished);

#ifdef MODULE_PROPS_ENABLED
	ClassDB::bind_method(D_METHOD("prop_add", "transform", "prop", "apply_voxel_scale"), &TerrainWorld::prop_add, DEFVAL(true));
#endif

	//Lights
	ClassDB::bind_method(D_METHOD("light_add", "light"), &TerrainWorld::light_add);
	ClassDB::bind_method(D_METHOD("light_get", "index"), &TerrainWorld::light_get);
	ClassDB::bind_method(D_METHOD("light_remove", "index"), &TerrainWorld::light_remove);
	ClassDB::bind_method(D_METHOD("light_get_count"), &TerrainWorld::light_get_count);
	ClassDB::bind_method(D_METHOD("lights_clear"), &TerrainWorld::lights_clear);

	ClassDB::bind_method(D_METHOD("lights_get"), &TerrainWorld::lights_get);
	ClassDB::bind_method(D_METHOD("lights_set", "chunks"), &TerrainWorld::lights_set);

	ClassDB::bind_method(D_METHOD("get_voxel_at_world_position", "world_position", "channel_index"), &TerrainWorld::get_voxel_at_world_position);
	ClassDB::bind_method(D_METHOD("set_voxel_at_world_position", "world_position", "data", "channel_index", "rebuild"), &TerrainWorld::set_voxel_at_world_position, DEFVAL(true));
	ClassDB::bind_method(D_METHOD("get_chunk_at_world_position", "world_position"), &TerrainWorld::get_chunk_at_world_position);
	ClassDB::bind_method(D_METHOD("get_or_create_chunk_at_world_position", "world_position"), &TerrainWorld::get_or_create_chunk_at_world_position);

	BIND_VMETHOD(MethodInfo(PropertyInfo(Variant::INT, "ret"), "_get_channel_index_info", PropertyInfo(Variant::INT, "channel_type", PROPERTY_HINT_ENUM, BINDING_STRING_CHANNEL_TYPE_INFO)));

	ClassDB::bind_method(D_METHOD("get_channel_index_info", "channel_type"), &TerrainWorld::get_channel_index_info);
	ClassDB::bind_method(D_METHOD("_get_channel_index_info", "channel_type"), &TerrainWorld::_get_channel_index_info);

	ClassDB::bind_method(D_METHOD("get_editor_camera"), &TerrainWorld::get_editor_camera);

	BIND_VMETHOD(MethodInfo("_set_voxel_with_tool",
			PropertyInfo(Variant::BOOL, "mode_add"),
			PropertyInfo(Variant::VECTOR3, "hit_position"),
			PropertyInfo(Variant::VECTOR3, "hit_normal"),
			PropertyInfo(Variant::INT, "selected_voxel"),
			PropertyInfo(Variant::INT, "isolevel")));

	ClassDB::bind_method(D_METHOD("set_voxel_with_tool", "mode_add", "hit_position", "hit_normal", "selected_voxel", "isolevel"), &TerrainWorld::set_voxel_with_tool);
	ClassDB::bind_method(D_METHOD("_set_voxel_with_tool", "mode_add", "hit_position", "hit_normal", "selected_voxel", "isolevel"), &TerrainWorld::_set_voxel_with_tool);

	BIND_ENUM_CONSTANT(CHANNEL_TYPE_INFO_TYPE);
	BIND_ENUM_CONSTANT(CHANNEL_TYPE_INFO_ISOLEVEL);
	BIND_ENUM_CONSTANT(CHANNEL_TYPE_INFO_LIQUID_FLOW);

	BIND_CONSTANT(NOTIFICATION_ACTIVE_STATE_CHANGED);
}