#ifndef TERRAIN_WORLD_H
#define TERRAIN_WORLD_H


#include "core/config/engine.h"
#include "core/containers/hash_map.h"

#include "../defines.h"

#include "scene/main/spatial.h"

#include "../areas/terrain_world_area.h"
#include "../level_generator/terrain_level_generator.h"
#include "../library/terrain_library.h"

#include "core/os/os.h"

#include "modules/modules_enabled.gen.h"

#ifdef MODULE_PROPS_ENABLED
#include "../../props/props/prop_data.h"
#endif

class TerrainStructure;
class TerrainChunk;
class PropData;

class TerrainWorld : public Spatial {
	GDCLASS(TerrainWorld, Spatial);

public:
	enum ChannelTypeInfo {
		CHANNEL_TYPE_INFO_TYPE = 0,
		CHANNEL_TYPE_INFO_ISOLEVEL,
		CHANNEL_TYPE_INFO_LIQUID_FLOW,
	};

	enum {
		NOTIFICATION_ACTIVE_STATE_CHANGED = 9000,
	};

	static const String BINDING_STRING_CHANNEL_TYPE_INFO;

public:
	bool get_active() const;
	void set_active(const bool value);

	bool get_editable() const;
	void set_editable(const bool value);

	int get_chunk_size_x() const;
	void set_chunk_size_x(const int value);

	int get_chunk_size_z() const;
	void set_chunk_size_z(const int value);

	int get_data_margin_start() const;
	void set_data_margin_start(const int value);

	int get_data_margin_end() const;
	void set_data_margin_end(const int value);

	int get_current_seed() const;
	void set_current_seed(const int value);

	float get_world_height() const;
	void set_world_height(const float value);

	int get_max_concurrent_generations();
	void set_max_concurrent_generations(const int value);

	Ref<TerrainLibrary> get_library();
	void set_library(const Ref<TerrainLibrary> &library);

	Ref<TerrainLevelGenerator> get_level_generator() const;
	void set_level_generator(const Ref<TerrainLevelGenerator> &level_generator);

	float get_voxel_scale() const;
	void set_voxel_scale(const float value);

	int get_chunk_spawn_range() const;
	void set_chunk_spawn_range(const int value);

	NodePath get_player_path() const;
	void set_player_path(const NodePath &player_path);

	Spatial *get_player() const;
	void set_player(Spatial *player);
	void set_player_bind(Node *player);

	//World Areas
	Ref<TerrainWorldArea> world_area_get(const int index) const;
	void world_area_add(const Ref<TerrainWorldArea> &area);
	void world_area_remove(const int index);
	void world_areas_clear();
	int world_area_get_count() const;

	//Terra Structures
	Ref<TerrainStructure> voxel_structure_get(const int index) const;
	void voxel_structure_add(const Ref<TerrainStructure> &structure);
	void voxel_structure_remove(const Ref<TerrainStructure> &structure);
	void voxel_structure_remove_index(const int index);
	void voxel_structures_clear();
	int voxel_structure_get_count() const;
	void voxel_structure_add_at_position(Ref<TerrainStructure> structure, const Vector3 &world_position);

	Vector<Variant> voxel_structures_get();
	void voxel_structures_set(const Vector<Variant> &structures);

	//Chunks
	void chunk_add(Ref<TerrainChunk> chunk, const int x, const int z);
	bool chunk_has(const int x, const int z) const;
	Ref<TerrainChunk> chunk_get(const int x, const int z);
	Ref<TerrainChunk> chunk_remove(const int x, const int z);
	Ref<TerrainChunk> chunk_remove_index(const int index);
	Ref<TerrainChunk> chunk_get_index(const int index);

	int chunk_get_count() const;

	void chunks_clear();

	Ref<TerrainChunk> chunk_get_or_create(const int x, const int z);
	Ref<TerrainChunk> chunk_create(const int x, const int z);
	void chunk_setup(Ref<TerrainChunk> chunk);

	void chunk_generate(Ref<TerrainChunk> chunk);

	Vector<Variant> chunks_get();
	void chunks_set(const Vector<Variant> &chunks);

	bool can_chunk_do_build_step();
	bool is_position_walkable(const Vector3 &p_pos);

	void on_chunk_mesh_generation_finished(Ref<TerrainChunk> p_chunk);

	void generation_queue_add_to(const Ref<TerrainChunk> &chunk);
	Ref<TerrainChunk> generation_queue_get_index(const int index);
	void generation_queue_remove_index(const int index);
	int generation_queue_get_size() const;

	void generation_add_to(const Ref<TerrainChunk> &chunk);
	Ref<TerrainChunk> generation_get_index(const int index);
	void generation_remove_index(const int index);
	int generation_get_size() const;

#ifdef MODULE_PROPS_ENABLED
	void prop_add(Transform transform, const Ref<PropData> &prop, const bool apply_voxel_scale = true);
#endif

	//Lights
	void light_add(const Ref<TerrainLight> &light);
	Ref<TerrainLight> light_get(const int index);
	void light_remove(const int index);
	int light_get_count() const;
	void lights_clear();

	Vector<Variant> lights_get();
	void lights_set(const Vector<Variant> &chunks);

	//Helpers
	uint8_t get_voxel_at_world_position(const Vector3 &world_position, const int channel_index);
	void set_voxel_at_world_position(const Vector3 &world_position, const uint8_t data, const int channel_index, const bool rebuild = true);
	Ref<TerrainChunk> get_chunk_at_world_position(const Vector3 &world_position);
	Ref<TerrainChunk> get_or_create_chunk_at_world_position(const Vector3 &world_position);
	void set_voxel_with_tool(const bool mode_add, const Vector3 hit_position, const Vector3 hit_normal, const int selected_voxel, const int isolevel);

	int get_channel_index_info(const ChannelTypeInfo channel_type);

	Spatial *get_editor_camera();

	TerrainWorld();
	~TerrainWorld();

protected:
	virtual void _generate_chunk(Ref<TerrainChunk> chunk);
	virtual Ref<TerrainChunk> _create_chunk(int x, int z, Ref<TerrainChunk> p_chunk);
	virtual int _get_channel_index_info(const ChannelTypeInfo channel_type);
	virtual void _set_voxel_with_tool(const bool mode_add, const Vector3 hit_position, const Vector3 hit_normal, const int selected_voxel, const int isolevel);

	virtual void _notification(int p_what);
	static void _bind_methods();

public:
	struct IntPos {
		int x;
		int z;

		IntPos() {
			x = 0;
			z = 0;
		}

		IntPos(int p_x, int p_z) {
			x = p_x;
			z = p_z;
		}

		IntPos(const Vector2 &p) {
			x = p.x;
			z = p.y;
		}
	};

	struct IntPosHasher {
		static _FORCE_INLINE_ uint32_t hash(const IntPos &v) {
			uint32_t hash = hash_djb2_one_32(v.x);
			hash = hash_djb2_one_32(v.x, hash);
			return hash_djb2_one_32(v.z, hash);
		}
	};

private:
	bool _active;
	bool _editable;

	bool _is_priority_generation;

	int _chunk_size_x;
	int _chunk_size_z;
	int _current_seed;
	int _data_margin_start;
	int _data_margin_end;
	float _world_height;

	Ref<TerrainLibrary> _library;
	Ref<TerrainLevelGenerator> _level_generator;
	float _voxel_scale;
	int _chunk_spawn_range;

	HashMap<IntPos, Ref<TerrainChunk>, IntPosHasher> _chunks;
	Vector<Ref<TerrainChunk>> _chunks_vector;

	Vector<Ref<TerrainWorldArea>> _world_areas;

	Vector<Ref<TerrainStructure>> _voxel_structures;

	NodePath _player_path;
	Spatial *_player;

	int _max_concurrent_generations;
	Vector<Ref<TerrainChunk>> _generation_queue;
	Vector<Ref<TerrainChunk>> _generating;
	int _max_frame_chunk_build_steps;
	int _num_frame_chunk_build_steps;

	Vector<Ref<TerrainLight>> _lights;
};

_FORCE_INLINE_ bool operator==(const TerrainWorld::IntPos &a, const TerrainWorld::IntPos &b) {
	return a.x == b.x && a.z == b.z;
}

VARIANT_ENUM_CAST(TerrainWorld::ChannelTypeInfo);

#endif