#@tool
extends Node3D
const CENTER := Vector3.ZERO
@export var RADIUS: float = 5.0

var sample_points = {}
var SamplePoint = preload("res://sample_point.gd")
var surface_points = {}
var SurfacePoint = preload("res://surface_point.gd")
var ComputeSdf = preload("res://compute_test.gd")
var gpu_sdf

var generate_mesh_shader = preload("res://generate_mesh.tres")

var regenerate_mesh = false


@export var world_size = 16
@export var show_sample_points = false
@export var show_surface_points = false
@export var show_surface = true

@export var do_the_thing: bool = false
@export var clear_the_thing: bool = false

var color = Color.CORAL
var surface_point_color = Color.CRIMSON

var mesh
var surface_tool: SurfaceTool = SurfaceTool.new()

var meshinstance = MeshInstance3D.new()
var material = ShaderMaterial.new()

func _ready() -> void:
	material.shader = generate_mesh_shader
	meshinstance.material_override = material
	add_child(meshinstance)
	gpu_sdf = ComputeSdf.new()
	gpu_sdf.create_device()
	var dictionaries = gpu_sdf.compute(world_size, RADIUS)
	surface_points = dictionaries.surface_points_dict
	sample_points = dictionaries.sample_points_dict
	create_surface_mesh()

func _process(_delta: float) -> void:
	
	if !surface_points.is_empty():
		#create_surface_points_gpu()
		#create_surface_points()
		if show_surface_points:
			draw_surface_points()
		if show_surface && regenerate_mesh:
			clear()
			var dictionaries = gpu_sdf.compute(world_size, RADIUS)
			surface_points = dictionaries.surface_points_dict
			sample_points = dictionaries.sample_points_dict
			create_surface_mesh()
		if show_sample_points:
			draw_sample_points()
	

func clear():
	surface_points = {}
	sample_points = {}
	mesh = ArrayMesh.new()


func get_index_from_coords(coords: Vector3i):
	return coords.x + coords.y * world_size + coords.z * world_size * world_size

func draw_sample_points():
	for x in range(world_size):
		for y in range(world_size):
			for z in range(world_size):
				if sample_points.has(Vector3i(x, y, z)):
					DebugDraw3D.draw_square(Vector3i(x, y, z), 0.2, color)
					#DebugDraw3D.draw_text(Vector3i(x, y, z), str(Vector3i(x, y, z)))

func draw_surface_points():
	for surface_point in surface_points:
		if surface_points[surface_point] != Vector3(0, 0, 0):
			DebugDraw3D.draw_square(surface_points[surface_point] , 0.3, surface_point_color)
			DebugDraw3D.draw_text(surface_points[surface_point], str(surface_points[surface_point]))

func calculate_surface_point_position(voxel: Vector3i):
	var final_point = Vector3(voxel)
	return final_point

func create_surface_mesh():
	surface_tool = SurfaceTool.new()
	surface_tool.begin(Mesh.PRIMITIVE_TRIANGLES)
	for x in range(world_size):
		for y in range(world_size):
			for z in range(world_size):
				if surface_points.has(Vector3i(x, y, z)):
					create_surface_mesh_quad(Vector3i(x,y,z));
	mesh = surface_tool.commit()
	meshinstance.mesh = mesh

func create_surface_mesh_quad(index: Vector3i):
	for axis_index in range(AXIS.size()):
		var axis = AXIS[axis_index]
		if sample_points.has(index + axis):
			var sample_value1 = sample_points[index]
			var sample_value2 = sample_points[index + axis]

			if sample_value1 < 0 and sample_value2 >= 0:
				add_quad(index, axis_index)
			elif sample_value1 >= 0 and sample_value2 < 0:
				add_reversed_quad(index, axis_index)

const AXIS := [
	Vector3i(1,0,0), 
	Vector3i(0,1,0), 
	Vector3i(0,0,1), 
]

const SURFACE_AXIS := [
	Vector3i(1,0,0),
	Vector3i(0,1,0),
	Vector3i(0,0,1),
	Vector3i(1,0,1),
	Vector3i(0,1,1),
	Vector3i(1,1,0),
	Vector3i(1,1,1),
	Vector3i(0,0,0),
]

func add_quad(index: Vector3i, axis_index: int):
	var points = get_quad_points(index, axis_index)
	if points != null:
		surface_tool.add_vertex(points[0])
		surface_tool.add_vertex(points[1])
		surface_tool.add_vertex(points[2])

		surface_tool.add_vertex(points[0])
		surface_tool.add_vertex(points[2])
		surface_tool.add_vertex(points[3])
		surface_tool.generate_normals()

func add_reversed_quad(index: Vector3i, axis_index: int):
	var points = get_quad_points(index, axis_index)

	if points != null:
		surface_tool.add_vertex(points[0])
		surface_tool.add_vertex(points[2])
		surface_tool.add_vertex(points[1])

		surface_tool.add_vertex(points[0])
		surface_tool.add_vertex(points[3])
		surface_tool.add_vertex(points[2])
		surface_tool.generate_normals()

func get_quad_points(index: Vector3i, axis_index: int):
	if surface_points.has(index + QUAD_POINTS[axis_index][0]) and surface_points.has(index + QUAD_POINTS[axis_index][1]) and surface_points.has(index + QUAD_POINTS[axis_index][2]) and surface_points.has(index + QUAD_POINTS[axis_index][3]):
		return [
			surface_points[index + QUAD_POINTS[axis_index][0]],
			surface_points[index + QUAD_POINTS[axis_index][1]],
			surface_points[index + QUAD_POINTS[axis_index][2]],
			surface_points[index + QUAD_POINTS[axis_index][3]],
		]

const QUAD_POINTS := [
	# x axis
	[
		Vector3i(0,0,-1),
		Vector3i(0,-1,-1),
		Vector3i(0,-1,0),
		Vector3i(0,0,0)
	], 
	# y axis
	[
		Vector3i(0,0,-1),
		Vector3i(0,0,0),
		Vector3i(-1,0,0),
		Vector3i(-1,0,-1)
	], 
	# z axis
	[
		Vector3i(0,0,0),
		Vector3i(0,-1,0),
		Vector3i(-1,-1,0),
		Vector3i(-1,0,0)
	], 
]