@tool
class_name ProceduralCloudTexture
extends Resource

@export var size: int = 512
@export var octaves: int = 6
@export var persistence: float = 0.5
@export var lacunarity: float = 2.0
@export var scale: float = 4.0
@export var seed_value: int = 0
@export var cloud_threshold: float = 0.4
@export var cloud_softness: float = 0.3

var _noise: FastNoiseLite
var _texture: ImageTexture


func _init() -> void:
	_setup_noise()


func _setup_noise() -> void:
	_noise = FastNoiseLite.new()
	_noise.noise_type = FastNoiseLite.TYPE_SIMPLEX
	_noise.seed = seed_value
	_noise.frequency = 1.0 / (scale * 64.0)
	_noise.fractal_type = FastNoiseLite.FRACTAL_FBM
	_noise.fractal_octaves = octaves
	_noise.fractal_lacunarity = lacunarity
	_noise.fractal_gain = persistence


func generate() -> ImageTexture:
	_setup_noise()
	
	var image := Image.create(size, size, false, Image.FORMAT_RGBA8)
	
	for y in size:
		for x in size:
			var noise_value := (_noise.get_noise_2d(float(x), float(y)) + 1.0) * 0.5
			
			var cloud_value := smoothstep(cloud_threshold - cloud_softness, cloud_threshold + cloud_softness, noise_value)
			
			var color := Color(cloud_value, cloud_value, cloud_value, cloud_value)
			image.set_pixel(x, y, color)
	
	_texture = ImageTexture.create_from_image(image)
	return _texture


func get_texture() -> ImageTexture:
	if _texture == null:
		return generate()
	return _texture


static func create_default_cloud_texture(layer_type: int = 0) -> ImageTexture:
	var generator := ProceduralCloudTexture.new()
	generator.size = 512
	
	match layer_type:
		0:  # Low clouds - larger, denser
			generator.scale = 3.0
			generator.octaves = 4
			generator.cloud_threshold = 0.35
			generator.cloud_softness = 0.25
		1:  # Mid clouds - medium
			generator.scale = 4.0
			generator.octaves = 5
			generator.cloud_threshold = 0.4
			generator.cloud_softness = 0.3
		2:  # High clouds - wispy
			generator.scale = 6.0
			generator.octaves = 6
			generator.cloud_threshold = 0.5
			generator.cloud_softness = 0.35
		3:  # Wisps - very thin
			generator.scale = 8.0
			generator.octaves = 7
			generator.cloud_threshold = 0.55
			generator.cloud_softness = 0.4
	
	return generator.generate()


static func create_shadow_texture() -> ImageTexture:
	var generator := ProceduralCloudTexture.new()
	generator.size = 256
	generator.scale = 4.0
	generator.octaves = 4
	generator.cloud_threshold = 0.3
	generator.cloud_softness = 0.4
	return generator.generate()