class_name CockpitMaterialPalette
extends RefCounted

var painted_steel: Material
var dark_steel: Material
var brass: Material
var copper: Material
var rubber: Material
var ivory: Material
var warm_emission: StandardMaterial3D
var red_emission: StandardMaterial3D


func _init() -> void:
	painted_steel = _weathered_material(
		Color(0.045, 0.12, 0.125),
		Color(0.16, 0.18, 0.17),
		0.52,
		0.58,
		0.13
	)
	dark_steel = _weathered_material(
		Color(0.045, 0.055, 0.055),
		Color(0.22, 0.24, 0.22),
		0.78,
		0.44,
		0.08
	)
	brass = _weathered_material(
		Color(0.28, 0.18, 0.045),
		Color(0.08, 0.16, 0.13),
		0.74,
		0.38,
		0.17
	)
	copper = _weathered_material(
		Color(0.34, 0.12, 0.045),
		Color(0.055, 0.18, 0.15),
		0.72,
		0.42,
		0.12
	)
	rubber = _plain_material(Color(0.012, 0.018, 0.018), 0.0, 0.92)
	ivory = _plain_material(Color(0.72, 0.69, 0.56), 0.05, 0.63)
	warm_emission = _emissive_material(Color(0.96, 0.52, 0.18), 2.4)
	red_emission = _emissive_material(Color(0.92, 0.055, 0.025), 3.6)


func _weathered_material(
	base_color: Color,
	worn_color: Color,
	metallic: float,
	roughness: float,
	wear_amount: float
) -> ShaderMaterial:
	var shader := Shader.new()
	shader.code = """
shader_type spatial;
render_mode diffuse_burley, specular_schlick_ggx;

uniform vec4 base_color : source_color;
uniform vec4 worn_color : source_color;
uniform float metallic_value : hint_range(0.0, 1.0);
uniform float roughness_value : hint_range(0.0, 1.0);
uniform float wear_amount : hint_range(0.0, 0.4);

float hash21(vec2 p) {
	return fract(sin(dot(p, vec2(127.1, 311.7))) * 43758.5453123);
}

float value_noise(vec2 p) {
	vec2 cell = floor(p);
	vec2 local = fract(p);
	local = local * local * (3.0 - 2.0 * local);
	float a = hash21(cell);
	float b = hash21(cell + vec2(1.0, 0.0));
	float c = hash21(cell + vec2(0.0, 1.0));
	float d = hash21(cell + vec2(1.0, 1.0));
	return mix(mix(a, b, local.x), mix(c, d, local.x), local.y);
}

void fragment() {
	float broad = value_noise(UV * 11.0);
	float grain = value_noise(UV * 73.0 + vec2(4.2, 8.7));
	float wear = smoothstep(0.76, 1.0, broad) * wear_amount;
	ALBEDO = mix(base_color.rgb * mix(0.78, 1.08, broad), worn_color.rgb, wear);
	METALLIC = metallic_value;
	ROUGHNESS = clamp(roughness_value + (grain - 0.5) * 0.22, 0.16, 0.96);
}
"""
	var material := ShaderMaterial.new()
	material.shader = shader
	material.set_shader_parameter("base_color", base_color)
	material.set_shader_parameter("worn_color", worn_color)
	material.set_shader_parameter("metallic_value", metallic)
	material.set_shader_parameter("roughness_value", roughness)
	material.set_shader_parameter("wear_amount", wear_amount)
	return material


func _plain_material(
	color: Color,
	metallic: float,
	roughness: float
) -> StandardMaterial3D:
	var material := StandardMaterial3D.new()
	material.albedo_color = color
	material.metallic = metallic
	material.roughness = roughness
	return material


func _emissive_material(color: Color, energy: float) -> StandardMaterial3D:
	var material := StandardMaterial3D.new()
	material.shading_mode = BaseMaterial3D.SHADING_MODE_UNSHADED
	material.albedo_color = color
	material.emission_enabled = true
	material.emission = color
	material.emission_energy_multiplier = energy
	return material