class_name CockpitMaterialPalette
extends RefCounted

const NAVAL_STEEL_TEXTURE_PATH := (
	"res://game/presentation/cockpit/assets/naval_painted_steel_albedo.png"
)
const GAUGE_FACE_TEXTURE_PATH := (
	"res://game/presentation/cockpit/assets/analog_gauge_face_albedo.png"
)

var painted_steel: Material
var dark_steel: Material
var overhead_steel: StandardMaterial3D
var brushed_steel: StandardMaterial3D
var brass: Material
var copper: Material
var rubber: Material
var gauge_face: StandardMaterial3D
var gauge_glass: StandardMaterial3D
var needle_paint: StandardMaterial3D
var instrument_screen: ShaderMaterial
var warm_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
	)
	overhead_steel = _textured_material(
		_load_texture(NAVAL_STEEL_TEXTURE_PATH),
		Color(0.64, 0.69, 0.68),
		0.64,
		0.56,
		Vector3(1.6, 1.6, 1.6)
	)
	brushed_steel = _plain_material(Color(0.27, 0.30, 0.29), 0.82, 0.30)
	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)
	gauge_face = _textured_material(
		_load_texture(GAUGE_FACE_TEXTURE_PATH),
		Color(0.78, 0.74, 0.64),
		0.02,
		0.72
	)
	gauge_glass = _glass_material()
	needle_paint = _plain_material(Color(0.68, 0.055, 0.022), 0.12, 0.44)
	instrument_screen = _screen_material()
	warm_emission = _emissive_material(Color(0.96, 0.52, 0.18), 2.4)


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 _textured_material(
	texture: Texture2D,
	tint: Color,
	metallic: float,
	roughness: float,
	uv_scale: Vector3 = Vector3.ONE
) -> StandardMaterial3D:
	var material := StandardMaterial3D.new()
	material.albedo_color = tint
	material.albedo_texture = texture
	material.metallic = metallic
	material.roughness = roughness
	material.uv1_scale = uv_scale
	material.texture_filter = BaseMaterial3D.TEXTURE_FILTER_LINEAR_WITH_MIPMAPS_ANISOTROPIC
	return material


func _load_texture(resource_path: String) -> ImageTexture:
	var image := Image.load_from_file(resource_path)
	if image == null or image.is_empty():
		push_error("Unable to load cockpit texture: %s" % resource_path)
		return null
	return ImageTexture.create_from_image(image)


func _glass_material() -> StandardMaterial3D:
	var material := StandardMaterial3D.new()
	material.transparency = BaseMaterial3D.TRANSPARENCY_ALPHA
	material.albedo_color = Color(0.42, 0.68, 0.66, 0.13)
	material.metallic = 0.12
	material.roughness = 0.08
	material.cull_mode = BaseMaterial3D.CULL_DISABLED
	return material


func _screen_material() -> ShaderMaterial:
	var shader := Shader.new()
	shader.code = """
shader_type spatial;
render_mode diffuse_burley, specular_schlick_ggx;

void fragment() {
	vec2 centered = UV - vec2(0.5);
	float vignette = 1.0 - smoothstep(0.28, 0.72, length(centered));
	float scanline = 0.94 + 0.06 * sin(UV.y * 720.0);
	float edge = mix(0.68, 1.0, vignette);
	vec3 phosphor = vec3(0.025, 0.105, 0.11) * edge * scanline;
	ALBEDO = phosphor;
	EMISSION = phosphor * 0.38;
	METALLIC = 0.08;
	ROUGHNESS = 0.18;
	SPECULAR = 0.82;
}
"""
	var material := ShaderMaterial.new()
	material.shader = shader
	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