class_name CockpitPracticalLighting
extends Node3D

const DiveAlertLevel = preload("res://game/domain/dive/dive_alert_level.gd")
const CockpitMaterialPalette = preload(
	"res://game/presentation/cockpit/cockpit_material_palette.gd"
)
const CockpitMeshFactory = preload(
	"res://game/presentation/cockpit/cockpit_mesh_factory.gd"
)

const CockpitPressureBulkhead = preload(
	"res://game/presentation/cockpit/cockpit_pressure_bulkhead.gd"
)

const CAGE_LAMP_SCENE = preload("res://game/presentation/cockpit/assets/models/cage_lamp.glb")

## Flange centre of the right-hand lamp, on the flat end cap of the pressure
## hull beside the porthole (the left lamp mirrors x). The cap is flat there, so
## the lamp is seated square to it, facing the cabin.
const LAMP_MOUNT_OFFSET := Vector3(0.636, 1.106, -1.3)
## Centre of the glass globe in the lamp model: where the light is emitted.
const LAMP_GLOBE_CENTRE := Vector3(0.0, 0.0, 0.064)
## Globe emission (1.5 as exported): lower, so the globe does not bloom into a blob.
const LAMP_GLASS_ENERGY := 1.0
## Tungsten-like caged lamps: the cabin's main light.
const WARM_LAMP_COLOR := Color(1.0, 0.66, 0.4)
const WARM_LAMP_ENERGY := 0.5
## Same dimming ratio as before when the red emergency light takes over.
const WARM_LAMP_CRITICAL_ENERGY := 0.23
## Short range and a steep falloff: each lamp makes a pool on the wall around
## it and leaves the lower and outer hull dark.
const WARM_LAMP_RANGE_M := 1.6
const WARM_LAMP_ATTENUATION := 2.0
## Cabin parts are centimetre-scale: the default bias detaches their shadows.
const WARM_LAMP_SHADOW_BIAS := 0.03

var _materials: CockpitMaterialPalette
var _warm_lights: Array[OmniLight3D] = []
var _emergency_light: OmniLight3D
var _porthole_fill: OmniLight3D


func _init(materials: CockpitMaterialPalette) -> void:
	_materials = materials
	name = "PracticalLighting"
	_add_caged_lamp(-1.0)
	_add_caged_lamp(1.0)
	_add_fill_light()
	_add_emergency_light()


func present(alert_level: DiveAlertLevel.Value) -> void:
	_emergency_light.visible = alert_level >= DiveAlertLevel.Value.CRITICAL
	for light: OmniLight3D in _warm_lights:
		light.light_energy = (
			WARM_LAMP_CRITICAL_ENERGY
			if alert_level >= DiveAlertLevel.Value.CRITICAL
			else WARM_LAMP_ENERGY
		)


func practical_light_count() -> int:
	return _warm_lights.size()


func _add_caged_lamp(side: float) -> void:
	var root := Node3D.new()
	root.name = "CagedLamp"
	root.position = Vector3(
		side * LAMP_MOUNT_OFFSET.x,
		LAMP_MOUNT_OFFSET.y,
		LAMP_MOUNT_OFFSET.z
	)
	add_child(root)
	var model := CAGE_LAMP_SCENE.instantiate() as Node3D
	model.name = "CageLampModel"
	root.add_child(model)
	# The light sits inside the cage, 3 cm from its bars: casting, the lamp's
	# own body would swallow it.
	CockpitMeshFactory.disable_shadow_casting(model)
	var glass := CockpitMeshFactory.own_surface_material(
		model.find_child("CageLamp_Glass", true, false) as MeshInstance3D
	)
	if glass != null:
		glass.emission_energy_multiplier = LAMP_GLASS_ENERGY
	var light := OmniLight3D.new()
	light.name = "WarmPracticalLight"
	light.position = LAMP_GLOBE_CENTRE
	light.light_color = WARM_LAMP_COLOR
	light.light_energy = WARM_LAMP_ENERGY
	light.omni_range = WARM_LAMP_RANGE_M
	light.omni_attenuation = WARM_LAMP_ATTENUATION
	light.shadow_enabled = true
	light.shadow_bias = WARM_LAMP_SHADOW_BIAS
	root.add_child(light)
	_warm_lights.append(light)


func _add_fill_light() -> void:
	# The only cool light in the cabin: sea light entering through the porthole,
	# placed just inside the glass so it rims the ring, its bolts and the first
	# band of wall, and reaches the dashboard only from behind.
	var porthole_fill := OmniLight3D.new()
	porthole_fill.name = "PortholeFill"
	porthole_fill.position = Vector3(0.0, 0.47, -1.2)
	porthole_fill.light_color = Color(0.30, 0.56, 0.78)
	porthole_fill.light_energy = 1.0
	porthole_fill.omni_range = 1.1
	porthole_fill.shadow_enabled = false
	# 30 cm behind the glass, it would mirror itself as a hard blue point.
	porthole_fill.light_cull_mask &= ~CockpitPressureBulkhead.PORTHOLE_GLASS_RENDER_LAYER_BIT
	add_child(porthole_fill)
	_porthole_fill = porthole_fill


func fill_light_ignores_porthole_glass() -> bool:
	return (
		_porthole_fill != null
		and (
			_porthole_fill.light_cull_mask
			& CockpitPressureBulkhead.PORTHOLE_GLASS_RENDER_LAYER_BIT
		) == 0
	)


func _add_emergency_light() -> void:
	_emergency_light = OmniLight3D.new()
	_emergency_light.name = "EmergencyLight"
	# High and central, so no single dial sits right under it and washes out.
	_emergency_light.position = Vector3(0.0, 1.1, -0.95)
	_emergency_light.light_color = Color(1.0, 0.04, 0.015)
	_emergency_light.light_energy = 1.4
	_emergency_light.omni_range = 2.4
	_emergency_light.visible = false
	add_child(_emergency_light)