@tool
extends DirectionalLight3D
class_name DayNightController

signal time_changed(current_hours: float)

@export var grid_manager_path: NodePath
@export_range(1.0, 48.0, 0.5) var day_length_hours: float = 12.0
@export_range(1.0, 600.0, 1.0) var real_seconds_per_game_hour: float = 60.0
@export_range(0.0, 48.0, 0.25) var start_time_of_day_hours: float = 6.0
@export var orbit_axis: Vector3 = Vector3(1.0, 0.0, -1.0)
@export_range(0.0, 90.0, 0.5) var inclination_degrees: float = 35.0

var _grid_manager: Node3D = null
var _time_of_day_hours: float = 0.0
var _initial_environment_settings: Dictionary = {}
var _sunlight_multiplier: float = 1.0

func _ready() -> void:
	set_process(true)
	_resolve_references()
	_time_of_day_hours = clamp(start_time_of_day_hours, 0.0, day_length_hours)
	_apply_sun_lighting()
	_emit_time_changed()
	_capture_initial_environment()
	_update_environment()

func _process(delta: float) -> void:
	if Engine.is_editor_hint():
		return
	if day_length_hours <= 0.0 or real_seconds_per_game_hour <= 0.0:
		return
	_time_of_day_hours = fposmod(_time_of_day_hours + delta / real_seconds_per_game_hour, day_length_hours)
	_apply_sun_lighting()
	_emit_time_changed()
	_update_environment()

func _resolve_references() -> void:
	if grid_manager_path != NodePath():
		_grid_manager = get_node_or_null(grid_manager_path)
	else:
		_grid_manager = get_parent() as Node3D

func _apply_sun_lighting() -> void:
	if day_length_hours <= 0.0:
		return
	var cycle: float = 0.0
	if day_length_hours > 0.0:
		cycle = fposmod(_time_of_day_hours / day_length_hours, 1.0)
	var sun_angle: float = cycle * TAU
	var axis: Vector3 = orbit_axis.normalized()
	if axis.length() == 0.0:
		axis = Vector3.RIGHT
	var direction: Vector3 = Vector3.UP.rotated(axis, sun_angle)
	direction = direction.rotated(Vector3.UP, deg_to_rad(inclination_degrees)).normalized()
	var target: Vector3 = _grid_manager.global_transform.origin if _grid_manager else global_transform.origin
	var sun_distance: float = 60.0
	var sun_position: Vector3 = target - direction * sun_distance
	var up_vector: Vector3 = Vector3.UP
	if direction.is_equal_approx(up_vector) or direction.is_equal_approx(-up_vector):
		up_vector = Vector3.FORWARD
	look_at_from_position(sun_position, target, up_vector)
	var daylight_phase: float = sin((sun_angle - TAU * 0.25))
	var daylight: float = clamp(daylight_phase * 0.5 + 0.5, 0.0, 1.0)
	var dawn_color: Color = Color(0.95, 0.58, 0.32)
	var night_color: Color = Color(0.12, 0.18, 0.35)
	var day_color: Color = Color(1.0, 0.96, 0.88)
	var warm_mix: Color = dawn_color.lerp(day_color, clamp((daylight - 0.25) / 0.5, 0.0, 1.0))
	light_color = night_color.lerp(warm_mix, daylight)
	light_energy = lerp(0.05, 1.25, daylight)
	shadow_enabled = daylight > 0.1
	_sunlight_multiplier = daylight

func get_time_of_day_hours() -> float:
	return _time_of_day_hours

func get_day_length_hours() -> float:
	return day_length_hours

func _emit_time_changed() -> void:
	emit_signal("time_changed", _time_of_day_hours)

func _capture_initial_environment() -> void:
	var world: World3D = get_world_3d()
	if not world:
		return
	var env: Environment = world.environment
	if env:
		_initial_environment_settings = {
			"ambient_light_color": env.ambient_light_color,
			"ambient_light_energy": env.ambient_light_energy,
			"background_color": env.background_color
		}

func _update_environment() -> void:
	var world: World3D = get_world_3d()
	if not world:
		return
	var env: Environment = world.environment
	if not env:
		return
	var daylight: float = clamp(_sunlight_multiplier, 0.0, 1.0)
	var ambient_day: Color = Color(0.6, 0.7, 0.85)
	var ambient_night: Color = Color(0.02, 0.05, 0.1)
	var background_day: Color = Color(0.5, 0.75, 1.0)
	var background_night: Color = Color(0.01, 0.02, 0.08)
	env.ambient_light_color = ambient_night.lerp(ambient_day, daylight)
	env.ambient_light_energy = lerp(0.15, 1.5, daylight)
	env.background_color = background_night.lerp(background_day, daylight)