extends CharacterBody3D
## Kestrel EC-01 capsule — flight, cameras, enter/exit.
## Hull clips + plumes live on child "Kestrel" via kestrel_driver.gd.

@onready var interaction_area: Area3D = $InteractionArea
@onready var camera_pivot: Node3D = get_node_or_null("CameraPivot")
@onready var capsule_camera: Camera3D = get_node_or_null("CameraPivot/CapsuleCamera")
@onready var third_person_camera: Camera3D = $ThirdPersonCamera
@onready var interact_prompt: Label = get_node_or_null("/root/Node3D/HUD/InteractPrompt")
@onready var pause_menu: Control = get_node_or_null("/root/Node3D/HUD/PauseMenu")
@onready var body_collision: CollisionShape3D = get_node_or_null("CollisionShape3D")
@onready var flight_label: Label = get_node_or_null("/root/Node3D/HUD/FlightLabel")
@onready var kestrel: Node3D = get_node_or_null("Kestrel")

var player_inside: bool = false
var player_ref: CharacterBody3D = null
var using_third_person: bool = false
var f_was_down: bool = false

var mass: float = 6500.0
var thrust_force: float = 180000.0
var rotation_speed: float = 1.8
var surface_friction: float = 6.0

const MOON_RADIUS: float = 173700.0
const MOON_G: float = 1.62
const MOON_SOI: float = 400000.0
const EARTH_RADIUS: float = 637100.0
const EARTH_G: float = 9.81
const EARTH_SOI: float = 20000000.0
const CAM_FAR: float = 1000000.0
const NEAR_SURFACE_MARGIN: float = 300.0

var _moon_colliders: Array[CollisionObject3D] = []
var _crust_exception: bool = false

var free_look: bool = false
var look_sensitivity: float = 0.003
var orbit_yaw: float = 0.0
var orbit_pitch: float = 0.4
var orbit_distance: float = 14.0
var orbit_pitch_min: float = -1.2
var orbit_pitch_max: float = 1.2
var cockpit_yaw: float = 0.0
var cockpit_pitch: float = 0.0
var cockpit_look_limit_yaw: float = 1.45
var cockpit_look_limit_up: float = 1.0
var cockpit_look_limit_down: float = 0.55
var head_local: Transform3D = Transform3D.IDENTITY

var telem_body: String = "—"
var telem_alt: float = 0.0
var telem_speed: float = 0.0
var telem_vspeed: float = 0.0
var telem_hspeed: float = 0.0
var telem_vcirc: float = 0.0
var telem_dh: float = 0.0
var telem_earth_rng: float = 0.0
var telem_thrust: bool = false
var telem_has_alt: bool = false

var _gear_down: bool = true
var _hatch_crew_open: bool = false
var _hatch_dock_open: bool = false
var _ladder_out: bool = false
var _cabin_dim: bool = false
var _v_was: bool = false


func _ready() -> void:
	_ensure_actions()
	if interaction_area:
		interaction_area.monitoring = true
		interaction_area.monitorable = true
		interaction_area.body_entered.connect(_on_body_entered)
		interaction_area.body_exited.connect(_on_body_exited)
	if camera_pivot:
		camera_pivot.top_level = false
		head_local = camera_pivot.transform
	if capsule_camera:
		capsule_camera.near = 0.05
		capsule_camera.far = CAM_FAR
		capsule_camera.current = false
	if third_person_camera:
		third_person_camera.near = 0.1
		third_person_camera.far = CAM_FAR
		third_person_camera.current = false
	if flight_label:
		flight_label.visible = false
	_bind_kestrel()
	_collect_moon_colliders()
	call_deferred("_update_crust_exception")


func _bind_kestrel() -> void:
	if kestrel == null:
		kestrel = get_node_or_null("Kestrel")
	print("Kestrel hull=", kestrel, " driver=", kestrel.get_script() if kestrel else null)


func _hull() -> Node:
	return kestrel if kestrel else null


func _set_hull(prop: String, value: Variant) -> void:
	var h := _hull()
	if h and prop in h:
		h.set(prop, value)


func _moon() -> Node3D:
	return get_node_or_null("/root/Node3D/SolarSystem/Moon") as Node3D


func _earth() -> Node3D:
	return get_node_or_null("/root/Node3D/SolarSystem/Earth") as Node3D


func _habitat() -> Node3D:
	return get_node_or_null("/root/Node3D/SolarSystem/Moon/LovellAnchor/Station/Habitat") as Node3D


func _collect_moon_colliders() -> void:
	_moon_colliders.clear()
	var moon := _moon()
	if moon == null:
		return
	for n in moon.find_children("*", "PhysicsBody3D", true, false):
		if n == self:
			continue
		if str(n.name).begins_with("Shell"):
			continue
		if str(n.name).begins_with("Moon") and n is CollisionObject3D:
			_moon_colliders.append(n as CollisionObject3D)


func _inside_young() -> bool:
	var habitat := _habitat()
	if habitat == null:
		return false
	var lp: Vector3 = habitat.to_local(global_position)
	var radial: float = Vector2(lp.x, lp.z).length()
	return radial < 2000.0 and lp.y < 80.0 and lp.y > -120.0


func _update_crust_exception() -> void:
	var want: bool = _inside_young()
	if want == _crust_exception:
		return
	_crust_exception = want
	for body in _moon_colliders:
		if not is_instance_valid(body):
			continue
		if want:
			add_collision_exception_with(body)
		else:
			remove_collision_exception_with(body)


func _active_gravity() -> Dictionary:
	var moon := _moon()
	if moon:
		var d_m: float = global_position.distance_to(moon.global_position)
		if d_m >= 1.0 and d_m <= MOON_SOI:
			var to_c: Vector3 = moon.global_position - global_position
			return {
				"name": "Luna",
				"center": moon.global_position,
				"radius": MOON_RADIUS,
				"g": MOON_G,
				"accel": to_c.normalized() * MOON_G,
				"dist": d_m
			}
	var earth := _earth()
	if earth:
		var d_e: float = global_position.distance_to(earth.global_position)
		if d_e >= 1.0 and d_e <= EARTH_SOI:
			var to_c2: Vector3 = earth.global_position - global_position
			return {
				"name": "Earth",
				"center": earth.global_position,
				"radius": EARTH_RADIUS,
				"g": EARTH_G,
				"accel": to_c2.normalized() * EARTH_G,
				"dist": d_e
			}
	return {"name": "—", "center": Vector3.ZERO, "radius": 0.0, "g": 0.0, "accel": Vector3.ZERO, "dist": 0.0}


func _gravity_accel() -> Vector3:
	return _active_gravity()["accel"]


func _update_telemetry() -> void:
	telem_speed = velocity.length()
	telem_thrust = Input.is_key_pressed(KEY_SPACE)
	var earth := _earth()
	if earth:
		telem_earth_rng = maxf(0.0, global_position.distance_to(earth.global_position) - EARTH_RADIUS)
	else:
		telem_earth_rng = 0.0
	var body: Dictionary = _active_gravity()
	telem_body = str(body["name"])
	if telem_body == "—":
		telem_has_alt = false
		telem_alt = 0.0
		telem_vspeed = 0.0
		telem_hspeed = telem_speed
		telem_vcirc = 0.0
		telem_dh = 0.0
		return
	telem_has_alt = true
	var r: float = float(body["dist"])
	var rad: float = float(body["radius"])
	var g: float = float(body["g"])
	telem_alt = r - rad
	var radial: Vector3 = (global_position - body["center"]).normalized()
	telem_vspeed = velocity.dot(radial)
	telem_hspeed = (velocity - radial * telem_vspeed).length()
	telem_vcirc = sqrt(g * rad * rad / r) if r > 1.0 else 0.0
	telem_dh = telem_hspeed - telem_vcirc


func _update_flight_hud() -> void:
	if flight_label == null or not player_inside:
		return
	flight_label.visible = true
	var mode := "3P" if using_third_person else "1P"
	var thr := "THRUST" if telem_thrust else "IDLE"
	var vs_sign := "+" if telem_vspeed >= 0.0 else ""
	var alt_line: String
	var vcirc_line: String
	var dh_line: String
	if telem_has_alt:
		alt_line = "ALT   %8.0f m\n" % telem_alt
		vcirc_line = "VCIRC %8.1f m/s\n" % telem_vcirc
		var dh_sign := "+" if telem_dh >= 0.0 else ""
		dh_line = "ΔH    %s%7.1f m/s\n" % [dh_sign, telem_dh]
	else:
		alt_line = "ALT        —\n"
		vcirc_line = "VCIRC      —\n"
		dh_line = "ΔH         —\n"
	flight_label.text = (
		"[%s] %s | BODY %s\n" % [mode, thr, telem_body]
		+ alt_line
		+ "SPD   %8.1f m/s\n" % telem_speed
		+ "VS    %s%7.1f m/s\n" % [vs_sign, telem_vspeed]
		+ "H     %8.1f m/s\n" % telem_hspeed
		+ vcirc_line
		+ dh_line
		+ "EARTH %8.0f m" % telem_earth_rng
	)


func _clear_flight_hud() -> void:
	if flight_label:
		flight_label.visible = false
		flight_label.text = ""


func _on_body_entered(body: Node3D) -> void:
	if body.is_in_group("player"):
		player_ref = body
		if interact_prompt and not player_inside:
			interact_prompt.text = "Press F to Enter"
			interact_prompt.visible = true


func _on_body_exited(body: Node3D) -> void:
	if body.is_in_group("player") and not player_inside:
		player_ref = null
		if interact_prompt:
			interact_prompt.visible = false


func _unhandled_input(event: InputEvent) -> void:
	if not player_inside:
		return
	if event.is_action_pressed("ui_cancel"):
		if pause_menu and pause_menu.has_method("open_pause") and player_ref:
			pause_menu.open_pause(player_ref)
			get_viewport().set_input_as_handled()
		return
	if _event_toggles(event, "capsule_gear", KEY_G):
		_gear_down = not _gear_down
		_set_hull("gear_deploy", 1.0 if _gear_down else 0.0)
		get_viewport().set_input_as_handled()
	elif _event_toggles(event, "capsule_hatch_crew", KEY_H):
		_hatch_crew_open = not _hatch_crew_open
		_set_hull("hatch_crew_open", 1.0 if _hatch_crew_open else 0.0)
		get_viewport().set_input_as_handled()
	elif _event_toggles(event, "capsule_hatch_dock", KEY_J):
		_hatch_dock_open = not _hatch_dock_open
		_set_hull("hatch_dock_open", 1.0 if _hatch_dock_open else 0.0)
		get_viewport().set_input_as_handled()
	elif _event_toggles(event, "capsule_ladder", KEY_L):
		_ladder_out = not _ladder_out
		_set_hull("hatch_ladder_deploy", 1.0 if _ladder_out else 0.0)
		get_viewport().set_input_as_handled()
	elif _event_toggles(event, "capsule_instruments", KEY_I):
		_set_hull("instruments_demo", 1.0)
		get_viewport().set_input_as_handled()
	elif _event_toggles(event, "capsule_cabin_light", KEY_K):
		_cabin_dim = not _cabin_dim
		_set_hull("cabin_dim", _cabin_dim)
		get_viewport().set_input_as_handled()


func _ensure_actions() -> void:
	var binds := {
		"interact": KEY_F,
		"toggle_first_person": KEY_V,
		"capsule_gear": KEY_G,
		"capsule_hatch_crew": KEY_H,
		"capsule_hatch_dock": KEY_J,
		"capsule_ladder": KEY_L,
		"capsule_instruments": KEY_I,
		"capsule_cabin_light": KEY_K,
	}
	for action in binds.keys():
		if InputMap.has_action(action):
			continue
		InputMap.add_action(action)
		var ev := InputEventKey.new()
		ev.physical_keycode = binds[action]
		InputMap.action_add_event(action, ev)


func _event_toggles(event: InputEvent, action: String, key: Key) -> bool:
	if InputMap.has_action(action) and event.is_action_pressed(action):
		return true
	if event is InputEventKey and event.pressed and not event.echo and event.physical_keycode == key:
		return true
	return false


func _act_pressed(action: String) -> bool:
	return InputMap.has_action(action) and Input.is_action_pressed(action)


func _act_just(action: String) -> bool:
	return InputMap.has_action(action) and Input.is_action_just_pressed(action)


func _process(delta: float) -> void:
	var interact_now := _act_just("interact") or _just_key(KEY_F)
	if not player_inside and player_ref and interact_now:
		f_was_down = true
		enter_capsule()
		return
	if not player_inside:
		f_was_down = Input.is_physical_key_pressed(KEY_F)
		_update_crust_exception()
		return
	if interact_now and not f_was_down:
		f_was_down = true
		exit_capsule()
		return
	f_was_down = _act_pressed("interact") or Input.is_physical_key_pressed(KEY_F)
	if _act_just("toggle_first_person"):
		toggle_camera()
	elif not InputMap.has_action("toggle_first_person") and _just_key(KEY_V):
		toggle_camera()
	var was_free = free_look
	free_look = Input.is_mouse_button_pressed(MOUSE_BUTTON_RIGHT)
	if was_free and not free_look and not using_third_person:
		cockpit_yaw = 0.0
		cockpit_pitch = 0.0
	if Input.is_key_pressed(KEY_ALT):
		Input.mouse_mode = Input.MOUSE_MODE_VISIBLE
	else:
		Input.mouse_mode = Input.MOUSE_MODE_CAPTURED
	handle_flight(delta)
	_update_telemetry()
	_update_flight_hud()
	if using_third_person:
		update_third_person_camera()
		if third_person_camera and not third_person_camera.current:
			third_person_camera.make_current()
	else:
		update_cockpit_camera()
		if capsule_camera and not capsule_camera.current:
			capsule_camera.make_current()


func _just_key(key: Key) -> bool:
	var down := Input.is_physical_key_pressed(key)
	if key == KEY_V:
		var edge := down and not _v_was
		_v_was = down
		return edge
	return false


func _input(event: InputEvent) -> void:
	if not player_inside:
		return
	if Input.is_key_pressed(KEY_ALT):
		return
	if event is InputEventMouseMotion:
		if using_third_person:
			orbit_yaw -= event.relative.x * look_sensitivity
			orbit_pitch += event.relative.y * look_sensitivity
			orbit_pitch = clampf(orbit_pitch, orbit_pitch_min, orbit_pitch_max)
		elif free_look:
			cockpit_yaw -= event.relative.x * look_sensitivity
			cockpit_pitch -= event.relative.y * look_sensitivity
			cockpit_yaw = clamp(cockpit_yaw, -cockpit_look_limit_yaw, cockpit_look_limit_yaw)
			cockpit_pitch = clamp(cockpit_pitch, -cockpit_look_limit_down, cockpit_look_limit_up)


func enter_capsule() -> void:
	if player_inside or player_ref == null:
		return
	player_inside = true
	if interact_prompt:
		interact_prompt.visible = false
	player_ref.reparent(self)
	player_ref.position = Vector3(0, 0.5, 0)
	player_ref.rotation = Vector3.ZERO
	player_ref.set_physics_process(false)
	player_ref.set_process(true)
	player_ref.set_process_input(false)
	player_ref.set_process_unhandled_input(false)
	if player_ref.has_method("set_in_vehicle"):
		player_ref.set_in_vehicle(true)
	var player_col = player_ref.get_node_or_null("CollisionShape3D")
	if player_col:
		player_col.disabled = true
	var player_cam = player_ref.get_node_or_null("CameraPivot/Camera3D")
	if player_cam:
		player_cam.current = false
	player_ref.visible = false
	cockpit_yaw = 0.0
	cockpit_pitch = 0.0
	orbit_yaw = 0.0
	orbit_pitch = 0.4
	using_third_person = false
	f_was_down = true
	free_look = false
	if camera_pivot:
		camera_pivot.top_level = false
		camera_pivot.transform = head_local
	if third_person_camera:
		third_person_camera.current = false
	if capsule_camera:
		capsule_camera.near = 0.05
		capsule_camera.far = CAM_FAR
		capsule_camera.current = true
		capsule_camera.make_current()
	velocity = Vector3.ZERO
	FloatingOrigin.set_focus(self)
	Input.mouse_mode = Input.MOUSE_MODE_CAPTURED
	if flight_label:
		flight_label.visible = true
	_update_crust_exception()


func exit_capsule() -> void:
	if not player_inside or player_ref == null:
		return
	var exiting_player: CharacterBody3D = player_ref
	player_inside = false
	velocity = Vector3.ZERO
	free_look = false
	f_was_down = false
	using_third_person = false
	_set_hull("abort_burn", false)
	_set_hull("rcs_direction", 0)
	_clear_flight_hud()
	if body_collision:
		body_collision.disabled = false
	if is_instance_valid(camera_pivot):
		camera_pivot.top_level = false
		camera_pivot.transform = head_local
	if is_instance_valid(capsule_camera):
		capsule_camera.current = false
	if is_instance_valid(third_person_camera):
		third_person_camera.current = false
	var station := get_node_or_null("/root/Node3D/SolarSystem/Moon/LovellAnchor/Station")
	var dest: Node = station if station else get_tree().current_scene
	exiting_player.reparent(dest)
	exiting_player.global_position = global_position + global_transform.basis.y * 4.0
	var player_cam_pivot = exiting_player.get_node_or_null("CameraPivot")
	if player_cam_pivot:
		player_cam_pivot.rotation = Vector3.ZERO
	exiting_player.visible = true
	exiting_player.set_physics_process(true)
	exiting_player.set_process(true)
	exiting_player.set_process_input(true)
	exiting_player.set_process_unhandled_input(true)
	exiting_player.process_mode = Node.PROCESS_MODE_INHERIT
	var player_col = exiting_player.get_node_or_null("CollisionShape3D")
	if player_col:
		player_col.disabled = false
	if exiting_player.has_method("set_in_vehicle"):
		exiting_player.set_in_vehicle(false)
	var player_cam = exiting_player.get_node_or_null("CameraPivot/Camera3D")
	if player_cam:
		player_cam.current = true
		player_cam.make_current()
	if exiting_player.has_method("restore_from_vehicle"):
		exiting_player.restore_from_vehicle()
	FloatingOrigin.set_focus(exiting_player)
	Input.mouse_mode = Input.MOUSE_MODE_CAPTURED
	player_ref = null


func toggle_camera() -> void:
	using_third_person = not using_third_person
	if using_third_person:
		if capsule_camera:
			capsule_camera.current = false
		if third_person_camera:
			third_person_camera.near = 0.1
			third_person_camera.far = CAM_FAR
			third_person_camera.make_current()
	else:
		if third_person_camera:
			third_person_camera.current = false
		if camera_pivot:
			camera_pivot.top_level = false
			camera_pivot.transform = head_local
		if capsule_camera:
			capsule_camera.make_current()


func update_cockpit_camera() -> void:
	if not camera_pivot:
		return
	camera_pivot.top_level = false
	var b: Basis = head_local.basis
	b = b.rotated(b.x, cockpit_pitch)
	b = b.rotated(b.y, cockpit_yaw)
	b = b.orthonormalized()
	if abs(b.determinant()) < 0.5:
		camera_pivot.transform = head_local
		return
	camera_pivot.transform = Transform3D(b, head_local.origin)


func update_third_person_camera() -> void:
	if not third_person_camera:
		return
	var cy := cos(orbit_yaw)
	var sy := sin(orbit_yaw)
	var cp := cos(orbit_pitch)
	var sp := sin(orbit_pitch)
	var offset := Vector3(sy * cp, sp, cy * cp) * orbit_distance
	var local_off := Vector3(offset.x, -offset.z, offset.y)
	var cam_pos := global_position + global_transform.basis * local_off
	third_person_camera.global_position = cam_pos
	var target := global_position + global_transform.basis.y * 1.5
	var forward := target - cam_pos
	if forward.length_squared() < 0.0001:
		return
	forward = forward.normalized()
	var ref_up := global_transform.basis.z
	if abs(forward.dot(ref_up)) > 0.92:
		ref_up = global_transform.basis.x
	var right := ref_up.cross(forward)
	if right.length_squared() < 0.0001:
		return
	right = right.normalized()
	var up := forward.cross(right).normalized()
	var cam_basis := Basis(-right, up, -forward).orthonormalized()
	if abs(cam_basis.determinant()) < 0.5:
		return
	third_person_camera.global_basis = cam_basis


func handle_flight(delta: float) -> void:
	_update_crust_exception()
	var input_pitch := 0.0
	var input_roll := 0.0
	var input_yaw := 0.0
	if Input.is_key_pressed(KEY_W):
		input_pitch -= 1.0
	if Input.is_key_pressed(KEY_S):
		input_pitch += 1.0
	if Input.is_key_pressed(KEY_A):
		input_yaw += 1.0
	if Input.is_key_pressed(KEY_D):
		input_yaw -= 1.0
	if Input.is_key_pressed(KEY_Q):
		input_roll -= 1.0
	if Input.is_key_pressed(KEY_E):
		input_roll += 1.0
	rotate_object_local(Vector3.RIGHT, input_pitch * rotation_speed * delta)
	rotate_object_local(Vector3.FORWARD, -input_yaw * rotation_speed * delta)
	rotate_object_local(Vector3.UP, input_roll * rotation_speed * delta)
	var thrusting := Input.is_key_pressed(KEY_SPACE)
	_set_hull("abort_burn", thrusting)
	_set_hull("att_pitch", input_pitch)
	_set_hull("att_yaw", input_yaw)
	_set_hull("att_roll", input_roll)
	_set_hull("rcs_direction", 0)
	var acceleration: Vector3 = _gravity_accel()
	if thrusting:
		acceleration += global_transform.basis.y * (thrust_force / mass)
	velocity += acceleration * delta
	var near_surface := is_on_floor() or _crust_exception
	if not near_surface:
		var moon := _moon()
		if moon and global_position.distance_to(moon.global_position) < MOON_RADIUS + NEAR_SURFACE_MARGIN:
			near_surface = true
		var earth := _earth()
		if earth and global_position.distance_to(earth.global_position) < EARTH_RADIUS + NEAR_SURFACE_MARGIN:
			near_surface = true
	if near_surface:
		if body_collision:
			body_collision.disabled = false
		move_and_slide()
		if is_on_floor():
			velocity.x = move_toward(velocity.x, 0.0, surface_friction * delta)
			velocity.z = move_toward(velocity.z, 0.0, surface_friction * delta)
			if velocity.length() < 0.08:
				velocity = Vector3.ZERO
	else:
		if body_collision:
			body_collision.disabled = true
		global_position += velocity * delta
		PhysicsServer3D.body_set_state(
			get_rid(),
			PhysicsServer3D.BODY_STATE_TRANSFORM,
			global_transform
		)
		PhysicsServer3D.body_set_state(
			get_rid(),
			PhysicsServer3D.BODY_STATE_LINEAR_VELOCITY,
			velocity
		)