class_name NpcAvatar
extends CharacterBody3D
## Visual + navigation wrapper around a logic NPCController (ADR-0001).
## Gives the controller a body, color-coded by archetype, and simple movement.

const NPCController := preload("res://src/core/npc_controller.gd")
const Rules := preload("res://src/core/rules.gd")
const Materials := preload("res://src/game/materials.gd")

var npc: NPCController = null
var spawn_position: Vector3 = Vector3.ZERO
var target_position: Vector3 = Vector3.ZERO
var door_position: Vector3 = Vector3(0, 0.5, 1.2)
var awaiting_interaction := false
var arrived := false
## Seconds idle at an arrived waypoint. Ordinary traffic lives for a while, then
## despawns so the entrance does not fill with standers (TODO: NPC crowd cap).
var idle_s := 0.0
var lifetime_s := 90.0
var ephemeral := true
## Crowd presentation (PLAN: Public Crowd Reaction). "watch" rubbernecks at the
## incident, "flee" clears away from it, "" is normal navigation.
var reaction_mode := ""
var reaction_point := Vector3.ZERO
var _reaction_timer := 0.0
const RUBBERNECK_S := 12.0
const FLEE_S := 20.0
const FLEE_SPEED := 2.4
var agent: NavigationAgent3D = null
## Set once the nav agent proves it has a path; direct movement is the fallback.
var _nav_usable := false
var _nav_try_frames := 0

const TYPE_COLORS := {
	Rules.NpcType.TOURIST: Color(0.90, 0.75, 0.55),
	Rules.NpcType.PERFORMER: Color(0.80, 0.55, 0.90),
	Rules.NpcType.INFLUENCER: Color(0.95, 0.55, 0.55),
	Rules.NpcType.CONFUSED_VISITOR: Color(0.95, 0.85, 0.50),
	Rules.NpcType.INTOXICATED: Color(0.60, 0.75, 0.50),
	Rules.NpcType.TRESPASSER: Color(0.55, 0.55, 0.75),
	Rules.NpcType.VIOLENT_THREAT: Color(0.85, 0.25, 0.25),
	Rules.NpcType.MENTAL_CRISIS: Color(0.85, 0.65, 0.45),
	Rules.NpcType.AUTHORIZED_STAFF: Color(0.45, 0.70, 0.90),
	Rules.NpcType.AUTHORIZED_GUEST: Color(0.60, 0.85, 0.65),
	Rules.NpcType.DELIVERY: Color(0.80, 0.70, 0.40),
	Rules.NpcType.RESPONDER: Color(0.25, 0.30, 0.85),
	Rules.NpcType.PROTESTER: Color(0.90, 0.40, 0.20),
}

func _init() -> void:
	npc = NPCController.new()

func get_npc_controller() -> NPCController:
	return npc

func setup(profile: NpcProfile, intent: String, seed_value: int, p_spawn: Vector3, p_target: Vector3, p_door: Vector3 = Vector3(0, 0.5, 1.2), p_npc_id: String = "", p_override: Dictionary = {}) -> void:
	var id := p_npc_id if p_npc_id != "" else "npc_%d" % seed_value
	npc.setup(id, profile, intent, seed_value)
	npc.access_override = p_override
	_visual_seed = seed_value
	spawn_position = p_spawn
	target_position = p_target
	door_position = p_door
	position = p_spawn
	npc.fsm.state_changed.connect(_on_state_changed)
	add_to_group("npc")
	_build_body(profile.npc_type)
	_nav_usable = false
	_nav_try_frames = 0
	agent = NavigationAgent3D.new()
	agent.name = "NavAgent"
	agent.path_desired_distance = 0.4
	agent.target_desired_distance = 4.0
	agent.radius = 0.35
	agent.height = 1.2
	add_child(agent)

	# Normalize intent targets: approach the entrance, stop near the door.
	var collider := CollisionShape3D.new()
	var shape := CapsuleShape3D.new()
	shape.radius = 0.35
	var height_scale: float = _rig.scale.y if _rig else 1.0
	shape.height = 1.6 * height_scale
	collider.shape = shape
	collider.position = Vector3(0, 0.8 * height_scale, 0)
	add_child(collider)

var _visual_seed := 0
var _rig: Node3D = null
var _head: Node3D = null
var _bob_phase := 0.0
var _guard_ref: Node3D = null
var _focus_circle: MeshInstance3D = null
var _name_tag: Label3D = null
## Theater props and limbs for the idle poses (ADR-0010 rig).
var _photo_prop: MeshInstance3D = null
var _sign_prop: MeshInstance3D = null
var _legs: Array[MeshInstance3D] = []
var _arms: Array[MeshInstance3D] = []
var _theater_t := 0.0
var _photo_prop_base_y := 0.0
var _sign_prop_base_y := 0.0
const SKIN_TONE := Color(0.88, 0.72, 0.60)
const PANTS_COLOR := Color(0.22, 0.22, 0.26)
const HAIR_COLORS := [Color(0.12, 0.1, 0.08), Color(0.35, 0.22, 0.12), Color(0.55, 0.42, 0.28), Color(0.15, 0.15, 0.18)]

## Which small accessory a role wears. This is look-only: the player must still
## read intent from behaviour, never from the archetype name (ADR-0010).
const ACCESSORIES := {
	Rules.NpcType.AUTHORIZED_STAFF: "cap",
	Rules.NpcType.RESPONDER: "cap",
	Rules.NpcType.DELIVERY: "cap",
	Rules.NpcType.TOURIST: "backpack",
	Rules.NpcType.INFLUENCER: "sunglasses",
	Rules.NpcType.TRESPASSER: "hood",
	Rules.NpcType.VIOLENT_THREAT: "hood",
	Rules.NpcType.MENTAL_CRISIS: "hood",
	Rules.NpcType.AUTHORIZED_GUEST: "lanyard",
	Rules.NpcType.PERFORMER: "none",
	Rules.NpcType.PROTESTER: "none",
	Rules.NpcType.INTOXICATED: "none",
	Rules.NpcType.CONFUSED_VISITOR: "none",
}

## Clothing palette for one avatar. Pure and seed-driven so crowds read as
## individuals and the result is deterministic (tests rely on that).
static func outfit_for(npc_type: int, seed_value: int) -> Dictionary:
	var base: Color = TYPE_COLORS.get(npc_type, Color(0.7, 0.7, 0.7))
	var frac := float((seed_value * 1103515245 + 12345) % 1000) / 1000.0
	var shirt := base.lerp(Color(0.92, 0.92, 0.94), frac * 0.22)
	shirt = shirt.darkened(frac * 0.12)
	# Jeans through khaki/chino, so not every avatar wears the same trousers.
	var pants := Color(0.16, 0.18, 0.23).lerp(Color(0.46, 0.38, 0.28), frac)
	var hair_index := (seed_value * 7) % HAIR_COLORS.size()
	return {
		"shirt": shirt,
		"sleeves": shirt.darkened(0.16),
		"pants": pants,
		"hair": HAIR_COLORS[hair_index],
		"skin": SKIN_TONE.darkened(frac * 0.18),
		"accessory": ACCESSORIES.get(npc_type, "none"),
		"height_scale": 0.92 + 0.16 * frac,
		"blend": frac,
	}

func _build_body(npc_type: int) -> void:
	_rig = Node3D.new()
	_rig.name = "Rig"
	add_child(_rig)
	var outfit := outfit_for(npc_type, _visual_seed)
	var shirt: Color = outfit["shirt"]
	var sleeves: Color = outfit["sleeves"]
	var pants: Color = outfit["pants"]
	var skin: Color = outfit["skin"]
	var hair: Color = outfit["hair"]
	_rig.scale.y = float(outfit["height_scale"])
	var limbs_color := sleeves
	# Torso, with a shoulder block and hips so the silhouette is not a tube.
	_add_capsule(_rig, 0.30, 0.90, Vector3(0, 1.02, 0), shirt, 0.0, "cloth")
	_add_box_mesh(_rig, Vector3(0.58, 0.14, 0.28), Vector3(0, 1.36, 0), shirt, "cloth")
	_add_box_mesh(_rig, Vector3(0.44, 0.18, 0.26), Vector3(0, 0.62, 0), pants, "cloth")
	# Legs and arms are tracked so the walk cycle can swing them.
	_legs.append(_add_capsule(_rig, 0.12, 0.8, Vector3(-0.16, 0.4, 0), pants, 0.0, "cloth"))
	_legs.append(_add_capsule(_rig, 0.12, 0.8, Vector3(0.16, 0.4, 0), pants, 0.0, "cloth"))
	_arms.append(_add_capsule(_rig, 0.09, 0.7, Vector3(-0.42, 1.28, 0), limbs_color, 8.0, "cloth"))
	_arms.append(_add_capsule(_rig, 0.09, 0.7, Vector3(0.42, 1.28, 0), limbs_color, -8.0, "cloth"))
	# Hands and shoes give the limbs an end point at conversation distance.
	_add_sphere(_rig, 0.065, Vector3(-0.47, 0.94, 0.03), skin, "skin")
	_add_sphere(_rig, 0.065, Vector3(0.47, 0.94, 0.03), skin, "skin")
	# Neck, head, face, hair, shoes so the body reads as a person (ADR-0010).
	_add_capsule(_rig, 0.08, 0.16, Vector3(0, 1.48, 0), skin, 0.0, "skin")
	_head = Node3D.new()
	_head.name = "Head"
	_head.position = Vector3(0, 1.62, 0)
	_add_sphere(_head, 0.17, Vector3.ZERO, skin, "skin")
	_add_sphere(_head, 0.18, Vector3(0, 0.08, -0.02), hair, "cloth")
	_add_sphere(_head, 0.035, Vector3(-0.06, 0.02, 0.14), Color(0.08, 0.08, 0.1), "glass")
	_add_sphere(_head, 0.035, Vector3(0.06, 0.02, 0.14), Color(0.08, 0.08, 0.1), "glass")
	_rig.add_child(_head)
	_add_box_mesh(_rig, Vector3(0.16, 0.08, 0.28), Vector3(-0.16, 0.05, 0.02), Color(0.12, 0.12, 0.14), "rubber")
	_add_box_mesh(_rig, Vector3(0.16, 0.08, 0.28), Vector3(0.16, 0.05, 0.02), Color(0.12, 0.12, 0.14), "rubber")
	_add_accessory(str(outfit["accessory"]), shirt)
	_build_focus_circle()
	_add_props(npc_type)

## Small role accessory: cap, hood, backpack, sunglasses or a staff lanyard.
func _add_accessory(kind: String, shirt: Color) -> void:
	match kind:
		"cap":
			_add_sphere(_head, 0.175, Vector3(0, 0.12, 0), shirt.darkened(0.15), "cloth")
			_add_box_mesh(_head, Vector3(0.30, 0.03, 0.16), Vector3(0, 0.10, 0.16), shirt.darkened(0.22), "cloth")
		"hood":
			_add_sphere(_head, 0.205, Vector3(0, 0.03, -0.03), Color(0.16, 0.16, 0.18), "cloth")
		"backpack":
			_add_box_mesh(_rig, Vector3(0.34, 0.42, 0.16), Vector3(0, 1.06, -0.24), Color(0.24, 0.28, 0.36), "cloth")
			_add_box_mesh(_rig, Vector3(0.30, 0.06, 0.02), Vector3(0, 1.24, -0.33), Color(0.42, 0.44, 0.5), "cloth")
		"sunglasses":
			_add_box_mesh(_head, Vector3(0.24, 0.05, 0.03), Vector3(0, 0.04, 0.15), Color(0.06, 0.06, 0.08), "glass")
		"lanyard":
			_add_box_mesh(_rig, Vector3(0.05, 0.06, 0.02), Vector3(0, 1.20, 0.16), Color(0.85, 0.78, 0.30), "painted_metal")
			_add_box_mesh(_rig, Vector3(0.02, 0.20, 0.02), Vector3(-0.08, 1.34, 0.14), Color(0.3, 0.32, 0.36), "cloth")
			_add_box_mesh(_rig, Vector3(0.02, 0.20, 0.02), Vector3(0.08, 1.34, 0.14), Color(0.3, 0.32, 0.36), "cloth")
		_:
			pass

func _build_focus_circle() -> void:
	_focus_circle = MeshInstance3D.new()
	_focus_circle.name = "FocusCircle"
	# Blue, semi-transparent disc floating in front of the face (ADR-0008).
	# Billboarded so it always reads as a circle on screen.
	var disc := CylinderMesh.new()
	disc.top_radius = 0.15
	disc.bottom_radius = 0.15
	disc.height = 0.001
	disc.radial_segments = 24
	_focus_circle.mesh = disc
	var mat := StandardMaterial3D.new()
	mat.shading_mode = BaseMaterial3D.SHADING_MODE_UNSHADED
	mat.albedo_color = Color(0.25, 0.55, 1.0, 0.45)
	mat.transparency = BaseMaterial3D.TRANSPARENCY_ALPHA
	mat.billboard_mode = BaseMaterial3D.BILLBOARD_ENABLED
	_focus_circle.material_override = mat
	_focus_circle.position = Vector3(0, 0, 0.30)
	_focus_circle.visible = false
	_head.add_child(_focus_circle)
	_name_tag = Label3D.new()
	_name_tag.name = "NameTag"
	_name_tag.text = npc.profile.display_name if npc and npc.profile else ""
	_name_tag.font_size = 48
	_name_tag.pixel_size = 0.004
	_name_tag.billboard = BaseMaterial3D.BILLBOARD_ENABLED
	_name_tag.position = Vector3(0, 0.58, 0)
	_name_tag.modulate = Color(0.95, 0.95, 0.9, 0.9)
	_name_tag.visible = false
	_head.add_child(_name_tag)

func set_focus_visual(focused: bool, menu_open: bool = false) -> void:
	if _focus_circle:
		_focus_circle.visible = focused
		var mat := _focus_circle.material_override as StandardMaterial3D
		if mat:
			mat.albedo_color = Color(0.35, 0.65, 1.0, 0.7) if menu_open else Color(0.25, 0.55, 1.0, 0.45)
		_focus_circle.scale = Vector3.ONE * (1.15 if menu_open else 1.0)
	if _name_tag:
		_name_tag.visible = focused

func _add_capsule(parent: Node3D, radius: float, height: float, pos: Vector3,
		color: Color, z_rot: float = 0.0, role: String = "cloth") -> MeshInstance3D:
	var mi := MeshInstance3D.new()
	var mesh := CapsuleMesh.new()
	mesh.radius = radius
	mesh.height = height
	mi.mesh = mesh
	mi.position = pos
	mi.rotation_degrees.z = z_rot
	mi.material_override = _material(color, role)
	parent.add_child(mi)
	return mi

func _add_sphere(parent: Node3D, radius: float, pos: Vector3, color: Color,
		role: String = "skin") -> void:
	var mi := MeshInstance3D.new()
	var mesh := SphereMesh.new()
	mesh.radius = radius
	mesh.height = radius * 2.0
	mi.mesh = mesh
	mi.position = pos
	mi.material_override = _material(color, role)
	parent.add_child(mi)

func _add_box_mesh(parent: Node3D, size: Vector3, pos: Vector3, color: Color,
		role: String = "cloth") -> MeshInstance3D:
	var mi := MeshInstance3D.new()
	var mesh := BoxMesh.new()
	mesh.size = size
	mi.mesh = mesh
	mi.position = pos
	mi.material_override = _material(color, role)
	parent.add_child(mi)
	return mi

func _material(color: Color, role: String = "cloth") -> StandardMaterial3D:
	return Materials.flat(color, role)

## Small per-archetype props so silhouettes differ (camera, box, hat, sign…).
func _add_props(npc_type: int) -> void:
	var chest_y := 1.25
	match npc_type:
		Rules.NpcType.INFLUENCER:
			_photo_prop = _add_box_prop(_rig, Vector3(0.16, 0.1, 0.09), Vector3(0.3, chest_y, 0.22), Color(0.1, 0.1, 0.1))
			_photo_prop_base_y = _photo_prop.position.y
			_add_box_prop(_rig, Vector3(0.05, 0.05, 0.06), Vector3(0.34, chest_y + 0.06, 0.30), Color(0.4, 0.7, 1.0))
		Rules.NpcType.DELIVERY:
			_add_box_prop(_rig, Vector3(0.34, 0.26, 0.28), Vector3(0.0, 1.02, 0.3), Color(0.55, 0.4, 0.25))
		Rules.NpcType.PERFORMER:
			var hat := _material(Color(0.85, 0.2, 0.25))
			var cone := MeshInstance3D.new()
			var cm := CylinderMesh.new()
			cm.top_radius = 0.02
			cm.bottom_radius = 0.22
			cm.height = 0.4
			cone.mesh = cm
			cone.material_override = hat
			cone.position = Vector3(0, 0.26, 0)
			_head.add_child(cone)
			# Hat in one hand and a small board in the other: the performer plays
			# to the sidewalk once at the waypoint.
			_add_box_prop(_rig, Vector3(0.06, 0.5, 0.06), Vector3(-0.42, 1.3, 0.14), Color(0.45, 0.35, 0.25))
			_sign_prop = _add_box_prop(_rig, Vector3(0.42, 0.32, 0.03), Vector3(-0.46, 1.6, 0.14), Color(0.95, 0.9, 0.75))
			_sign_prop_base_y = _sign_prop.position.y
		Rules.NpcType.PROTESTER:
			_add_box_prop(_rig, Vector3(0.05, 1.2, 0.05), Vector3(0.28, 1.45, 0.18), Color(0.4, 0.36, 0.32))
			_sign_prop = _add_box_prop(_rig, Vector3(0.5, 0.42, 0.04), Vector3(0.48, 1.55, 0.18), Color(0.93, 0.93, 0.95))
			_sign_prop_base_y = _sign_prop.position.y
		Rules.NpcType.TOURIST:
			_photo_prop = _add_box_prop(_rig, Vector3(0.3, 0.36, 0.14), Vector3(-0.34, 1.15, -0.18), Color(0.25, 0.3, 0.45))
			_photo_prop_base_y = _photo_prop.position.y
		Rules.NpcType.CONFUSED_VISITOR:
			_add_box_prop(_rig, Vector3(0.3, 0.05, 0.34), Vector3(0, 0.92, 0.06), Color(0.9, 0.88, 0.8))

func _add_box_prop(parent: Node3D, size: Vector3, pos: Vector3, color: Color) -> MeshInstance3D:
	var mi := MeshInstance3D.new()
	var mesh := BoxMesh.new()
	mesh.size = size
	mi.mesh = mesh
	mi.position = pos
	mi.material_override = _material(color)
	parent.add_child(mi)
	return mi

## Rubberneck: idle people stop and turn toward the incident. Returns false when
## this NPC is too engaged (walking, being talked to, already leaving) to watch.
func start_rubberneck(at: Vector3) -> bool:
	if not arrived or npc.leave_requested or leave_requested_by_lifetime:
		return false
	# Someone actually waiting at the entrance is being dealt with, not a bystander.
	# Avatars live under the identity SceneRoot, so `position` matches world space
	# and also works before the node enters the tree (tests).
	if awaiting_interaction and (position - door_position).length() < 3.0:
		return false
	if reaction_mode == "flee":
		return false
	reaction_mode = "watch"
	reaction_point = at
	_reaction_timer = RUBBERNECK_S
	velocity = Vector3.ZERO
	return true

## Panic: clear away from the incident (usually the door) in a straight line.
func start_flee(from: Vector3) -> void:
	if npc.leave_requested or leave_requested_by_lifetime:
		return
	reaction_mode = "flee"
	reaction_point = from
	_reaction_timer = FLEE_S
	var away := global_position - from
	away.y = 0.0
	if away.length() < 0.5:
		away = Vector3(0.0, 0.0, 1.0)
	target_position = global_position + away.normalized() * 25.0
	target_position.y = 0.5
	arrived = false
	awaiting_interaction = false

func reaction_is_active() -> bool:
	return reaction_mode != ""

func _tick_reaction(delta: float) -> void:
	if reaction_mode == "":
		return
	_reaction_timer -= delta
	if reaction_mode == "flee":
		if _reaction_timer <= 0.0 or (global_position - target_position).length() < 1.5:
			reaction_mode = ""
			queue_free()
		return
	if _reaction_timer <= 0.0:
		reaction_mode = ""

## Turn the body toward the reaction point without moving.
func _face_reaction_point(delta: float) -> void:
	var to_point := reaction_point - global_position
	to_point.y = 0.0
	if to_point.length() < 0.1:
		return
	var target_yaw := atan2(-to_point.x, -to_point.z)
	rotation.y = lerp_angle(rotation.y, target_yaw, clampf(delta * 4.0, 0.0, 1.0))

func _physics_process(delta: float) -> void:
	if npc == null or npc.fsm == null:
		return
	_advance_fsm(delta)
	_tick_reaction(delta)
	if reaction_mode == "watch":
		velocity = Vector3.ZERO
		_face_reaction_point(delta)
		_animate(delta)
		return
	if reaction_mode == "flee":
		_move_toward_target(delta)
		_animate(delta)
		return
	_move_toward_target(delta)
	_animate(delta)

## Procedural walk bob + head-toward-guard cue when the NPC is aware.
## Theater pose for the current intent once the NPC has stopped walking.
## "sit" at the steps, "photo" for camera props, "perform" for the hat/sign,
## "film" for a slow pan, otherwise "idle".
func theater_pose() -> String:
	if not arrived:
		return "idle"
	match npc.intent:
		"sit":
			return "sit"
		"photo":
			return "photo"
		"film":
			return "film"
		"perform":
			return "perform"
		_:
			return "idle"

## How far the rig drops for a seated pose. Pure so it is headless-testable.
static func crouch_for_pose(pose: String) -> float:
	return -0.34 if pose == "sit" else 0.0

## Vertical lift of a held camera prop. `phase` is seconds; the raise is brief so
## it reads as taking a photo rather than a permanently raised arm.
static func prop_lift_for_pose(pose: String, phase: float) -> float:
	if pose != "photo" and pose != "film":
		return 0.0
	return maxf(0.0, sin(phase * 1.7)) * 0.16

## Opposite arm/leg swing for the walk cycle. `side` is 0 or 1; pure so the gait
## can be checked without a scene tree.
static func limb_swing(phase: float, side: int, amplitude: float) -> float:
	return sin(phase + float(side) * PI) * amplitude

## Sway amount for a performer playing to the sidewalk.
static func sway_for_pose(pose: String, phase: float) -> float:
	if pose != "perform":
		return 0.0
	return sin(phase * 2.2) * 0.09

func _animate(delta: float) -> void:
	if _rig == null:
		return
	var speed := Vector2(velocity.x, velocity.z).length()
	var pose := theater_pose()
	var crouch := crouch_for_pose(pose)
	if speed > 0.3:
		_bob_phase += delta * (6.0 + speed)
		_rig.position.y = sin(_bob_phase) * 0.035
		_rig.rotation.x = sin(_bob_phase * 0.5) * 0.04
		for i in _legs.size():
			_legs[i].rotation.x = limb_swing(_bob_phase, i, 0.5)
		for i in _arms.size():
			_arms[i].rotation.x = limb_swing(_bob_phase, i, -0.38)
	elif pose != "idle" or not is_zero_approx(_rig.position.y):
		# Idle theater: seated, photographing, filming, or performing.
		_theater_t += delta
		_bob_phase = 0.0
		_rig.position.y = lerpf(_rig.position.y, crouch, 0.12)
		_rig.rotation.x = lerpf(_rig.rotation.x, 0.0, 0.2)
		var lift := prop_lift_for_pose(pose, _theater_t)
		if _photo_prop:
			_photo_prop.position.y = _photo_prop_base_y + lift
			_photo_prop.rotation.x = -lift * 1.4
		var sway := sway_for_pose(pose, _theater_t)
		if _sign_prop:
			_sign_prop.rotation.z = sway
			_sign_prop.position.y = _sign_prop_base_y + absf(sway) * 0.25
		if _legs.size() == 2:
			# Negative pitch swings the legs forward (toward the way the body faces).
			var leg_angle := deg_to_rad(-78.0) if pose == "sit" else 0.0
			_legs[0].rotation.x = lerpf(_legs[0].rotation.x, leg_angle, 0.12)
			_legs[1].rotation.x = lerpf(_legs[1].rotation.x, leg_angle, 0.12)
		for arm in _arms:
			arm.rotation.x = lerpf(arm.rotation.x, 0.0, 0.14)
	else:
		_bob_phase = 0.0
		_rig.position.y = lerpf(_rig.position.y, 0.0, 0.2)
		_rig.rotation.x = lerpf(_rig.rotation.x, 0.0, 0.2)
		for i in _legs.size():
			_legs[i].rotation.x = lerpf(_legs[i].rotation.x, 0.0, 0.2)
		for arm in _arms:
			arm.rotation.x = lerpf(arm.rotation.x, 0.0, 0.2)
	# The focus circle billboards via its material; no per-frame look_at needed.
	# Attention cue: head turns toward the guard when awareness was raised.
	if _head != null and npc.guard_noticed:
		if _guard_ref == null or not is_instance_valid(_guard_ref):
			_guard_ref = get_tree().get_first_node_in_group("guard") as Node3D
		if _guard_ref:
			var to_guard := (_guard_ref.global_position - global_position)
			to_guard.y = 0.0
			var world_yaw := atan2(to_guard.x, to_guard.z)
			var fwd := -_rig.global_transform.basis.z
			var parent_yaw := atan2(fwd.x, fwd.z)
			_head.rotation.y = lerp_angle(_head.rotation.y, world_yaw - parent_yaw, 0.1)

func _advance_fsm(delta: float) -> void:
	# Routine traffic despawns after a while once it has finished its walk, so
	# the crowd cap is not permanently occupied by idle standers.
	if ephemeral and arrived and npc.fsm.current_state != "LEAVING":
		idle_s += delta
		if idle_s >= lifetime_s:
			leave_requested_by_lifetime = true
			return
	# Returning-trespasser: an NPC directed away may circle back to the door.
	if npc.tick_return(delta):
		arrived = false
		awaiting_interaction = false
		target_position = door_position
		return
	if npc.leave_requested or leave_requested_by_lifetime:
		var away := global_position + (global_position - spawn_position).normalized() * 40.0
		away.y = 0.5
		target_position = away
		if (global_position - away).length() < 2.0:
			queue_free()
		return
	if arrived and not awaiting_interaction:
		awaiting_interaction = true

var leave_requested_by_lifetime := false

func _move_toward_target(delta: float) -> void:
	if agent == null:
		_move_direct(delta)
		return
	# Re-assigning the target every physics frame invalidates the path, so
	# get_next_path_position() keeps returning the current position and the
	# avatar never moves. Only update the agent when the target changes.
	if agent.target_position != target_position:
		agent.target_position = target_position
	if agent.is_navigation_finished():
		if (global_position - target_position).length() < 3.0:
			_arrive()
		else:
			# Path finished but we are far away: navigation is unusable, fall back.
			_move_direct(delta)
		return
	# Learn whether the navmesh actually serves this spot.
	if not _nav_usable:
		_nav_try_frames += 1
		if agent.is_target_reachable():
			_nav_usable = true
		elif _nav_try_frames > 10:
			_move_direct(delta)
			return
	var next := agent.get_next_path_position()
	# Godot reports the current position as the first path point (on the navmesh
	# plane, so below the body) and only advances past it once the agent is within
	# path_desired_distance. Steering at the point we are standing on gives a
	# zero-length direction, and steering at any point merely "far enough" away can
	# pick the old start behind us. Follow the first path point that is genuinely
	# closer to the destination than we are.
	var path := agent.get_current_navigation_path()
	if path.size() >= 2:
		var goal: Vector3 = path[path.size() - 1]
		var here_to_goal := Vector2(goal.x - global_position.x, goal.z - global_position.z).length()
		for i in range(1, path.size()):
			var candidate: Vector3 = path[i]
			candidate.y = global_position.y
			var candidate_to_goal := Vector2(goal.x - candidate.x, goal.z - candidate.z).length()
			if candidate_to_goal < here_to_goal - 0.05:
				next = candidate
				break
	var dir := (next - global_position)
	dir.y = 0.0
	if dir.length() < 0.2:
		velocity = Vector3.ZERO
		return
	dir = dir.normalized()
	var speed := FLEE_SPEED if reaction_mode == "flee" else 1.3
	velocity.x = dir.x * speed
	velocity.z = dir.z * speed
	velocity.y -= 9.8 * delta
	look_at(global_position + Vector3(dir.x, 0, dir.z), Vector3.UP)
	move_and_slide()

## Fallback used when no navigation mesh is available (e.g. minimal scenes).
func _move_direct(delta: float) -> void:
	var to_target := target_position - global_position
	to_target.y = 0.0
	var dist := to_target.length()
	if dist < 0.7:
		_arrive()
		return
	var dir := to_target.normalized()
	var speed := FLEE_SPEED if reaction_mode == "flee" else 1.3
	velocity.x = dir.x * speed
	velocity.z = dir.z * speed
	velocity.y -= 9.8 * delta
	look_at(global_position + Vector3(dir.x, 0, dir.z), Vector3.UP)
	move_and_slide()

func _arrive() -> void:
	arrived = true
	velocity = Vector3.ZERO
	if npc.intent == "enter" or npc.intent == "trespass" or npc.intent == "deliver" or npc.intent == "arrive":
		target_position = door_position
		if (global_position - door_position).length() < 0.8:
			awaiting_interaction = true

func _on_state_changed(_node: Object, _from: String, to_state: String) -> void:
	match to_state:
		"LEAVING":
			npc.leave_requested = true
		"THREATENING", "FORCING_ENTRY":
			# Advance toward the door posture; keep it simple for the prototype.
			pass