extends "res://scripts/creatures/creature.gd"
## The tutorial's wolf (docs/TUTORIAL_DESIGN.md §2, step "Wolves"): it comes
## out of the dark, circles at the edge of the light for a while, and slinks
## off. It never attacks. When it's gone, `gone` fires and the step ticks.

signal gone

const RING := 11.0
const CIRCLE_SECONDS := 18.0
const LEAVE_AFTER := 40.0        ## this far from you it's gone

var target: Node3D
var _a := 0.0
var _goal_d := 0.0
var _done := false

func begin(t: Node3D) -> void:
	target = t
	var away: Vector3 = global_position - t.global_position
	_a = atan2(away.z, away.x)
	state = "stalk"
	_state_t = CIRCLE_SECONDS

func display_name() -> String:
	return "Wolf"

func interact_prompt(_p: Node) -> String:
	return "Wolf (watching you from the dark)"

func _pick_target() -> Node3D:
	return target

func _think(dt: float) -> void:
	if target == null or not is_instance_valid(target):
		_leave()
		return
	_state_t -= dt
	var tp: Vector3 = target.global_position
	match state:
		"stalk":
			_a += dt * 0.35
			_go_to(tp + Vector3(cos(_a), 0, sin(_a)) * RING)
			if _state_t <= 0.0:
				state = "flee"
				_state_t = 15.0
		"flee":
			var away := global_position - tp
			away.y = 0.0
			steer(atan2(-away.x, -away.z))
			_goal_d = 99.0
			if global_position.distance_to(tp) > LEAVE_AFTER or _state_t <= 0.0:
				_leave()
		_:
			state = "stalk"

func _go_to(p: Vector3) -> void:
	var to := p - global_position
	to.y = 0.0
	if to.length() > 0.3:
		steer(atan2(-to.x, -to.z))
	_goal_d = to.length()

func _desired_speed() -> float:
	match state:
		"stalk": return 0.0 if _goal_d < 1.0 else (3.0 if _goal_d < 6.0 else 6.5)
		"flee": return 7.5
	return 0.0

func _leave() -> void:
	if _done:
		return
	_done = true
	gone.emit()
	queue_free()

## (A swipe makes it run.)
func _react(_from: Vector3) -> void:
	state = "flee"
	_state_t = 10.0