extends SceneTree

# Drives the players apart at a set speed and measures actual droop: how much
# longer the rope's real path is than the straight line between the anchors.
# droop ~0 means visually taut. That is the thing the fix has to deliver.

var rope
var p1
var p2
var t := 0.0
var speed := 0.0
var trial := 0
var speeds := [1.0, 3.0, 6.0]
var worst_droop_while_taut := 0.0
var saw_taut := false


func _initialize() -> void:
	var level = load("res://scenes/game_scene/levels/3dlevel.tscn").instantiate()
	root.add_child(level)
	rope = level.get_node("Path3DRope")
	p1 = level.get_node("Player1")
	p2 = level.get_node("Player2")
	rope.can_snap = false
	speed = speeds[0]
	print("max_length=%.1f reel_speed=%.1f taut_margin=%.2f" % [
		rope.max_length, rope.reel_speed, rope.taut_margin])


# Length of the rope's actual polyline through every segment.
func path_len() -> float:
	var total := 0.0
	var pts := []
	for s in rope.segments:
		var h: float = s.get_child(0).shape.height * 0.5
		pts.append(s.position + s.transform.basis.y * h)
	var last = rope.segments[-1]
	var lh: float = last.get_child(0).shape.height * 0.5
	pts.append(last.position - last.transform.basis.y * lh)
	for i in range(pts.size() - 1):
		total += pts[i].distance_to(pts[i + 1])
	return total


func _physics_process(d: float) -> bool:
	t += d
	if t < 0.4:
		return false
	# Walk them apart at a controlled rate.
	p1.global_position.x -= speed * d * 0.5
	p2.global_position.x += speed * d * 0.5
	p1.velocity.x = 0.0
	p2.velocity.x = 0.0

	var gap: float = p1.global_position.distance_to(p2.global_position)
	var droop: float = path_len() - gap
	if rope.taut:
		saw_taut = true
		worst_droop_while_taut = max(worst_droop_while_taut, droop)

	if fmod(t, 0.6) < d:
		print("  sep=%.0fm/s gap=%5.2f rope=%5.2f path=%5.2f droop=%5.2f taut=%s" % [
			speed, gap, rope._rope_length, path_len(), droop, str(rope.taut)])

	if gap > rope.max_length * 1.3:
		print("trial sep=%.0fm/s -> saw_taut=%s worst droop while taut=%.3f\n" % [
			speed, str(saw_taut), worst_droop_while_taut])
		trial += 1
		if trial >= speeds.size():
			quit(0)
			return true
		speed = speeds[trial]
		saw_taut = false
		worst_droop_while_taut = 0.0
		p1.global_position.x = -1.0
		p2.global_position.x = 1.0
		t = 0.0
	return false