extends SceneTree

## Spawn-overlap audit. Every site, every pair of dynamic bodies: do their colliders
## interpenetrate on frame one?
##
## The spawn guard clamps an exploding prop and names it, but only if Jolt happens to
## resolve that pair violently on the frames it's watching — a symmetric overlap can sit
## quietly for a whole run and then launch a filing cabinet the day you change something
## unrelated. This finds them by measurement instead of by luck.
##
##   Godot --headless --path game --script dev/probe_overlap.gd

const CLEAR := 0.004        ## metres of slop allowed before we call it an overlap

func _initialize() -> void:
	var main: Node = (load("res://main.tscn") as PackedScene).instantiate()
	get_root().add_child(main)
	await process_frame
	var bad := 0
	for id in Levels.ORDER:
		main._load_level(id)
		await process_frame
		bad += _audit(id)
	print("\n%s" % ("CLEAN — nothing interpenetrates at spawn" if bad == 0
		else "%d overlapping pairs" % bad))
	quit()

## Godot renames duplicates to @RigidBody3D@NNN, which is useless in a report. The GLB
## instance under the body still knows what it is.
func _label(b: Node) -> String:
	for c in b.get_children():
		if c is Node3D and not (c is CollisionShape3D):
			return String(c.name).to_lower()
	return String(b.name)

func _audit(id: String) -> int:
	var boxes: Array = []
	for n in get_nodes_in_group("smashable"):
		var b := n as RigidBody3D
		if b == null or b.freeze:
			continue
		for c in b.get_children():
			var col := c as CollisionShape3D
			if col == null:
				continue
			var half := Vector3.ZERO
			if col.shape is BoxShape3D:
				half = (col.shape as BoxShape3D).size * 0.5
			elif col.shape is SphereShape3D:
				# a sphere's AABB over-reports at the corners, so nested round produce
				# would false-positive; shrink it to the inscribed cube
				var r: float = (col.shape as SphereShape3D).radius * 0.577
				half = Vector3(r, r, r)
			else:
				continue
			boxes.append({"node": b, "name": _label(b),
				"c": b.global_position + col.position, "h": half})
	var hits: Array = []
	for i in boxes.size():
		for j in range(i + 1, boxes.size()):
			var a: Dictionary = boxes[i]
			var b2: Dictionary = boxes[j]
			var d: Vector3 = (a["c"] as Vector3) - (b2["c"] as Vector3)
			var need: Vector3 = (a["h"] as Vector3) + (b2["h"] as Vector3)
			# AABB test: they only overlap if they overlap on ALL THREE axes
			var pen := Vector3(need.x - absf(d.x), need.y - absf(d.y), need.z - absf(d.z))
			if pen.x > CLEAR and pen.y > CLEAR and pen.z > CLEAR:
				hits.append({"an": a["name"], "bn": b2["name"],
					"pen": minf(pen.x, minf(pen.y, pen.z)), "at": a["c"]})
	hits.sort_custom(func(x, y): return float(x["pen"]) > float(y["pen"]))
	print("\n=== %-11s %d dynamic boxes, %d overlapping pairs" % [id, boxes.size(), hits.size()])
	for k in mini(8, hits.size()):
		var h: Dictionary = hits[k]
		print("    %.3f m into  %-18s / %-18s  at %s" % [h["pen"],
			h["an"], h["bn"], h["at"]])
	return hits.size()