extends SceneTree

## Dev tool: build a PlayerHUD against a stand-in player, let it lay out, and
## print where every element actually landed.
##
##     godot --headless --path . -s res://debug/hud_layout_check.gd
##
## A HUD element that lands at (0, 0) with zero size is the single most common
## thing to get wrong here, and it is invisible in a headless smoke test and
## easy to miss in a screenshot. This prints the rects so the answer is a number.

var _frames := 0
var _hud: PlayerHUD


func _initialize() -> void:
	var stand_in := CharacterBody3D.new()
	stand_in.name = "StandInPlayer"
	root.add_child(stand_in)

	_hud = PlayerHUD.new()
	_hud.player = stand_in
	root.add_child(_hud)


func _process(_delta: float) -> bool:
	_frames += 1

	# A hidden Control keeps its last rect and contributes nothing to its
	# container's minimum size, so measuring the ammo card while the stand-in
	# player holds no weapon reads a stale position from a collapsed column and
	# reports a layout bug that is not there. Force the states that matter to be
	# visible, then give the containers a frame to re-sort before measuring.
	if _frames == 4:
		# Freeze the HUD first. Its own `_process` hides the ammo card whenever
		# the player holds no weapon, so anything forced visible here is undone
		# again before the measurement and what gets read is the stale rect of a
		# hidden control inside a collapsed column.
		_hud.set_process(false)
		_hud._ammo_card.visible = true
		_hud._ammo_num.text = "30"
		_hud._ammo_max.text = "/ 30"
		_hud._weapon_name.text = "DOUBLE BARREL SHOTGUN"
		_hud._chain_row.visible = true
		for pip in _hud._grenade_row.get_children():
			(pip as Control).visible = true
	if _frames < 8:
		return false

	print("viewport = ", root.get_visible_rect().size)
	if OS.has_environment("HUD_TREE"):
		_dump(_hud, 0)
	var fails := 0
	for node in _hud.find_children("*", "Control", true, false):
		var c := node as Control
		# Only the elements that are supposed to occupy space. Containers that
		# legitimately shrink to their content are not interesting.
		if c.name in ["Crosshair", "ReloadRing", "DeathScreen"]:
			var r := c.get_global_rect()  # GLOBAL: get_rect() is parent-relative and lies about where a nested element really sits
			print("  %-12s pos=%s size=%s" % [c.name, r.position, r.size])
			if r.size.x < 100.0 or r.size.y < 100.0:
				print("    FAIL: expected to fill the viewport")
				fails += 1

	# The ammo card, which must hug the RIGHT edge inside its margin. It sat
	# flush against the left instead, because a VBoxContainer hands each child
	# its own horizontal placement and the alignment flag was on the column.
	var vr := root.get_visible_rect().size
	var card := _find_by_class("PanelContainer")
	if card == null:
		print("  MISSING ammo card")
		fails += 1
	else:
		var r := card.get_global_rect()
		var right_gap := vr.x - (r.position.x + r.size.x)
		print("  %-12s pos=%s size=%s right_gap=%.0f"
			% ["ammo", r.position, r.size, right_gap])
		if r.size.x < 60.0:
			print("    FAIL: collapsed to nothing")
			fails += 1
		elif right_gap < 0.0:
			print("    FAIL: runs off the right edge of the screen")
			fails += 1
		elif right_gap > 120.0:
			print("    FAIL: not anchored to the right edge (gap %.0f)" % right_gap)
			fails += 1

	print("HUD LAYOUT: %s" % ("PASS" if fails == 0 else "FAIL (%d)" % fails))
	quit(1 if fails > 0 else 0)
	return true


## The whole Control tree with GLOBAL rects. `HUD_TREE=1` to switch on — when a
## container collapses, the answer is always visible in its parent chain and
## never in the leaf you noticed the problem on.
func _dump(node: Node, depth: int) -> void:
	for child in node.get_children():
		if child is Control:
			var c := child as Control
			var r := c.get_global_rect()
			print("%s%s [%s] pos=%s size=%s vis=%s"
				% ["  ".repeat(depth + 1), c.name, c.get_class(),
					r.position, r.size, c.visible])
		_dump(child, depth + 1)


func _find_by_class(cls: String) -> Control:
	for n in _hud.find_children("*", cls, true, false):
		return n as Control
	return null