extends CanvasLayer
## Local-only trauma pivot: never modifies the player's aim angles.
const SHAKE_SECONDS := 0.42
const BLOOD_SECONDS := 1.15
const SPLAT_COUNT := 7
var pivot: Node3D
var shake_left := 0.0
var blood_left := 0.0
var intensity := 0.0
var phase := 0.0
var active := true
var overlay: Control
var vignette: ColorRect
var shader_material: ShaderMaterial
var splats: Array[TextureRect] = []

func _ready() -> void:
	layer = 2
	overlay = Control.new()
	overlay.mouse_filter = Control.MOUSE_FILTER_IGNORE
	add_child(overlay)
	overlay.set_anchors_and_offsets_preset(Control.PRESET_FULL_RECT)
	vignette = ColorRect.new()
	vignette.mouse_filter = Control.MOUSE_FILTER_IGNORE
	shader_material = ShaderMaterial.new()
	shader_material.shader = load("res://assets/effects/damage_vignette.gdshader")
	vignette.material = shader_material
	overlay.add_child(vignette)
	vignette.set_anchors_and_offsets_preset(Control.PRESET_FULL_RECT)
	for i in SPLAT_COUNT:
		var splat := TextureRect.new()
		splat.texture = load("res://assets/effects/blood.png")
		splat.expand_mode = TextureRect.EXPAND_IGNORE_SIZE
		splat.stretch_mode = TextureRect.STRETCH_KEEP_ASPECT_CENTERED
		splat.mouse_filter = Control.MOUSE_FILTER_IGNORE
		splat.modulate.a = 0
		overlay.add_child(splat)
		splats.append(splat)

func hit(amount: float) -> void:
	if not active or amount <= 0:
		return
	# Refresh instead of stacking tweens/particles: bounded cost and shake.
	intensity = minf(1.0, maxf(intensity, 0.55 + amount / 100.0) + 0.12)
	shake_left = SHAKE_SECONDS
	blood_left = BLOOD_SECONDS
	phase = randf_range(0, TAU)
	var viewport_size := get_viewport().get_visible_rect().size
	for i in splats.size():
		var splat := splats[i]
		var size := minf(viewport_size.x, viewport_size.y) * randf_range(0.22, 0.38)
		splat.size = Vector2.ONE * size
		splat.pivot_offset = splat.size * 0.5
		# Keep the central reticle and HUD readable; splats lie near the edges.
		var center := Vector2.ZERO
		match i % 4:
			0: center = viewport_size * Vector2(randf_range(0.06, 0.17), randf_range(0.25, 0.90))
			1: center = viewport_size * Vector2(randf_range(0.83, 0.95), randf_range(0.25, 0.90))
			2: center = viewport_size * Vector2(randf_range(0.25, 0.75), randf_range(0.82, 0.98))
			3: center = viewport_size * Vector2(randf_range(0.3, 0.8), randf_range(0.04, 0.13))
		splat.position = center - splat.size * 0.5
		splat.rotation = randf_range(-PI, PI)
		splat.modulate = Color(0.85, 0.1, 0.12, 0.85 * intensity)
	shader_material.set_shader_parameter("strength", intensity)

func _process(delta: float) -> void:
	if not active:
		return
	phase += delta * 42.0
	shake_left = maxf(0, shake_left - delta)
	blood_left = maxf(0, blood_left - delta)
	var shake := pow(shake_left / SHAKE_SECONDS, 2.0) * intensity
	if is_instance_valid(pivot):
		pivot.position = Vector3(sin(phase) * 0.025, cos(phase * 1.3) * 0.018, sin(phase * 0.8) * 0.012) * shake
		pivot.rotation = Vector3(sin(phase * 0.9) * 0.024, cos(phase) * 0.013, sin(phase * 1.1) * 0.035) * shake
	var alpha := blood_left / BLOOD_SECONDS
	for splat in splats:
		splat.modulate.a = alpha * 0.85 * intensity
	shader_material.set_shader_parameter("strength", minf(1, alpha * 1.4) * intensity)
	if blood_left <= 0:
		intensity = 0

func stop() -> void:
	active = false
	shake_left = 0
	blood_left = 0
	intensity = 0
	if is_instance_valid(pivot):
		pivot.transform = Transform3D.IDENTITY
	overlay.hide()