extends Node
class_name Dust

## LEVEL 0's mechanic: you cannot see what you are here to destroy.
##
## Every smashable in the Backrooms is invisible but SOLID — you find things by walking
## into them. Discharging the fire extinguisher throws a cloud of powder; anything it
## touches is coated and shows for a few seconds before the coating settles and the
## object goes back to being nothing.
##
## And you breathe it. Every cloud puts a little in your lungs, and the haze that builds
## is on YOUR side of the glass — it whites out the room. So the mechanic argues with
## itself: spray more to see individual objects, and see the room less. The intended
## rhythm is spray → switch to something heavy → break it before the coating settles →
## spray again, coughing.
##
## Enough dust in you and you cough: the camera jolts, the screen blooms, and it feeds
## Rage, because of course it does.
##
## Godot 4.7 GDScript 2.0.

const CLOUD_RANGE := 9.5            ## how far the powder carries
const CLOUD_ANGLE := 0.80           ## half-angle of the cone, radians
const CLOUD_ENVELOPE := 2.6         ## everything this close is coated regardless of aim
const COAT_TIME := 7.0              ## seconds an object stays visible
const INHALE_PER_PUFF := 0.085
const DECAY := 0.021                ## dust per second your lungs clear
const COUGH_AT := 0.72
const PUFF_COOLDOWN := 0.55

var rage: Rage
var active := false                 ## only true on a site whose spec says invisible

var inhaled := 0.0                  ## 0..1
var _cd := 0.0
var _cough_cd := 0.0
var _cam: Camera3D
var _player: Node3D
var _hidden: Array = []             ## every smashable we've hidden on this site

var _haze: ColorRect
var _cough_snd: AudioStreamPlayer
var _puff_snd: AudioStreamPlayer

const HAZE_SHADER := """
shader_type canvas_item;
uniform float dust : hint_range(0.0, 1.0) = 0.0;
uniform float bloom : hint_range(0.0, 1.0) = 0.0;
void fragment() {
	// flat lift plus a heavier wash at the edges: powder in the air, and powder on you
	vec2 d = (UV - vec2(0.5)) * vec2(1.0, 0.62);
	float r = length(d) * 2.0;
	float edge = smoothstep(0.25, 1.25, r);
	float a = dust * (0.16 + 0.38 * edge) + bloom * 0.45;
	COLOR = vec4(0.93, 0.91, 0.80, clamp(a, 0.0, 0.92));
}
"""

func setup(player: Node3D, cam: Camera3D, r: Rage, hud_layer: CanvasLayer) -> void:
	_player = player
	_cam = cam
	rage = r

	_haze = ColorRect.new()
	_haze.set_anchors_preset(Control.PRESET_FULL_RECT)
	_haze.mouse_filter = Control.MOUSE_FILTER_IGNORE
	var sh := Shader.new()
	sh.code = HAZE_SHADER
	var m := ShaderMaterial.new()
	m.shader = sh
	_haze.material = m
	hud_layer.add_child(_haze)

	_puff_snd = AudioStreamPlayer.new()
	_puff_snd.stream = _make_noise(0.55, 900.0, 3.0)
	_puff_snd.volume_db = -8.0
	add_child(_puff_snd)
	_cough_snd = AudioStreamPlayer.new()
	_cough_snd.stream = _make_noise(0.42, 190.0, 11.0)
	_cough_snd.volume_db = -4.0
	add_child(_cough_snd)

# ---------------------------------------------------------------- site setup
## Called after a level is populated. On an `invisible` site every smashable is hidden;
## anywhere else this clears itself out so the mechanic can't leak between levels.
func adopt(tree: SceneTree, invisible: bool) -> void:
	for e in _hidden:
		if is_instance_valid(e):
			_show(e as Smashable, true)
	_hidden.clear()
	inhaled = 0.0
	active = invisible
	if not invisible:
		return
	for n in tree.get_nodes_in_group("smashable"):
		var s := n as Smashable
		if s == null:
			continue
		_hidden.append(s)
		# _coat writes surface overrides; a mesh with no override slots silently ignores
		# them, so seed each surface with a copy of its own material up front
		_seed_overrides(s)
		_show(s, false)

## _coat writes surface OVERRIDES, and a surface with no override slot silently ignores
## them — so seed every surface up front with a copy of whatever material it actually
## resolves to. Imported GLBs put materials in either place, hence the two-step lookup.
func _seed_overrides(s: Smashable) -> void:
	for mi in Floorplan.meshes(s):
		var m := mi as MeshInstance3D
		if m.mesh == null:
			continue
		for i in m.mesh.get_surface_count():
			var src := _surface_material(m, i)
			if src != null:
				m.set_surface_override_material(i, src.duplicate())

static func _surface_material(m: MeshInstance3D, i: int) -> Material:
	var over := m.get_surface_override_material(i)
	if over != null:
		return over
	if m.mesh == null:
		return null
	return m.mesh.surface_get_material(i)

func _show(s: Smashable, visible: bool) -> void:
	if not is_instance_valid(s):
		return
	for mi in Floorplan.meshes(s):
		(mi as MeshInstance3D).visible = visible

# ---------------------------------------------------------------- the cloud
## Fired by Player on right-click while the extinguisher is out. Returns true if it went.
func discharge() -> bool:
	if not active or _cd > 0.0 or _cam == null:
		return false
	_cd = PUFF_COOLDOWN
	inhaled = clampf(inhaled + INHALE_PER_PUFF, 0.0, 1.0)
	_puff_snd.pitch_scale = randf_range(0.94, 1.08)
	_puff_snd.play()
	_spawn_puff()

	var origin := _cam.global_position
	var dir := -_cam.global_transform.basis.z
	var coated := 0
	for e in _hidden:
		if not is_instance_valid(e):
			continue                       # check BEFORE the cast: casting a freed
		var s := e as Smashable            # object is itself an error in Godot 4
		var to := s.global_position - origin
		var dist := to.length()
		if dist > CLOUD_RANGE:
			continue
		# a cone — except close in, where the cloud simply envelops you and everything
		# in arm's reach, which is also how you find the thing you just walked into
		if dist > CLOUD_ENVELOPE and to.normalized().dot(dir) < cos(CLOUD_ANGLE):
			continue
		_coat(s)
		coated += 1
	return true

func _coat(s: Smashable) -> void:
	_show(s, true)
	s.set_meta("dust_until", Time.get_ticks_msec() + int(COAT_TIME * 1000.0))
	# powder-white wash so a coated object reads as coated, not merely present
	for mi in Floorplan.meshes(s):
		var m := mi as MeshInstance3D
		if m.mesh == null:
			continue
		for i in m.mesh.get_surface_count():
			var src := _surface_material(m, i) as BaseMaterial3D
			if src == null:
				continue
			var d := src.duplicate() as BaseMaterial3D
			d.albedo_color = src.albedo_color.lerp(Color(0.97, 0.96, 0.92), 0.80)
			d.emission_enabled = true
			d.emission = Color(0.55, 0.54, 0.48)
			d.emission_energy_multiplier = 0.55
			m.set_surface_override_material(i, d)

func _spawn_puff() -> void:
	var p := GPUParticles3D.new()
	p.one_shot = true
	p.explosiveness = 0.82
	p.amount = 150
	p.lifetime = 1.1
	p.local_coords = false
	var pm := ParticleProcessMaterial.new()
	pm.emission_shape = ParticleProcessMaterial.EMISSION_SHAPE_SPHERE
	pm.emission_sphere_radius = 0.18
	pm.direction = -_cam.global_transform.basis.z
	pm.spread = 26.0
	pm.initial_velocity_min = 3.0
	pm.initial_velocity_max = 7.5
	pm.damping_min = 3.0
	pm.damping_max = 6.0
	pm.gravity = Vector3(0, -0.6, 0)
	pm.scale_min = 0.5
	pm.scale_max = 1.6
	p.process_material = pm
	var mesh := QuadMesh.new()
	mesh.size = Vector2(0.20, 0.20)
	var mat := StandardMaterial3D.new()
	mat.albedo_color = Color(0.96, 0.94, 0.86, 0.22)
	mat.transparency = BaseMaterial3D.TRANSPARENCY_ALPHA
	mat.billboard_mode = BaseMaterial3D.BILLBOARD_PARTICLES
	mat.shading_mode = BaseMaterial3D.SHADING_MODE_UNSHADED
	mat.cull_mode = BaseMaterial3D.CULL_DISABLED
	mesh.material = mat
	p.draw_pass_1 = mesh
	add_child(p)
	p.global_position = _cam.global_position - _cam.global_transform.basis.z * 0.6
	p.emitting = true
	p.finished.connect(p.queue_free)

# ---------------------------------------------------------------- per-frame
func _process(dt: float) -> void:
	_cd = maxf(0.0, _cd - dt)
	_cough_cd = maxf(0.0, _cough_cd - dt)
	var bloom := 0.0

	if active:
		inhaled = maxf(0.0, inhaled - DECAY * dt)
		# coatings settle
		var now := Time.get_ticks_msec()
		for e in _hidden:
			if not is_instance_valid(e):
				continue
			var s := e as Smashable
			var until := int(s.get_meta("dust_until", 0))
			if until > 0 and now >= until:
				s.set_meta("dust_until", 0)
				_show(s, false)
		# coughing: a jolt, a bloom, and it winds you up
		if inhaled > COUGH_AT and _cough_cd <= 0.0:
			_cough_cd = randf_range(2.4, 4.2)
			_cough_snd.pitch_scale = randf_range(0.9, 1.12)
			_cough_snd.play()
			bloom = 1.0
			if rage != null:
				rage.provoke(0.045, "you are breathing this")
			if _cam != null:
				_cam.rotation.x += randf_range(-0.05, 0.05)
				_cam.rotation.z += randf_range(-0.04, 0.04)

	if _haze != null:
		var m := _haze.material as ShaderMaterial
		m.set_shader_parameter("dust", inhaled)
		m.set_shader_parameter("bloom", bloom)
		_haze.visible = active

# ---------------------------------------------------------------- readouts
func hud_line() -> String:
	if not active:
		return ""
	var lungs := int(round(inhaled * 100.0))
	var warn := "  ·  COUGHING" if inhaled > COUGH_AT else ""
	return "LEVEL 0   ·   RMB: dust (extinguisher)   ·   in your lungs %d%%%s" % [
		lungs, warn]

## A short breath of shaped noise — same zero-asset trick as Juice.gd.
func _make_noise(dur: float, tone: float, decay: float) -> AudioStreamWAV:
	var rate := 22050
	var n := int(rate * dur)
	var out := PackedFloat32Array()
	out.resize(n)
	for i in n:
		var t := float(i) / float(rate)
		var env := exp(-t * decay) * (1.0 - exp(-t * 60.0))
		var s := (randf() * 2.0 - 1.0) * 0.7 * env
		s += sin(TAU * tone * t) * 0.18 * env
		out[i] = clampf(s, -1.0, 1.0)
	var wav := AudioStreamWAV.new()
	wav.format = AudioStreamWAV.FORMAT_16_BITS
	wav.mix_rate = rate
	wav.stereo = false
	var bytes := PackedByteArray()
	bytes.resize(n * 2)
	for i in n:
		bytes.encode_s16(i * 2, int(out[i] * 32767.0))
	wav.data = bytes
	return wav