extends Node2D

const DURATION := 0.85
static var _sounds: Dictionary = {}
static var _last_sound_ms := -1000
var tint := Color("91dbea")
var quality := 0
var age := 0.0

static func spawn(parent: Node, at: Vector2, color: Color, rarity: int = 0, screen_audio: bool = false) -> Node2D:
	var effect := Node2D.new()
	effect.set_script(load("res://scripts/items/loot_reveal_effect.gd"))
	effect.tint = color
	effect.quality = clampi(rarity,0,4)
	effect.position = at
	parent.add_child(effect)
	# Simultaneous drops share one chime, keeping battles from becoming too loud.
	var now := Time.get_ticks_msec()
	if now-_last_sound_ms >= 100:
		_last_sound_ms = now
		var audio: Node
		if screen_audio:
			audio = AudioStreamPlayer.new()
		else:
			audio = AudioStreamPlayer2D.new()
			audio.max_distance = 1200.0
			audio.attenuation = 1.5
		audio.stream = sound(quality_band(rarity))
		audio.volume_db = -12.0
		if AudioServer.get_bus_index("SFX") >= 0: audio.bus = &"SFX"
		effect.add_child(audio)
		audio.play()
	return effect

static func quality_band(rarity: int) -> int:
	return 1 if rarity >= 3 else 0

static func sound(band: int = 0) -> AudioStreamWAV:
	if _sounds.has(band): return _sounds[band]
	var rate := 22050
	var length := 0.65
	var data := PackedByteArray()
	data.resize(int(rate*length)*2)
	for index in int(rate*length):
		var t := float(index)/rate
		var value := 0.0
		for note in 3:
			var elapsed := t-note*0.075
			if elapsed < 0.0: continue
			var frequency: float = [659.25,830.61,987.77][note]*(1.25 if band > 0 else 1.0)
			var envelope := minf(elapsed/0.006,1.0)*exp(-elapsed*9.0)
			value += (sin(TAU*frequency*elapsed)+0.18*sin(TAU*frequency*2.0*elapsed))*envelope*0.18
		data.encode_s16(index*2,clampi(roundi(value*32767),-32768,32767))
	var stream := AudioStreamWAV.new()
	stream.format = AudioStreamWAV.FORMAT_16_BITS
	stream.mix_rate = rate
	stream.data = data
	_sounds[band] = stream
	return stream

func _ready() -> void:
	z_index = 30

func _process(delta: float) -> void:
	age += delta
	if age >= DURATION:
		queue_free()
		return
	queue_redraw()

func _draw() -> void:
	var progress := clampf(age/DURATION,0.0,1.0)
	var fade := pow(1.0-progress,2.0)
	var radius := 16.0+75.0*(1.0-pow(1.0-progress,3.0))
	for layer in range(4,0,-1):
		draw_circle(Vector2.ZERO,12.0+layer*8.0,Color(tint,fade*0.035))
	draw_arc(Vector2.ZERO,radius,0,TAU,64,Color(tint,fade*0.8),1.4,true)
	for index in 14+quality*2:
		var angle := index*2.39996
		var direction := Vector2.from_angle(angle)
		var distance := (18.0+float(index%4)*8.0)+progress*(42.0+float(index%3)*18.0)
		var point := direction*distance
		draw_line(point,point-direction*(3.0+8.0*(1.0-progress)),Color(tint,fade),1.5,true)
	var beam := maxf(0.0,1.0-age/0.45)
	draw_line(Vector2(0,12),Vector2(0,-92-quality*12),Color(tint,beam*0.65),2.0,true)
	draw_line(Vector2(-10,0),Vector2(10,0),Color.WHITE*Color(1,1,1,beam),2.0,true)