class_name Stars
extends Control
## A row of stars, [member filled] of [member count] lit. Earned stars pop in one by one
## when [method reveal] is called.

@export var count := 3:
	set(value):
		count = value
		_resize()
@export var filled := 0:
	set(value):
		filled = value
		queue_redraw()
@export var star_size := 36.0:
	set(value):
		star_size = value
		_resize()
@export var spacing := 10.0

## Per-star scale while popping in.
var _pop: Array[float] = [1.0, 1.0, 1.0]


func _ready() -> void:
	_resize()


## Lights the first [param stars] stars one after another with a small pop.
func reveal(stars: int) -> void:
	filled = stars
	_pop.resize(count)
	_pop.fill(0.0)
	var tween := create_tween()
	for i in count:
		tween.tween_method(_set_pop.bind(i), 0.0, 1.0, 0.25).set_trans(Tween.TRANS_BACK).set_ease(Tween.EASE_OUT)


func _set_pop(value: float, index: int) -> void:
	_pop[index] = value
	queue_redraw()


func _resize() -> void:
	custom_minimum_size = Vector2(count * star_size + (count - 1) * spacing, star_size)
	_pop.resize(count)
	for i in count:
		if _pop[i] == 0.0:
			_pop[i] = 1.0
	queue_redraw()


func _draw() -> void:
	var start := (size.x - custom_minimum_size.x) / 2.0
	for i in count:
		var center := Vector2(start + star_size / 2.0 + i * (star_size + spacing), size.y / 2.0)
		var lit := i < filled
		var color := Params.COLOR_ORANGE if lit else Color(1, 1, 1, 0.15)
		var points := _star_points(center, star_size / 2.0 * (_pop[i] if lit else 1.0))
		draw_colored_polygon(points, color)
		points.append(points[0])
		draw_polyline(points, color, 1.0, true)


static func _star_points(center: Vector2, radius: float) -> PackedVector2Array:
	var points := PackedVector2Array()
	for i in 10:
		var r := radius if i % 2 == 0 else radius * 0.45
		var angle := -PI / 2.0 + i * PI / 5.0
		points.append(center + Vector2(cos(angle), sin(angle)) * r)
	return points