class_name ComboWindow
extends Node

signal combo_updated(inputs: Array[StringName])
signal combo_cleared(reason: StringName)

@export var size := 4
@export var clear_display_time := 0.35

var slots: Array[StringName] = []
var pending_clear_reason: StringName = &""
var _timer: Timer


func _ready() -> void:
	_timer = Timer.new()
	_timer.one_shot = true
	_timer.timeout.connect(flush_pending_clear)
	add_child(_timer)


func record(input: StringName) -> void:
	if input.is_empty():
		return
	slots.append(input)
	combo_updated.emit(get_slots())
	_emit_bus_signal("combo_updated", [get_slots()])
	if slots.size() >= size:
		queue_clear(&"full")


func get_slots() -> Array[StringName]:
	return slots.duplicate()


func has_pending_clear() -> bool:
	return not pending_clear_reason.is_empty()


func consume_pending_clear_reason() -> StringName:
	var reason := pending_clear_reason
	pending_clear_reason = &""
	return reason


func get_pattern() -> String:
	var pattern := ""
	for slot: StringName in slots:
		if slot != &"Ø":
			pattern += str(slot)
	return pattern


func get_contiguous_pattern() -> String:
	var pattern := ""
	for index: int in range(slots.size() - 1, -1, -1):
		var slot := slots[index]
		if slot == &"Ø":
			break
		pattern = str(slot) + pattern
	return pattern


func queue_clear(reason: StringName, delay := -1.0) -> void:
	pending_clear_reason = reason
	if _timer == null:
		return
	_timer.stop()
	_timer.wait_time = clear_display_time if delay < 0.0 else delay
	_timer.start()


func cancel_pending_clear() -> void:
	pending_clear_reason = &""
	if _timer != null:
		_timer.stop()


func flush_pending_clear() -> void:
	var reason := consume_pending_clear_reason()
	if reason.is_empty():
		return
	if _timer != null:
		_timer.stop()
	clear(reason)


func clear(reason: StringName = &"") -> void:
	slots.clear()
	pending_clear_reason = &""
	combo_cleared.emit(reason)
	_emit_bus_signal("combo_cleared", [reason])
	combo_updated.emit(get_slots())
	_emit_bus_signal("combo_updated", [get_slots()])


func _emit_bus_signal(signal_name: StringName, args: Array) -> void:
	if not is_inside_tree():
		return
	var bus := _event_bus_or_null()
	if bus != null:
		bus.emit_signal(signal_name, args[0])


func _event_bus_or_null() -> Node:
	if not is_inside_tree():
		return null
	return get_tree().root.get_node_or_null("EventBus")