Refactor rhythm action architecture

scenes/components/energy_component.gd

@@ -0,0 +1,54 @@
+class_name EnergyComponent
+extends Node
+
+signal energy_changed(current: int, maximum: int)
+
+@export var maximum := 10
+@export var current := 0
+
+
+func _ready() -> void:
+	_emit_changed()
+
+
+func set_values(next_current: int, next_maximum: int) -> void:
+	maximum = max(1, next_maximum)
+	current = clampi(next_current, 0, maximum)
+	_emit_changed()
+
+
+func set_current(next_current: int) -> void:
+	var clamped := clampi(next_current, 0, maximum)
+	if clamped == current:
+		return
+	current = clamped
+	_emit_changed()
+
+
+func change(delta: int) -> void:
+	set_current(current + delta)
+
+
+func spend(cost: float) -> bool:
+	var int_cost := int(ceil(cost))
+	if int_cost <= 0:
+		return true
+	if current < int_cost:
+		return false
+	set_current(current - int_cost)
+	return true
+
+
+func _emit_changed() -> void:
+	energy_changed.emit(current, maximum)
+	_event_bus().emit_signal("player_energy_changed", float(current), float(maximum))
+
+
+func _event_bus() -> Node:
+	var root := get_tree().root
+	var bus := root.get_node_or_null("EventBus")
+	if bus == null:
+		bus = load("res://autoload/event_bus.gd").new()
+		bus.name = "EventBus"
+		root.add_child(bus)
+	return bus