Refactor rhythm action architecture

scenes/components/state_machine.gd

@@ -0,0 +1,34 @@
+class_name StateMachine
+extends Node
+
+signal state_changed(previous: int, current: int)
+
+var current_state := 0
+var state_names: Array[StringName] = [
+	&"ground",
+	&"ground",
+	&"air",
+	&"ground",
+	&"ground",
+	&"air",
+	&"guarding",
+	&"charging",
+	&"bladeChain",
+	&"burstCharge",
+	&"bursting",
+	&"hitstun",
+]
+
+
+func change_state(next_state: int) -> void:
+	if next_state == current_state:
+		return
+	var previous := current_state
+	current_state = next_state
+	state_changed.emit(previous, current_state)
+
+
+func get_current_state_name() -> StringName:
+	if current_state >= 0 and current_state < state_names.size():
+		return state_names[current_state]
+	return &"any"