Mini state machine

mini_state_machine.rb

# THIS IS WIP, NOT FULLY WORKING

class MiniStateMachine

  # [initial_statuses, event, next_status]
  @transitions = [
    [[:s1, :s2], :event1, :s3],
    [[:s3],      :event2, :s4],
    [[:s1, :s2], :event3, :s5]
  ]

  def initialize(state)
    raise 'State do not exist' unless all_statuses.include? state

    @current_state = state
  end

  def apply_event!(event)
    transition = @transitions
      .find { |statuses, event_for_statuses, final_state|  
        statuses.include? current_state && event_for_statuses == event
      }

    new_state = transition[2]
    new_state
  end

  private

  def all_statuses
    @transitions
      .map { |transition| transition.first }
      .flatten
      .uniq
  end

end