class Fusuma::Plugin::Buffers::GestureBuffer

def avg_attrs(attr)
  sum_attrs(attr).to_f / updating_events.length
end

def buffer(event)
  # TODO: buffering events into buffer plugins
  # - gesture event buffer
  # - window event buffer
  # - other event buffer
  return if event&.tag != source
  @events.push(event)
  self
end

def clear_expired(current_time: Time.now)
  clear if ended?
  @seconds_to_keep ||= (config_params(:seconds_to_keep) || DEFAULT_SECONDS_TO_KEEP)
  @events.each do |e|
    break if current_time - e.time < @seconds_to_keep
    MultiLogger.debug("#{self.class.name}##{__method__}")
    @events.delete(e)
  end
end

def config_param_types
  {
    source: [String],
    seconds_to_keep: [Float, Integer]
  }
end

def empty?
  @events.empty?
end

def ended?
  return false if empty?
  @events.last.record.status == 'end'
end

def finger
  @events.last.record.finger.to_i
end

def gesture
  @events.last.record.gesture
end

def select_by_events(&block)
  return enum_for(:select_by_events) unless block_given?
  events = @events.select(&block)
  self.class.new events
end

def select_from_last_begin
  return self if empty?
  index_from_last = @events.reverse.find_index { |e| e.record.status == 'begin' }
  return GestureBuffer.new([]) if index_from_last.nil?
  index_last_begin = events.length - index_from_last - 1
  GestureBuffer.new(@events[index_last_begin..-1])
end

def sum_attrs(attr)
  updating_events.map do |gesture_event|
    gesture_event.record.delta[attr].to_f
  end.inject(:+)
end

def updating_events
  @events.select { |e| e.record.status == 'update' }
end