class Faker::JapaneseMedia::KamenRider

def collectible_device(*eras)
  from_eras(*eras, field: :collectible_devices) { |e| e.delete(:showa) }
end

def eras
  @eras ||= ERAS
end

def eras=(new_eras)
  selected_eras = ERAS & new_eras
  @eras = selected_eras.empty? ? ERAS : selected_eras
end

def from_eras(*input_eras, field:)
  selected_eras = (ERAS & input_eras).then do |selected|
    selected.empty? ? eras : selected
  end.dup
  yield(selected_eras) if block_given?
  raise UnavailableInEra, "#{field} is unavailable in the selected eras." if selected_eras.empty?
  selected_eras.sample.then do |era|
    fetch("kamen_rider.#{era}.#{field}")
  end
end

def kamen_rider(*eras)
  from_eras(*eras, field: :kamen_riders)
end

def series(*eras)
  from_eras(*eras, field: :series)
end

def transformation_device(*eras)
  from_eras(*eras, field: :transformation_devices)
end

def user(*eras)
  from_eras(*eras, field: :users)
end