module Playbook::Shadow

def self.included(base)
  base.prop :shadow
end

def shadow_options
  {
    shadow: "shadow",
  }
end

def shadow_props
  selected_props = shadow_options.keys.select { |sk| try(sk) }
  return nil unless selected_props.present?
  selected_props.map do |k|
    shadow_value = send(k)
    "shadow_#{shadow_value}" if shadow_values.include? shadow_value
  end.compact.join(" ")
end

def shadow_values
  %w[none deep deeper deepest]
end