module HomeHelper

  class ActionedPetitionsDecorator

    FACETS = [

      :awaiting_response,

      :with_response,

      :awaiting_debate,

      :with_debated_outcome,

      :not_debated

     ]

    delegate :each, to: :actioned

    def empty?

      actioned.all? { |_, actioned| actioned[:count].zero? }

    end

    def [](state)

      actioned.fetch(state, 0)

    end

    def with_result

      {:with_response => actioned[:with_response], :with_debated_outcome => actioned[:with_debated_outcome]}

    end

    private

    def actioned

      @actioned ||= generate_actioned

    end

    def generate_actioned(limit = 3)

      scope, facets = Petition.visible, Petition.facet_definitions

      FACETS.each_with_object({}) do |action, actioned|

        facet = scope.instance_exec(&facets[action])

        actioned[action] = { count: facet.count, list: facet.limit(limit) }

      end

    end

  end

  def any_actioned_petitions?

    !actioned_petitions_decorator.empty?

  end

  def actioned_petitions(&block)

    actioned = actioned_petitions_decorator

    yield actioned unless actioned.empty?

  end

  def explanation_petitions(&block)

    yield actioned_petitions_decorator

  end

  def actioned_petitions_decorator

    @_actioned_petitions_decorator ||= ActionedPetitionsDecorator.new

  end

  private :actioned_petitions_decorator

  def no_petitions_yet?

    return @_no_petitions_yet if defined?(@_no_petitions_yet)

    @_no_petitions_yet = Petition.visible.empty?

  end

  def petition_count(key, count)

    t(:"#{key}.html", scope: :"petitions.counts", count: count, formatted_count: number_with_delimiter(count))

  end

  def trending_petitions

    unless Site.disable_trending_petitions?

      petitions = fetch_trending_petitions

      yield petitions unless petitions.empty?

    end

  end

  def fetch_trending_petitions

    Rails.cache.fetch(:trending_petitions, expires_in: 5.minutes) do

      signature_id = Signature.arel_table[:id]

      signature_count = signature_id.count.as("signature_count_in_period")

      Petition.trending.pluck(:id, :action, signature_count.to_sql)

    end

  end

  private :fetch_trending_petitions

end