require_relative '../base'

module CCS
  module Components
    module GovUK
      # = GOV.UK Notification Banner
      #
      # This helper is used for generating the notification banner component from the
      # {https://design-system.service.gov.uk/components/notification-banner GDS - Components - Notification banner}
      #
      # @!attribute [r] text
      #   @return [String] Text for the notification banner
      # @!attribute [r] success_banner
      #   @return [Boolean] Indicates if this is a success banner

      class NotificationBanner < Base
        private

        attr_reader :text, :success_banner

        public

        # @param text [String] the text that will be used for the heading in the content section of the banner.
        #                      It is ignored if a block is given
        # @param success_banner [Boolean] will use the success banner options if this is set to true
        # @param options [Hash] options that will be used in customising the HTML
        #
        # @option options [String] :classes additional CSS classes for the notification banner HTML
        # @option options [String] :title_text ('Important') the title text shown at the top of the banner
        # @option options [String] :title_id ('govuk-notification-banner-title') the ID for the title text
        # @option options [String] :role ('region') the role for the banner
        # @option options [String] :heading_level (2) the heading level for the title text
        # @option options [Hash] :attributes ({}) any additional attributes that will added as part of the HTML

        def initialize(text: nil, success_banner: nil, **options)
          super(**options)

          @text = text
          @success_banner = success_banner || false

          set_additional_options_for_banner
        end

        # Generates the HTML for the GOV.UK Notification banner component
        #
        # @yield HTML that will be contained within the 'govuk-notification-banner__content' div
        #
        # @return [ActiveSupport::SafeBuffer]

        def render
          tag.div(**options[:attributes]) do
            concat(tag.div(class: 'govuk-notification-banner__header') do
              tag.send(:"h#{options[:heading_level] || 2}", options[:title_text], class: 'govuk-notification-banner__title', id: options[:title_id])
            end)
            concat(tag.div(class: 'govuk-notification-banner__content') do
              if block_given?
                yield
              else
                tag.p(text, class: 'govuk-notification-banner__heading')
              end
            end)
          end
        end

        # The default attributes for the notifaction banner

        DEFAULT_ATTRIBUTES = { class: 'govuk-notification-banner', data: { module: 'govuk-notification-banner' } }.freeze

        # Default options used in normal versions of the notification banner

        DEFAULT_OPTIONS = {
          title_text: 'Important',
          title_id: 'govuk-notification-banner-title',
          role: 'region'
        }.freeze

        # Specific options for the success version of the notification banner

        SUCCESS_BANNER_OPTIONS = {
          classes: ' govuk-notification-banner--success',
          title_text: 'Success',
          role: 'alert'
        }.freeze

        private

        # rubocop:disable Metrics/AbcSize

        # Determines the banner options to be used for the notification banner

        def set_additional_options_for_banner
          banner_options = DEFAULT_OPTIONS.dup

          banner_options.merge!(SUCCESS_BANNER_OPTIONS) if success_banner

          options[:title_text] ||= banner_options[:title_text]
          options[:title_id] ||= banner_options[:title_id]
          options[:attributes][:role] ||= banner_options[:role]
          options[:attributes][:class] << banner_options[:classes].to_s
          (options[:attributes][:aria] ||= {})[:labelledby] = options[:title_id]
        end

        # rubocop:enable Metrics/AbcSize
      end
    end
  end
end