# frozen_string_literal: true

module ModsDisplay
  class RelatedItem < Field
    include ModsDisplay::RelatedItemConcerns

    def fields
      return_fields = @values.map do |value|
        next if related_item_is_a_collection?(value)
        next if render_nested_related_item?(value)

        if related_item_is_a_location?(value)
          process_location value
        elsif related_item_is_a_reference?(value)
          process_reference value
        else
          process_related_item(value)
        end
      end.compact
      collapse_fields(return_fields)
    end

    private

    def delimiter
      '<br />'
    end

    def process_location(item)
      ModsDisplay::Values.new(label: related_item_label(item), values: [item.location.text.strip])
    end

    def process_reference(item)
      ModsDisplay::Values.new(label: related_item_label(item), values: [reference_title(item)])
    end

    def process_related_item(item)
      return unless item.titleInfo.length.positive?

      title = item.titleInfo.text.strip
      return_text = title
      location = nil
      location = item.location.url.text if item.location.length.positive? &&
                                           item.location.url.length.positive?
      return_text = "<a href='#{location}'>#{title}</a>" if location && !title.empty?

      ModsDisplay::Values.new(label: related_item_label(item), values: [return_text]) unless return_text.empty?
    end

    def reference_title(item)
      [item.titleInfo,
       item.originInfo.dateOther,
       item.part.detail.number,
       item.note].flatten.compact.map!(&:text).map!(&:strip).join(' ')
    end

    def related_item_is_a_location?(item)
      !related_item_is_a_collection?(item) &&
        !related_item_is_a_reference?(item) &&
        item.location.length.positive? &&
        item.titleInfo.empty?
    end

    def related_item_is_a_reference?(item)
      !related_item_is_a_collection?(item) &&
        item.attributes['type'].respond_to?(:value) &&
        item.attributes['type'].value == 'isReferencedBy'
    end

    def related_item_label(item)
      if displayLabel(item)
        displayLabel(item)
      else
        case
        when related_item_is_a_location?(item)
          return I18n.t('mods_display.location')
        when related_item_is_a_reference?(item)
          return I18n.t('mods_display.referenced_by')
        end
        I18n.t('mods_display.related_item')
      end
    end
  end
end