# frozen_string_literal: true

module Cocina
  module Models
    module Mapping
      module Normalizers
        module Mods
          # Normalizes a Fedora MODS document for title elements.
          class TitleNormalizer
            # @param [Nokogiri::Document] mods_ng_xml MODS to be normalized
            # @param [String] label
            # @return [Nokogiri::Document] normalized MODS
            def self.normalize(mods_ng_xml:, label:)
              new(mods_ng_xml: mods_ng_xml, label: label).normalize
            end

            def self.normalize_missing_title(mods_ng_xml:, label:)
              new(mods_ng_xml: mods_ng_xml, label: label).normalize_missing_title
            end

            def initialize(mods_ng_xml:, label:)
              @ng_xml = mods_ng_xml.dup
              @ng_xml.encoding = 'UTF-8'
              @label = label
            end

            def normalize
              normalize_hydrus_title
              clean_empty_titles
              normalize_title_type
              normalize_title_trailing
              normalize_title_as_label
              ng_xml
            end

            def normalize_missing_title
              normalize_title_as_label
              ng_xml
            end

            private

            attr_reader :ng_xml, :label

            def normalize_hydrus_title
              titles = ng_xml.root.xpath('mods:titleInfo/mods:title[string-length() > 0]', mods: ModsNormalizer::MODS_NS)
              return if titles.present? || label != 'Hydrus'

              add_title('Hydrus')
            end

            def clean_empty_titles
              ng_xml.root.xpath('//mods:title[not(text())]', mods: ModsNormalizer::MODS_NS).each(&:remove)
              ng_xml.root.xpath('//mods:subTitle[not(text())]', mods: ModsNormalizer::MODS_NS).each(&:remove)
              ng_xml.root.xpath('//mods:titleInfo[not(mods:*) and not(@xlink:href)]',
                                mods: ModsNormalizer::MODS_NS, xlink: ModsNormalizer::XLINK_NS).each(&:remove)
            end

            def normalize_title_type
              ng_xml.root.xpath('//mods:title[@type]', mods: ModsNormalizer::MODS_NS).each do |title_node|
                title_node.delete('type')
              end
            end

            def normalize_title_trailing
              ng_xml.root.xpath('//mods:titleInfo[not(@type="abbreviated")]/mods:title', mods: ModsNormalizer::MODS_NS).each do |title_node|
                title_node.content = title_node.content.delete_suffix(',')
              end
            end

            def normalize_title_as_label
              return if ng_xml.root.xpath('mods:titleInfo/mods:title',
                                          mods: ModsNormalizer::MODS_NS).present? || ng_xml.root.xpath('mods:titleInfo[@xlink:href]', mods: ModsNormalizer::MODS_NS,
                                                                                                                                      xlink: ModsNormalizer::XLINK_NS).present?

              add_title(label)
            end

            def add_title(content)
              new_title_info = Nokogiri::XML::Node.new('titleInfo', Nokogiri::XML(nil))
              new_title = Nokogiri::XML::Node.new('title', Nokogiri::XML(nil))
              new_title.content = content
              new_title_info << new_title
              ng_xml.root << new_title_info
            end
          end
        end
      end
    end
  end
end