sul-dlss/dor-services-app

# frozen_string_literal: true

module Indexing
  module Builders
    # Builds the event date fields for a solr document
    class EventDateBuilder
      # @param [Cocina::Models::Event] event single selected  event
      # @return [String, nil] the date value for Solr
      def self.build(event, date_type)
        event_dates = Array(event&.date) + Array(event&.parallelEvent&.map(&:date))

        matching_date_value_with_status_primary(event_dates, date_type) ||
          matching_date_value(event_dates, date_type) ||
          untyped_date_value(event_dates)
      end

      # @return [String, nil] date.value from a date of type of date_type and of status primary
      def self.matching_date_value_with_status_primary(event_dates, date_type)
        event_dates.flatten.compact.find do |date|
          next if date.type != date_type

          next unless Indexing::Selectors::EventSelector.date_status_primary(date)

          return date_value(date)
        end
      end
      private_class_method :matching_date_value_with_status_primary

      # @return [String, nil] date.value from a date of type of date_type
      def self.matching_date_value(event_dates, date_type)
        event_dates.flatten.compact.find do |date|
          next if date.type != date_type

          return date_value(date)
        end
      end
      private_class_method :matching_date_value

      # @return [String, nil] date.value from a date without a type
      def self.untyped_date_value(event_dates)
        event_dates.flatten.compact.find do |date|
          next if date.type.present?

          return date_value(date)
        end
      end
      private_class_method :untyped_date_value

      # @param [Cocina::Models::DescriptiveValue] a date object from an event
      # @return [String, nil] value from date object
      def self.date_value(date)
        return date.value if date&.value.present?

        Array(date&.structuredValue).find do |structured_value|
          return structured_value.value if structured_value&.value.present?
        end

        Array(date&.parallelValue).find do |parallel_value|
          return parallel_value.value if parallel_value&.value.present?
        end
      end
      private_class_method :date_value
    end
  end
end