# Provide attr_reader methods specific to term configuration for linked data authority configurations.  This is separated
# out for readability and file length.
# @see Qa::Authorities::LinkedData::Config
# @see Qa::Authorities::LinkedData::SearchConfig
module Qa::Authorities
  module LinkedData
    class TermConfig
      # @param [Hash] config the term portion of the config
      def initialize(config, prefixes = {})
        @term_config = config
        @prefixes = prefixes
      end

      attr_reader :term_config
      private :term_config

      # Does this authority configuration have term defined?
      # @return [True|False] true if term fetching is configured; otherwise, false
      def supports_term?
        term_config.present?
      end

      # Return term url template defined in the configuration for this authority.
      # @return [Qa::IriTemplate::UrlConfig] the configured term url template
      def url_config
        @url_config ||= Qa::IriTemplate::UrlConfig.new(term_config[:url]) if supports_term?
      end

      # Is the term_id substitution expected to be a URI?
      # @return [True|False] true if the id substitution is expected to be a URI in the term url; otherwise, false
      def term_id_expects_uri?
        return false if term_config.nil? || !(term_config.key? :term_id)
        term_config[:term_id] == "URI"
      end

      # Is the term_id substitution expected to be an ID?
      # @return [True|False] true if the id substitution is expected to be an ID in the term url; otherwise, false
      def term_id_expects_id?
        return false if term_config.nil? || !(term_config.key? :term_id)
        term_config[:term_id] == "ID"
      end

      # Return the preferred language for literal value selection for term fetch.  Only applies if the authority provides language encoded literals.
      # @return [Symbol] the configured language for term fetch (default - :en)
      def term_language
        return @term_language unless @term_language.nil?
        lang = Config.config_value(term_config, :language)
        return nil if lang.nil?
        lang = [lang] if lang.is_a? String
        @term_language = lang.collect(&:to_sym)
      end

      # Return results predicates
      # @return [Hash] all the configured predicates to pull out of the results
      def term_results
        Config.config_value(term_config, :results)
      end

      # Return results id_predicate
      # @return [String] the configured predicate to use to extract the id from the results
      def term_results_id_predicate
        Config.predicate_uri(term_results, :id_predicate)
      end

      # Return results label_predicate
      # @return [String] the configured predicate to use to extract label values from the results
      def term_results_label_predicate
        Config.predicate_uri(term_results, :label_predicate)
      end

      # Return results altlabel_predicate
      # @return [String] the configured predicate to use to extract altlabel values from the results
      def term_results_altlabel_predicate
        Config.predicate_uri(term_results, :altlabel_predicate)
      end

      # Return results broader_predicate
      # @return [String] the configured predicate to use to extract URIs for broader terms from the results
      def term_results_broader_predicate
        Config.predicate_uri(term_results, :broader_predicate)
      end

      # Return results narrower_predicate
      # @return [String] the configured predicate to use to extract URIs for narrower terms from the results
      def term_results_narrower_predicate
        Config.predicate_uri(term_results, :narrower_predicate)
      end

      # Return results sameas_predicate
      # @return [String] the configured predicate to use to extract URIs for sameas terms from the results
      def term_results_sameas_predicate
        Config.predicate_uri(term_results, :sameas_predicate)
      end

      # Return parameters that are required for QA api
      # @return [Hash] the configured term url parameter mappings
      def term_qa_replacement_patterns
        Config.config_value(term_config, :qa_replacement_patterns)
      end
      alias qa_replacement_patterns term_qa_replacement_patterns

      # Are there subauthorities configured for term fetch?
      # @return [True|False] true if there are subauthorities configured term fetch; otherwise, false
      def term_subauthorities?
        term_subauthority_count.positive?
      end

      # Is a specific subauthority configured for term fetch?
      # @return [True|False] true if the specified subauthority is configured for term fetch; otherwise, false
      def term_subauthority?(subauth_name)
        subauth_name = subauth_name.to_sym if subauth_name.is_a? String
        term_subauthorities.key? subauth_name
      end

      # Return the number of subauthorities defined for term fetch
      # @return [Integer] the number of subauthorities defined for term fetch
      def term_subauthority_count
        term_subauthorities.size
      end

      # Return the list of subauthorities for term fetch
      # @return [Hash] the configurations for term url replacements
      def term_subauthorities
        @term_subauthorities ||= {} if term_config.nil? || !(term_config.key? :subauthorities)
        @term_subauthorities ||= term_config[:subauthorities]
      end
      alias subauthorities term_subauthorities
    end
  end
end