# frozen_string_literal: true

module Grammar
  # Functions to select pronouns based on an entity's attributes, such as
  # gender.
  #
  module Pronoun
    class << self
      # @param entity [#person, #plural?, #gender]
      # @return [String]
      def subjective(entity)
        map(entity)[:subjective]
      end
      alias they subjective
      alias he subjective
      alias she subjective

      # @param entity [#person, #plural?, #gender]
      # @return [String]
      def subjective_(entity)
        subjective(entity).cap_first
      end
      alias they_ subjective_
      alias he_ subjective_
      alias she_ subjective_

      # @param entity [#person, #plural?, #gender]
      # @return [String]
      def objective(entity)
        map(entity)[:objective]
      end
      alias them objective

      # @param entity [#person, #plural?, #gender]
      # @return [String]
      def objective_(entity)
        objective(entity).cap_first
      end
      alias them_ objective_

      # @param entity [#person, #plural?, #gender]
      # @return [String]
      def possessive(entity)
        map(entity)[:possessive]
      end
      alias their possessive

      # @param entity [#person, #plural?, #gender]
      # @return [String]
      def possessive_(entity)
        possessive(entity).cap_first
      end
      alias their_ possessive_

      # @param entity [#person, #plural?, #gender]
      # @return [String]
      def reflexive(entity)
        map(entity)[:reflexive]
      end
      alias themselves reflexive
      alias themself reflexive

      # @param entity [#person, #plural?, #gender]
      # @return [String]
      def reflexive_(entity)
        reflexive(entity).cap_first
      end
      alias themselves_ reflexive_
      alias themself_ reflexive_

      # @param entity [#person, #plural?, #gender]
      # @return [Hash]
      def map(entity)
        plurality = (entity.plural? ? :plural : :singular)
        maps[[(entity.person || 3), plurality, entity.gender]] ||
          maps[[(entity.person || 3), plurality]]
      end

      private

      def maps
        @maps ||= {
          [1, :singular] => Hash[map_keys.zip(%w[I me my myself])],
          [2, :singular] => Hash[map_keys.zip(%w[you you your yourself])],
          [3, :singular] => Hash[map_keys.zip(%w[it it its itself])],
          [3, :singular, :male] => Hash[map_keys.zip(%w[he him his himself])],
          [3, :singular, :female] => Hash[map_keys.zip(%w[she her her herself])],
          [3, :singular, :other] => Hash[map_keys.zip(%w[they them their themselves])],
          [3, :singular, :neutral] => Hash[map_keys.zip(%w[it it its itself])],
          [1, :plural] => Hash[map_keys.zip(%w[we us our ourselves])],
          [2, :plural] => Hash[map_keys.zip(%w[you you your yourselves])],
          [3, :plural] => Hash[map_keys.zip(%w[they them their themselves])]
        }
      end

      def map_keys
        @map_keys ||= %i[subjective objective possessive reflexive]
      end
    end
  end
end