shioyama/mobility

# frozen-string-literal: true

module Mobility
  module Plugins
=begin

Defines +method_missing+ and +respond_to_missing?+ methods for a set of
attributes such that a method call using a locale accessor, like:

  article.title_pt_br

will return the value of +article.title+ with the locale set to +pt-BR+ around
the method call. The class is called "FallthroughAccessors" because when
included in a model class, locale-specific methods will be available even if
not explicitly defined with the +locale_accessors+ option.

This is a less efficient (but more open-ended) implementation of locale
accessors, for use in cases where the locales to be used are not known when the
model class is generated.

=end
    module FallthroughAccessors
      extend Plugin

      default true

      # Apply fallthrough accessors plugin to attributes.
      # @param [Translations] translations
      # @param [Boolean] option
      initialize_hook do
        if options[:fallthrough_accessors]
          define_fallthrough_accessors(names)
        end
      end

      private

      def define_fallthrough_accessors(*names)
        method_name_regex = /\A(#{names.join('|')})_([a-z]{2,3}(_[a-z]{2})?)(=?|\??)\z/.freeze

        define_method :method_missing do |method_name, *args, &block|
          if method_name =~ method_name_regex
            attribute_method = "#{$1}#{$4}"
            locale, suffix = $2.split('_')
            locale = "#{locale}-#{suffix.upcase}" if suffix
            if $4 == '=' # writer
              kwargs = args[1].is_a?(Hash) ? args[1] : {}
              public_send(attribute_method, args[0], **kwargs, locale: locale)
            else         # reader
              kwargs = args[0].is_a?(Hash) ? args[0] : {}
              public_send(attribute_method, **kwargs, locale: locale)
            end
          else
            super(method_name, *args, &block)
          end
        end

        # Following is needed in order to not swallow `kwargs` on ruby >= 3.0.
        # Otherwise `kwargs` are not passed by `super` to a possible other
        # `method_missing` defined like this:
        #
        # def method_missing(name, *args, **kwargs, &block); end
        ruby2_keywords :method_missing

        define_method :respond_to_missing? do |method_name, include_private = false|
          (method_name =~ method_name_regex) || super(method_name, include_private)
        end
      end
    end

    register_plugin :fallthrough_accessors, FallthroughAccessors
  end
end