Arcath/Adauth

module Adauth
    module Rails
        # Included into Models in Rails
        #
        # Requires you to set 2 Constants
        #
        # AdauthMappings
        #
        # A hash which controls how Adauth maps its values to rails e.g.
        #
        # AdauthMappings = {
        #   :name => :login
        # }
        #
        # This will store Adauths 'login' value in the 'name' field.
        #
        # AdauthSearchField
        #
        # This is an array which contains 2 values and is used to find the objects record e.g.
        #
        # AdauthSearchField = [:login, :name]
        #
        # This will cause RailsModel.where(:name => AdauthObject.login).first_or_initialize
        #
        # The Order is [adauth_field, rails_field]
        module ModelBridge
            # Registers the class methods when ModelBridge is included
            def self.included(base)
                base.extend ClassMethods
            end

            # Uses AdauthMappings to update the values on the model using the ones from Adauth
            def update_from_adauth(adauth_model)
                self.class::AdauthMappings.each do |k, v|
                    setter = "#{k.to_s}=".to_sym
                    value = v.is_a?(Array) ? v.join(", ") : v

                    # ensure the attribute exists in the collected data and only assign if it does
                    if adauth_model.respond_to?(value)
                      self.send(setter, adauth_model.send(value))
                    end
                end
                self.save
                self
            end

            # Class Methods for ModelBridge
            module ClassMethods
                # Creates a new RailsModel from the adauth_model
                def create_from_adauth(adauth_model)
                    rails_model = self.new
                    rails_model.update_from_adauth(adauth_model)
                end

                # Used to create the RailsModel if it doesn't exist and update it if it does
                def return_and_create_from_adauth(adauth_model)
                    adauth_field = self::AdauthSearchField.first
                    adauth_search_value = adauth_model.send(adauth_field)
                    rails_search_field = self::AdauthSearchField.second
                    # Model#where({}).first_or_initialize is also compatible with Mongoid (3.1.0+)
                    rails_model = self.send(:where, { rails_search_field => adauth_search_value }).first_or_initialize
                    rails_model.update_from_adauth(adauth_model)
                    rails_model
                end
            end
        end
    end
end