module ErpApp
  module Extensions
    module ActiveRecord
      module HasUserPreferences

        def self.included(base)
          base.extend(ClassMethods)
        end

        module ClassMethods

          def has_user_preferences()
            has_many :user_preferences, :as => :preferenced_record

            extend HasUserPreferences::SingletonMethods
            include HasUserPreferences::InstanceMethods
          end
        end

        module SingletonMethods
        end

        module InstanceMethods

          def preferences(user)
            self.user_preferences.includes([:preference]).where('user_id = ?', user.id).map(&:preference)
          end

          def set_user_preference(user, preference_type_iid, preference_option_lookup)
            preference_type = PreferenceType.find_by_internal_identifier(preference_type_iid.to_s)
            preference_option = nil
            #preference option can be set using
            #:default [symbol which will set to default for preference type]
            #:preference_option_iid [the internal identifier for the preference option]
            #:value [the value of the preference_option]

            preference_option = preference_type.default_option if preference_option_lookup == :default
            preference_option = preference_type.preference_options.where('internal_identifier = ?', preference_option_lookup.to_s).first if preference_option.nil?
            preference_option = preference_type.preference_options.where('value = ?', preference_option_lookup.to_s).first if preference_option.nil?

            if preference_option.nil?
              raise 'Invalid option for preference type'
            else
              preference = find_user_preference(user, preference_type)
              unless preference.nil?
                preference.preference_option = preference_option
                preference.save
              else
                preference = Preference.create(:preference_type => preference_type, :preference_option => preference_option)
                self.user_preferences << UserPreference.create(:preference => preference, :user => user)
                self.save
              end
            end
          end

          def get_user_preference(user, preference_type_iid)
            preference_type = PreferenceType.find_by_internal_identifier(preference_type_iid.to_s)
            preference = find_user_preference(user, preference_type)
            if preference.nil?
              preference_type.default_preference_option.value
            else
              preference.preference_option.value
            end
          end

          private

          def find_user_preference(user, preference_type)
            preference = nil
            results = self.user_preferences.includes([:preference]).where('user_id = ? and preferences.preference_type_id = ?', user.id, preference_type.id)
            if !results.nil? && !results.empty?
              preference = results.first.preference
            end
            preference
          end
        end

      end # HasUserPreferences
    end # ActiveRecord
  end # Extensions
end # ErpApp