jwaldrip/memory_model

module MemoryModel

  class RecordInvalid < MemoryModel::Error
    attr_reader :record # :nodoc:
    def initialize(record) # :nodoc:
      @record = record
      errors  = @record.errors.full_messages.join(", ")
      super(errors)
    end
  end

  class Base
    module Actions
      extend ActiveSupport::Concern
      extend ActiveSupport::Autoload

      autoload :ClassMethods

      included do
        define_model_callbacks :create, :update, :save, :destroy, :validation
        define_model_callbacks :commit, only: :after
        before_save(:remove_invalid_instance_vars)
      end

      VALID_IVARS = [
        :@attributes
      ]

      def delete
        self.class.collection.delete(self)
        freeze
      end

      def destroy
        run_callbacks :destroy do
          delete
        end
      end

      def save(options={})
        !!perform_validations(options) ? commit : false
      end

      def save!(options={})
        !!perform_validations(options) ? commit : raise(RecordInvalid.new(self))
      end

      private

      def commit
        operation = persisted? ? :update : :create
        run_callbacks operation do
          run_callbacks :save do
            self.class.collection.send(operation, self)
            run_callbacks :commit
          end
        end
        self
      end

      def remove_invalid_instance_vars
        instance_variables.reject { |ivar| ivar.in? VALID_IVARS }.each do |ivar|
          remove_instance_variable ivar if instance_variable_defined?(ivar)
        end
      end

      def perform_validations(options={})
        run_callbacks :validation do
          options[:validate] == false || valid?(options[:context])
        end
      end

    end
  end
end