# encoding: utf-8
require_relative "messages"

module Hexx
  module Helpers

    # @api hide
    # The module declares instance helper methods to provide validations
    module Exceptions
      extend ActiveSupport::Concern
      include ActiveModel::Validations
      include Messages

      # @api hide
      # Class helper methods
      module ClassMethods

        def raises(*names)
          fail ArgumentError if (types = names.flatten.map(&:to_s)) == []
          types.each { |type| add_exception(type) }
        end

        private

        def add_exception(type)
          check type
          class_eval "class #{ type } < StandardError; end"
        end

        def check(type)
          return if type[/([A-Z][a-z]+)+/]
          fail TypeError.new(
            %(Wrong exception name "#{ type }". Use words in camel-case only.)
          )
        end
      end

      def on_error(messages)
        messages.map(&:text).each { |text| errors.add :base, text }
        fail Hexx::ServiceInvalid.new(self)
      end

      def escape
        yield
      rescue Hexx::ServiceInvalid => err
        raise err
      rescue => err
        errors.add :base, err.message
        raise Hexx::ServiceInvalid.new(self)
      end
    end
  end
end