module Aws
  module EC2
    module Plugins
      # @api private
      class RegionValidation < Seahorse::Client::Plugin

        def after_initialize(client)
          if region = client.config.region
            if matches = region.match(/^(\w+-\w+-\d+)[a-z]$/)
              msg = ":region option must a region name, not an availability "
              msg << "zone name; try `#{matches[1]}' instead of `#{matches[0]}'"
              raise ArgumentError, msg
            end
          end
        end
      end
    end
  end
end