notifier.rb

class Notifier
  class << self
    def build(input)
      new(
        input,
        Parser.new,
        Gateway.new
      )
    end
  end

  def initialize(input, parser, gateway)
    @input = input
    @parser = parser
    @gateway = gateway
  end

  def call
    parsed_input = parser.parse(input)
    gateway.call(parsed_input)
  end

  attr_reader :parser, :gateway, :input
end