module BBQueue
  class Consumer
    attr_accessor :logger

    def before_fork
      # Nothing
    end

    def after_fork
      # Nothing
    end

    def fork?
      false
    end

    def fork_and_wait
      if fork?
        before_fork

        Process.fork do
          after_fork

          yield
        end

        Process.wait
      else
        yield
      end
    end

    def work(job, queue_name)
      fork_and_wait do
        begin
          job.work
        rescue Timeout::Error, StandardError => e
          logger.error "Job #{job.inspect} on #{queue_name.inspect} failed"
          logger.error e
        end
      end
    end

    def initialize(queue_names, options = {})
      self.logger = logger = options[:logger] || BBQueue::NullLogger.new

      consumer = self

      Stalking::Consumer.new options.merge(:logger => BBQueue::FatalLogger.new(logger)) do
        Array(queue_names).each do |queue_name|
          job queue_name do |args|
            consumer.work BBQueue::Serializer.load(args["object"]), queue_name
          end
        end

        before do |queue_name, args|
          logger.info "Job #{BBQueue::Serializer.load(args["object"]).inspect} on #{queue_name.inspect} started"
        end

        after do |queue_name, args|
          logger.info "Job #{BBQueue::Serializer.load(args["object"]).inspect} on #{queue_name.inspect} finished"
        end

        error do |e, queue_name, args|
          logger.error "Job #{BBQueue::Serializer.load(args["object"]).inspect} on #{queue_name.inspect} failed"
          logger.error e
        end
      end
    end
  end
end