payrollhero / dispatch-rider / #3015

module DispatchRider

  class Subscriber

    attr_reader :queue_service_registrar, :dispatcher, :demultiplexer

    def initialize

      @queue_service_registrar = DispatchRider::Registrars::QueueService.new

      @dispatcher = DispatchRider::Dispatcher.new

    end

    def register_queue(name, options = {})

      queue_service_registrar.register(name, options)

      self

    end

    def register_handler(name)

      dispatcher.register(name)

      self

    end

    def register_handlers(*names)

      names.each {|name| register_handler(name)}

      self

    end

    def setup_demultiplexer(queue_name, error_handler = DispatchRider::DefaultErrorHandler)

      queue = queue_service_registrar.fetch(queue_name)

      @demultiplexer ||= DispatchRider::Demultiplexer.new(queue, dispatcher, error_handler)

      self

    end

    def process

      register_quit_trap

      register_term_trap

      register_int_trap

      demultiplexer.start

    end

    private

    def register_quit_trap

      Signal.trap("QUIT") do

        logger.info "Received SIGQUIT, stopping demultiplexer"

        demultiplexer.stop(reason: "Got SIGQUIT")

      end

    end

    def register_term_trap

      Signal.trap("TERM") do

        logger.info "Received SIGTERM, stopping demultiplexer"

        demultiplexer.stop(reason: "Got SIGTERM")

      end

    end

    def register_int_trap

      @already_interrupted = false

      Signal.trap("INT") do

        if @already_interrupted

          logger.info "Received SIGINT second time, aborting"

          exit(0)

        else

          logger.info "Received SIGINT first time, stopping demultiplexer"

          demultiplexer.stop(reason: "Got SIGINT")

        end

        @already_interrupted = true

      end

    end

    def logger

      DispatchRider.config.logger

    end

  end

end