A tiny script to import items from Instapaper to Readability

import_instapaper_to_redability.rb

#!/usr/bin/env ruby

require 'csv'
require 'net/smtp'
require 'resolv'

# We need a specific version of eventmachine due to apply a patch.
gem 'eventmachine', '0.12.10'
require 'eventmachine'

# Patch EventMachine::Protocol::SmtpClient to use HELO instead.
# Readability SMTP server doesn't understand EHLO.
# See lib/em/protocols/smtpclient.rb
module EventMachine
  module Protocols
    class SmtpClient
      def receive_signon
        return invoke_error unless @range == 2
        send_data "HELO #{@args[:domain]}\r\n"
        @responder = :receive_ehlo_response
      end
    end
  end
end

class ImportInstapaperToReadability
  MAX_URLS_IN_MAIL = 20.freeze
  DUMMY_FROM = "foo@bar".freeze

  def run!
    readability_email_address = ARGV.shift
    instapaper_csv_file = ARGV.shift

    unless readability_email_address && instapaper_csv_file
      usage
      exit
    end

    urls = parse_instapaper_csv(instapaper_csv_file)

    import_urls_to_readability(readability_email_address, urls)
  end

  private

  def usage
    puts "Usage: #{$0} <readability email address> <instapaper csv>"
  end

  def parse_instapaper_csv(path)
    CSV.read(path).map do |line|
      line[0]
    end.reverse
  end

  def import_urls_to_readability(email_address, urls)
    domain = domain_for_email_address(email_address)
    host = host_for_domain(domain)

    run_event_machine do
      urls.each_slice(MAX_URLS_IN_MAIL) do |urls_in_mail|
        puts "Importing #{urls_in_mail.size} URLs..."
        add_smtp_send({
          :verbose => true,
          :domain => domain,
          :host => host,
          :from => DUMMY_FROM,
          :to => email_address,
          :header => {:From => DUMMY_FROM, :To => email_address},
          :body => urls_in_mail.join("\r\n")
        },
        lambda {
          puts urls_in_mail.map{|url| "Imported #{url}"}
        },
        lambda {
          puts urls_in_mail.map{|url| "Failed #{url}"}
        })
      end
    end

#    Net::SMTP.start(host, 25) do |smtp|
#      urls.each_slice(MAX_URLS_IN_MAIL) do |urls_in_mail|
#        puts "Importing #{urls_in_mail.size} URLs..."
#        smtp.send_message(email_body_for_urls(DUMMY_FROM, email_address, urls_in_mail), DUMMY_FROM, email_address)
#        puts urls_in_mail.map{|url| "Imported #{url}"}
#      end
#    end
  end

  module EventMachineHelper
    def run_event_machine
      EventMachine.run do
        @count = 0
        yield
      end
    end

    def add_smtp_send(options, callback = nil, errback = nil)
      @count += 1
      EM::Protocols::SmtpClient.send(options).tap do |smtp|
        smtp.callback do
          callback.call if callback
          stop_event_machine_if_last_job
        end
        smtp.errback do
          errback.call if errback
          stop_event_machine_if_last_job
        end
      end
    end

    def stop_event_machine_if_last_job
      @count -= 1
      EventMachine.stop unless @count > 0
    end
  end
  include EventMachineHelper

  def domain_for_email_address(email_address)
    $1 if /@([^@]+)$/ === email_address
  end

  def host_for_domain(domain)
    resource = Resolv::DNS.new.getresource(domain, Resolv::DNS::Resource::IN::MX)
    if Resolv::DNS::Resource::IN::MX === resource
      resource.exchange.to_s
    end
  end

#  def email_body_for_urls(from, to, urls)
#    <<-END_OF_EMAIL
#From: <#{from}>
#To: <#{to}>
#
##{urls.join("\r\n")}
#    END_OF_EMAIL
#  end
end

ImportInstapaperToReadability.new.run!