goes_rescheduler.rb

require 'logger'
require 'time'
require 'selenium-webdriver'

# Windows version
class Rescheduler
  attr_reader :username, :password, :logger

  def initialize(username, password)
    @username, @password = 'username', 'password'
    @logger = Logger.new(STDOUT)
    logger.level = Logger::INFO
  end

  def get_body_text(browser)
    return browser.find_element(tag_name: 'body').text
  end

  def reschedule!
    browser = Selenium::WebDriver.for :chrome

    # Sign in and go to the Nexus application
    browser.navigate.to('https://goes-app.cbp.dhs.gov/main/goes')
    browser.find_element(id: 'user').send_keys(username)
    browser.find_element(id: 'password').send_keys(password)
    browser.find_element(id: 'SignIn').click
    browser.find_element(link: 'Enter').click
    browser.find_element(name: 'manageAptm').click

    # Get the current interview location and time
    body_text = get_body_text(browser)
    date = body_text[/Interview Date: (.+)/, 1]
    time = body_text[/Interview Time: (.+)/, 1]
    location = body_text[/Enrollment Center: (.+)/, 1]
    current_interview = Time.parse("#{date} #{time}")

    logger.info "Current interview: #{current_interview.strftime('%D %H:%M')} at #{location}"

    browser.find_element(name: 'reschedule').click
    browser.find_element(name: 'next').click

    # Get the interview options
    links = browser.find_elements(partial_link_text: 'Enrollment Center')
    times = get_body_text(browser).scan(/Date:(.+),\s+Start Time:(\d{2})(\d{2}),/)
                   .map {|d,h,m| Time.parse("#{d} #{h}:#{m}") }

    # Drop the time for Blaine, since there's a time for it but no link.
    times.shift

    interview_options = links.zip(times)

    logger.info "Interview options:\n#{interview_options.map {|l,d| "#{d.strftime('%D %H:%M')} at #{l.text}" }.join("\n")}"

    # Really, we only care about Seattle
    seattle = interview_options.find {|l,_| l.text.include?('Seattle') } || interview_options.first

    return if current_interview < seattle.last || !yield(seattle.last)

    logger.info "Found a better time! Switching interview to #{seattle.last.strftime('%D %H:%M')}"

    seattle.first.click
    browser.find_element(class: 'entry').click
    browser.find_element(name: 'comments').send_keys('Earlier time')
    browser.find_element(name: 'Confirm').click
  end
end

rescheduler = Rescheduler.new(ENV['GOES_USERNAME'], ENV['GOES_PASSWORD'])

while true
  rescheduler.reschedule! do |time|
    (time > Time.now + 24*60*60) # Require more than a day of warning
      # && (time.saturday? || time.sunday?) # Only a weekend
  end
  sleep 10*60 # 10 minutes
end