goes_rescheduler.rb

require 'logger'
require 'time'

require 'dotenv'
require 'pry'
require 'watir-webdriver'

Dotenv.load

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 reschedule!
    browser = Watir::Browser.new :phantomjs

    # Sign in and go to the Nexus application
    browser.goto('https://goes-app.cbp.dhs.gov/main/goes')
    browser.text_field(id: 'user').set(username)
    browser.text_field(id: 'password').set(password)
    browser.button(id: 'SignIn').click
    browser.link(text: 'Enter').click
    browser.button(value: 'Manage Interview Appointment').click

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

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

    browser.button(value: 'Reschedule Appointment').click
    browser.button(value: 'Next').click

    # Get the interview options
    links = browser.links(href: /javascript:scheduleInterview\('\d+'\)/)
    times = browser.text.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.link(class: 'entry').click
    browser.text_field(name: 'comments').set('Better time')
    browser.button(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