album_description.rb

require 'watir-webdriver'

puts "== Album Description Updater =="
description = File.read(ARGV[0])

parts = description.scan(/https:\/\/www\.facebook\.com\/.*?\/media_set\S+/)
puts "There are #{parts.length} albums whose descriptions are to be updated!"

browser = Watir::Browser.new :firefox, :profile => 'watir'

parts.each do |part|

  album_url = if part =~ /a\.(\d+)\.\d+\.(\d+)/
                "https://m.facebook.com/#{$2}/albums/#{$1}/"
              else
                raise "Cannot generate Edit Album URL"
              end

  browser.goto album_url

  # Click the Edit link
  browser.a(href: /photos\/edit\/album/).click
  album_title = browser.input(name: 'title').value
  puts "- Updating: #{album_title}"

  # Update the description
  text = description.gsub(part) { "(this album)" }
  browser.textarea(name: 'description').value = text

  # Click the Submit button
  browser.input(type: 'submit').click

end

puts
puts "All done!"