Add trackable links

trackable_links.rb

# ruby script/trackable_links.rb script/a.txt "?a=2&c=3"

require 'addressable/uri'
require 'nokogiri'

class TrackableLinks
  ALLOWED_SCHEMAS = %w(http https)

  class << self
    def add(body, options)
      doc = Nokogiri::HTML(body)

      doc.css("a[href]").each do |link|
        uri = parse_uri(link["href"])

        next unless trackable_uri?(uri)

        params = uri.query_values || {}
        options.each do |key, value|
          params[key] ||= value
        end
        uri.query_values = params
        link["href"] = uri.to_s
      end

      doc.to_s
    end

    private

    def trackable_uri?(uri)
      uri && uri.absolute? && ALLOWED_SCHEMAS.include?(uri.scheme)
    end

    def parse_uri(href)
      Addressable::URI.parse(href.to_s) rescue nil
    end
  end
end
options = Addressable::URI.parse(ARGV[1]).query_values
html = TrackableLinks.add(File.open(ARGV[0]).read, options)
File.open(ARGV[0], 'w').puts(html)