Long URL finder

long_url.rb

# Long URL finder
# Copyright 2011 Jonathan Rudenberg
# Licensed under the MIT License
#
# Usage:
# LongURL.find('http://t.co/tssMTwK') #=> "http://fuckyeahnouns.com/Bacon"

require 'net/http'
require 'uri'

class LongURL

  REDIRECT_CODES = %w(300 301 302 303)
  MAX_REDIRECTS = 5

  attr_accessor :short_urls

  def self.find(short_url)
    new(short_url).find
  end

  def initialize(short_url)
    @short_urls = []
    @url = short_url
  end

  def find(uri = nil)
    uri ||= @url

    url = URI.parse(uri)
    http = Net::HTTP.new(url.host, url.port)
    http.use_ssl = true if url.scheme == 'https'
    response = http.request_head url.path.empty? ? '/' : url.path

    if REDIRECT_CODES.include?(response.code)
      @short_urls << uri
      return uri if @short_urls.length > MAX_REDIRECTS
      find(response['Location'])
    else
      return uri
    end
  rescue
    return @url
  end

end