google_contacts_connector.rb

require 'net/https'

class GoogleContactsConnector
  
  GOOGLE_AUTH_HOST = 'www.google.com'
  GOOGLE_AUTH_PORT = 443
  GOOGLE_AUTH_PATH = '/accounts/ClientLogin'
  
  CONTACTS_BASE_FEED = 'http://www.google.com/m8/feeds/contacts/default/full'
  CONTACT_GROUPS_BASE_FEED = 'http://www.google.com/m8/feeds/groups/default/full'
  
  def initialize(email, passwd)
    @email = email
    @passwd = passwd
    @token = nil
    @headers = {'Content-Type' => 'application/x-www-form-urlencoded'}
    authenticate
    @authority_group_id = get_authority_group_id if authenticated?
  end
  
  def authenticated?
    !@token.nil?
  end
  
  def find_all
    doc = REXML::Document.new(get_authority_contacts.body)
    parse_contacts_to_array(doc, "/feed/entry")
  end
  
  def find_by_entry_id(entry_id)
    doc = REXML::Document.new(get_contact(entry_id).body)
    parse_contacts_to_array(doc, "/entry")
  end
  
  private
  
  def authenticate
    http = Net::HTTP.new(GOOGLE_AUTH_HOST, GOOGLE_AUTH_PORT)
    http.use_ssl = true
    data = "accountType=HOSTED_OR_GOOGLE&Email=#{@email}&Passwd=#{@passwd}&service=cp"
    resp = http.post(GOOGLE_AUTH_PATH, data, @headers)
    if resp.code == '200'
      @token = resp.body[/Auth=(.*)/, 1]
      @headers["Authorization"] = "GoogleLogin auth=#{@token}"
      true
    else
      @token = nil
      @headers.delete("Authorization")
      false
    end
  end
  
  def get_feed(uri)
    if authenticated?
      uri = URI.parse uri
      if uri.query
        full_path = uri.path + '?' + uri.query
      else
        full_path = uri.path
      end
      Net::HTTP.start(uri.host, uri.port) do |http|
        return http.get(full_path, @headers)
      end
    end
    false
  end
  
  def get_all_groups
    uri = CONTACT_GROUPS_BASE_FEED
    get_feed uri
  end
  
  def get_authority_group_id
    doc = REXML::Document.new get_all_groups.body
    REXML::XPath.first(doc, "/feed/entry[title='author!ty']/id[1]/text()")
  end
  
  def get_authority_contacts
    uri = CONTACTS_BASE_FEED + "?group=#{@authority_group_id}&max-results=1000"
    get_feed uri
  end
  
  def get_contact(id)
    uri = CONTACTS_BASE_FEED + "/#{id}"
    get_feed uri
  end
  
  def parse_contacts_to_array(doc, xpath)
    results = {}
    doc.elements.each(xpath) do |entry|
      entry.elements.each("id[1]") do |id|
        contact_data = {}
        
        contact_data[:self_link] = entry.elements.each("link[@rel='self'][1]/@href").first.to_s
        contact_data[:name] = entry.elements.each("title[1]/text()").first.to_s
        mails = entry.elements.collect("gd:email") do |email|
          email.attributes["address"]
        end
        contact_data[:mails] = mails
        
        entry_id_uri = id.get_text.value
        contact_data[:entry_id_uri] = entry_id_uri
        id = /\/base\/(.+)/.match(entry_id_uri)[1]
        
        results[id] = contact_data
      end
    end
    results
  end
  
end