class OauthUtil

def sign( parsed_url )
  @params = {
    'oauth_consumer_key' => @consumer_key,
    'oauth_nonce' => nonce,
    'oauth_signature_method' => @sig_method,
    'oauth_timestamp' => Time.now.to_i.to_s,
    'oauth_version' => @oauth_version
  }
  # if url has query, merge key/values into params obj overwriting defaults
  if parsed_url.query
    CGI.parse( parsed_url.query ).each do |k,v|
      if v.is_a?(Array) && v.count == 1
        @params[k] = v.first
      else
        @params[k] = v
      end
    end
  end
  # @ref http://oauth.net/core/1.0/#rfc.section.9.1.2
  @req_url = parsed_url.scheme + '://' + parsed_url.host + parsed_url.path
  # create base str. make it an object attr for ez debugging
  # ref http://oauth.net/core/1.0/#anchor14
  @base_str = [ 
    @req_method, 
    percent_encode( req_url ), 
    # normalization is just x-www-form-urlencoded
    percent_encode( query_string ) 
  ].join( '&' )
  # add signature
  @params[ 'oauth_signature' ] = signature
  return self
end