require 'net/http'
require 'uri'

module Fog
  class CurrentMachine
    @@lock = Mutex.new
    AMAZON_AWS_CHECK_IP = 'http://checkip.amazonaws.com'

    def self.ip_address= ip_address
      @@lock.synchronize do
        @@ip_address = ip_address
      end
    end

    # Get the ip address of the machine from which this command is run. It is
    # recommended that you surround calls to this function with a timeout block
    # to ensure optimum performance in the case where the amazonaws checkip
    # service is unavailable.
    #
    # @example Get the current ip address
    #   begin
    #     Timeout::timeout(5) do
    #       puts "Your ip address is #{Fog::CurrentMachine.ip_address}"
    #     end
    #   rescue Timeout::Error
    #     puts "Service timeout"
    #   end
    #
    # @raise [Net::HTTPExceptions] if the net/http request fails.
    def self.ip_address
      @@lock.synchronize do
        @@ip_address ||= Net::HTTP \
          .get_response(URI.parse(AMAZON_AWS_CHECK_IP)) \
          .body.chomp
      end
    end
  end
end