require 'custodian/util/dns'



#
# This class has methods to determine whether the target
# of a hostname/IP address is IPv4 or IPv6.
#
# Assuming the address resolves to one of those two types
# it can invoke on of /usr/bin/ping or /usr/bin/ping6 appropriately.
#
module Custodian

  module Util

    class Ping

      #
      # The hostname we'll ping, and the resolved address.
      #
      attr_reader :hostname, :resolved

      #
      # Save the hostname away, resolve it if possible.
      #
      def initialize(hostname)

        raise ArgumentError, 'Hostname must not be nil' if hostname.nil?
        raise ArgumentError, 'Hostname must be a String' unless hostname.kind_of?(String)

        @hostname = hostname
        @resolved = Custodian::Util::DNS.hostname_to_ip(hostname)
      end


      #
      # Return the resolved address
      #
      def address
        @resolved
      end

      #
      # Does the hostname resolve to an IPv4 address?
      #
      def is_ipv4?
        if (! @resolved.nil?) && (@resolved =~ /^([0-9]+).([0-9]+).([0-9]+).([0-9]+)$/)
          true
        else
          false
        end
      end


      #
      # Does the hostname resolve to an IPv6 address?
      #
      def is_ipv6?
        if (! @resolved.nil?) && (@resolved =~ /^([a-f0-9:]+)$/i)
          true
        else
          false
        end
      end



      #
      # Run the ping - if it succeeds return "true".
      #
      # Return false on error.
      #
      def run_ping
        if is_ipv6?
          if (system("ping6 -c 1 #{@resolved} 2>/dev/null >/dev/null") == true)
            return true
          end
        elsif is_ipv4?
          if (system("ping -c 1 #{@resolved} 2>/dev/null >/dev/null") == true)
            return true
          end
        else
          puts 'ERROR: Resolved to neither an IPv6 or IPv4 address.'
        end
        false
      end

    end

  end
end