using System.Net.Sockets;
using System.Runtime.InteropServices;

namespace System.Net.NetworkInformation
{
    
    public class PingReply
    {
        IPAddress address;
        PingOptions options;
        IPStatus ipStatus;  // the status code returned by icmpsendecho, or the icmp status field on the raw socket
        long rtt;  // the round trip time.
        byte[] buffer; //buffer of the data


        internal PingReply(){
        }

        internal PingReply (IPStatus ipStatus) {
            this.ipStatus = ipStatus;
            buffer = new byte[0];
        }

        // The downlevel constructor. 
        internal PingReply (byte[] data, int dataLength, IPAddress address, int time) {
            this.address = address;
            rtt = time;


            ipStatus = GetIPStatus ((IcmpV4Type)data[20],(IcmpV4Code) data[21]);

            if (ipStatus == IPStatus.Success) {
                buffer = new byte[dataLength - 28];
                Array.Copy (data, 28, buffer, 0, dataLength - 28);
            }
            else
                buffer = new byte[0];
        }


        // the main constructor for the icmpsendecho apis
        internal PingReply (IcmpEchoReply reply) {
            address = new IPAddress (reply.address);
            ipStatus = (IPStatus)reply.status; //the icmpsendecho ip status codes

            //only copy the data if we succeed w/ the ping operation
            if (ipStatus == IPStatus.Success) {
                rtt = (long)reply.roundTripTime;
                buffer = new byte[reply.dataSize];
                Marshal.Copy (reply.data, buffer, 0, reply.dataSize);
                options = new PingOptions (reply.options);
            }
            else
                buffer = new byte[0];

        }

                // the main constructor for the icmpsendecho apis
        internal PingReply (Icmp6EchoReply reply, IntPtr dataPtr, int sendSize) {
            
            address = new IPAddress(reply.Address.Address,reply.Address.ScopeID);
            ipStatus = (IPStatus)reply.Status; //the icmpsendecho ip status codes

            //only copy the data if we succeed w/ the ping operation
            if (ipStatus == IPStatus.Success) {
                rtt = (long)reply.RoundTripTime;
                buffer = new byte[sendSize];
                Marshal.Copy (IntPtrHelper.Add(dataPtr, 36), buffer, 0, sendSize);
                //options = new PingOptions (reply.options);
            }
            else
                buffer = new byte[0];

        }


 
        //translates the relevant icmpsendecho codes to a ipstatus code
        private IPStatus GetIPStatus (IcmpV4Type type, IcmpV4Code code) {
            switch (type) {
                case IcmpV4Type.ICMP4_ECHO_REPLY:
                    return IPStatus.Success;
                case IcmpV4Type.ICMP4_SOURCE_QUENCH:
                    return IPStatus.SourceQuench;
                case IcmpV4Type.ICMP4_PARAM_PROB:
                    return IPStatus.ParameterProblem;
                case IcmpV4Type.ICMP4_TIME_EXCEEDED:
                   return IPStatus.TtlExpired;

                case IcmpV4Type.ICMP4_DST_UNREACH:
                {
                    switch (code) {
                        case  IcmpV4Code.ICMP4_UNREACH_NET:
                            return IPStatus.DestinationNetworkUnreachable;
                        case  IcmpV4Code.ICMP4_UNREACH_HOST:
                            return IPStatus.DestinationHostUnreachable;
                        case  IcmpV4Code.ICMP4_UNREACH_PROTOCOL:
                            return IPStatus.DestinationProtocolUnreachable;
                        case  IcmpV4Code.ICMP4_UNREACH_PORT:
                            return IPStatus.DestinationPortUnreachable;
                        case  IcmpV4Code.ICMP4_UNREACH_FRAG_NEEDED:
                            return IPStatus.PacketTooBig;
                        default:
                            return IPStatus.DestinationUnreachable;
                    }
                }
            }
            return IPStatus.Unknown;
        }

        //the basic properties
        public IPStatus Status { get { return ipStatus; } }
        public IPAddress Address { get { return address; } }
        public long RoundtripTime { get { return rtt; } }
        public PingOptions Options { 
            get {
                return options; 
            } 
        }
        public byte[] Buffer { get { return buffer; } }
    }
}