using System;
using ln.snmp.types;
using System.Net;
using System.Collections.Generic;

namespace ln.snmp.channel
{
    public class SnmpV1Channel : SnmpPDUChannel
    {
        public override SnmpVersion SnmpVersion => SnmpVersion.V1;

        public OctetString CommunityString { get; set; }


        public SnmpV1Channel(SNMPEngine client)
            :base(client)
        {
            CommunityString = "public";
        }
        public SnmpV1Channel(SNMPEngine client,string communityString)
            :base(client)
        {
            CommunityString = communityString;
        }

        public override PDU RequestResponse(PDU pdu,IPEndPoint remoteEndpoint)
        {
            Integer version = new Integer((int)SnmpVersion);

            Sequence snmpRequest = new Sequence();
            snmpRequest.Add(version);
            snmpRequest.Add(CommunityString);
            snmpRequest.Add(pdu);

            Variable reply = SNMPClient.SNMPRequest(remoteEndpoint, snmpRequest);

            Sequence sreply = reply as Sequence;
            PDU responsePDU = sreply.Items[2] as PDU;

            if (responsePDU.Error.LongValue != 0)
            {
                string indicator = responsePDU.ErrorIndex > 0 && responsePDU.ErrorIndex  <= pdu.VarBinds.Items.Length ? ((pdu.VarBinds.Items[(int)responsePDU.ErrorIndex - 1] as Sequence).Items[0] as ObjectIdentifier).AsString : "";
                throw new SnmpError(responsePDU.Error, responsePDU.ErrorIndex, indicator);
            }

            return responsePDU;
        }
    }
}