package com.sitech.ismp.util;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Vector;

import org.snmp4j.CommunityTarget;
import org.snmp4j.PDU;
import org.snmp4j.Snmp;
import org.snmp4j.TransportMapping;
import org.snmp4j.event.ResponseEvent;
import org.snmp4j.mp.SnmpConstants;
import org.snmp4j.smi.Address;
import org.snmp4j.smi.GenericAddress;
import org.snmp4j.smi.OID;
import org.snmp4j.smi.OctetString;
import org.snmp4j.smi.VariableBinding;
import org.snmp4j.transport.DefaultUdpTransportMapping;

/**
 * ClassName:SnmpHandler
 * Description: SNMP工具类
 *
 * @author   Linxc
 * @version  
 * @since    Ver 1.1
 * @Date	 2012	Feb 28, 2012		5:19:22 PM
 */
public class SnmpHandler {
	private String ipAddr;
	private int port;
	private String community;
	private int version;
	
	
	private Snmp snmp = null;   
	 private Address targetAddress = null;
	private CommunityTarget target = null;

	public SnmpHandler(String ipAddr, int port, String community, int version) throws Exception {		
		this.ipAddr = ipAddr;
		this.port = port;
		this.community = community;
		this.version = version;

		init();
	}

	@SuppressWarnings("unchecked")
	public String get(String oid) {
		PDU pdu = new PDU();
		pdu.add(new VariableBinding(new OID(oid)));
		pdu.setType(PDU.GET);

		try {
			ResponseEvent respEvnt = snmp.send(pdu, target);
			if (respEvnt != null && respEvnt.getResponse() != null) {
				Vector<VariableBinding> recVBs = respEvnt.getResponse().getVariableBindings();
				if (recVBs.size() > 0) {
					VariableBinding recVB = recVBs.elementAt(0);
					return recVB.getVariable().toString();
				}
			}
		} catch (IOException e) {
			e.printStackTrace();
		}
		return null;
	}

	public String getNext(String oid) {
		return null;
	}

	@SuppressWarnings("unchecked")
	public List<String> walk(String sOid) {
		if(sOid.startsWith(".")){
			sOid = sOid.substring(1, sOid.length());
		}
		List<String> result = new ArrayList<String>();
		
		try {
			OID oid = new OID(sOid);
			for(int i=0; i<3000; i++) {
				PDU pdu = new PDU();
				pdu.add(new VariableBinding(oid));
				pdu.setType(PDU.GETNEXT);
				
				ResponseEvent respEvnt = snmp.send(pdu, target);
				if (respEvnt != null && respEvnt.getResponse() != null) {
					Vector<VariableBinding> recVBs = respEvnt.getResponse()
							.getVariableBindings();
					if (recVBs !=null && recVBs.size() > 0) {
						VariableBinding recVB = recVBs.elementAt(0);

						oid = recVB.getOid();
						
						String sRecOid = oid.toString();
						if(sRecOid.substring(0, sRecOid.lastIndexOf(".")).equals(sOid)){
							result.add(recVB.getVariable().toString());
							System.out.println(sRecOid + "\t " + recVB.getVariable().toString());
						}else{
							break;
						}

					}else{
						break;
					}
				}
			}
		} catch (IOException e) {
			e.printStackTrace();
		}
		return result;
	}
	
	public void init() throws IOException {
		targetAddress = GenericAddress.parse("udp:" + ipAddr + "/" + port + "");
		;
		TransportMapping transport = new DefaultUdpTransportMapping();
		snmp = new Snmp(transport);
		transport.listen();

		target = new CommunityTarget();
		target.setCommunity(new OctetString(community));
		target.setAddress(targetAddress);
		target.setRetries(2);
		target.setTimeout(1500);
		switch (version) {
		case 1:
			target.setVersion(SnmpConstants.version1);
			break;
		case 2:
			target.setVersion(SnmpConstants.version2c);
			break;
		case 3:
			// 暂时不支持V3版本
			target.setVersion(SnmpConstants.version3);
			break;
		default:
			break;
		}
	}
	
	public void destroy() {
		if (snmp != null) {
			try {
				snmp.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
	}
	
	public static void main(String[] args) throws Exception {
		
//		System.out.println();
//		new SnmpHandler("172.21.0.253",161,"public",1).get(".1.3.6.1.4.1.9.2.1.57.0");
		new SnmpHandler("172.21.0.253",161,"public",1).walk(".1.3.6.1.4.1.9.9.48.1.1.1.5");
	}
}