package org.itx.jspwiki.plugin.snmp;

import java.util.Map;
import java.util.Observable;
import java.util.Observer;

import com.ecyrd.jspwiki.WikiContext;
import com.ecyrd.jspwiki.plugin.PluginException;
import com.ecyrd.jspwiki.plugin.WikiPlugin;

import uk.co.westhawk.snmp.stack.AsnObject;
import uk.co.westhawk.snmp.stack.GetPdu;
import uk.co.westhawk.snmp.stack.Pdu;
import uk.co.westhawk.snmp.stack.PduException;
import uk.co.westhawk.snmp.stack.SnmpContext;
import uk.co.westhawk.snmp.stack.varbind;

public class SnmpStatus implements WikiPlugin {

	protected class Receiver implements Observer {
		varbind[] vars = null;

		public void update(Observable obs, Object arg) {
			GetPdu pdu = (GetPdu) obs;
			if (pdu.getErrorStatus() == AsnObject.SNMP_ERR_NOERROR) {
				try {
					vars = pdu.getResponseVarbinds();
				} catch (PduException e) {
					e.printStackTrace();
				}
			} else {
				destroyAll(pdu);
				return;
			}
		}

	}

	
	
	@SuppressWarnings("unchecked")
	public String execute(WikiContext context, Map params)
			throws PluginException {

		SnmpContext snmpcontext;
		GetPdu pdu = null;
		Receiver receiver;
		StringBuffer out = new StringBuffer();
		
		String host = getStringParameter(params,"host","127.0.0.1");
		String port = getStringParameter(params,"port","161");
		String comm = getStringParameter(params,"comm","public");
		String oid = getStringParameter(params,"oid","1.3.6.1.2.1.1.1.0");
		String nonvalue = getStringParameter(params,"nonvalue","service not available");

		try {
			snmpcontext = createContext(host, Integer.parseInt(port), "udp", comm);
			receiver = new Receiver();
			pdu = createPdu(snmpcontext, new varbind(oid), receiver);
			pdu.send();
		} catch (java.io.IOException exc) {
			destroyAll(pdu);
			return out.toString();
		} catch (uk.co.westhawk.snmp.stack.PduException exc) {
			destroyAll(pdu);
			return out.toString();
		}
		
		for(int i=0;(i<100) && (receiver.vars == null);i++)
			try {
				System.out.println("Wait for ");
				Thread.sleep(10);
			} catch (InterruptedException e) {
			}
		if (receiver.vars != null)
			for (varbind v : receiver.vars) {
				out.append(v.getValue()); 
			}
		else
			out.append(nonvalue);

		destroyAll(pdu);
		return out.toString();
	}

	private synchronized void destroyAll(Pdu pdu) {
		if (pdu == null) {
			System.out.println("Strange destroy!!!");
			return;
		}
		pdu.deleteObservers();
		pdu.getContext().destroy();
	}

	@SuppressWarnings("unchecked")
	private String getStringParameter(Map params, String str,
			String def) {
		String value = (String) params.get(str);
		if (value == null) {
			value = def;
		}
		return value;
	}


	protected SnmpContext createContext(String host, int port,
			String socketType, String community) throws java.io.IOException {
		SnmpContext con = new SnmpContext(host, port, socketType);
		con.setCommunity(community);
		return con;
	}

	protected GetPdu createPdu(SnmpContext snmpcontext, varbind var, Observer obs) {
		GetPdu newPdu = new GetPdu(snmpcontext);
		newPdu.addOid(var);
		newPdu.addObserver(obs);
		return newPdu;
	}

}