import java.io.*;

public class DataFetcher{

	private long interval;
	private final boolean LOG = false;
	
	private JTelnet jtelnet;
	
	private SnmpGetKeyVar snmp;
	private final String ROUTER_IP = "192.168.1.1";
	private final int PORT = 161;
	private final String COMMUNITY = "public";
	// udp-in; udp-noports; icmp-inEchos; icmp-inechoReps; ip-ReasmFails
	private final String OIDS[] = {"7.1.0", "7.2.0", "5.8.0", "5.9.0", "4.16.0"};
	private SnmpData[] snmp_tmpbuf;
	private int snmp_ptr;

	private IfTrafficData[] secBuffer; //readin every 2 sec
	private IfTrafficData[] minBuffer; //readin every min
	private IfTrafficData[] hrBuffer; // readin every hour
	private int secPtr = 0;
	private int minPtr = 0;
	private int hrPtr = 0;
	private boolean flag = false;
	
	private IfTrafficData[] idf_tmpbuf;
	private int buf_ptr;
	
	private double tmp;

	long T1, T2;
	
	public DataFetcher(long interval) {
		
		this.interval = interval;

		jtelnet = new JTelnet();
		
		int i = jtelnet.initialize("\r\n", "\r\n");
		
		snmp = new SnmpGetKeyVar(ROUTER_IP, PORT, COMMUNITY, OIDS);
		snmp.init();

		if(LOG) {
			secBuffer = new IfTrafficData[60]; 
			minBuffer = new IfTrafficData[60]; 
			hrBuffer = new IfTrafficData[24];
			secPtr = 0;
			minPtr = 0;
			hrPtr = 0;
			flag = false;
		}
		else {
			clearTempBuffer();
		}

	}
	
	public SnmpData getSNMPData() {
		SnmpData sr, dif;
		sr = snmp.snmpGet();
		snmp_tmpbuf[snmp_ptr] = sr;

		if(snmp_tmpbuf[1-snmp_ptr]!=null) {
			dif = subSNMP(snmp_tmpbuf[snmp_ptr], snmp_tmpbuf[1-snmp_ptr]);
			snmp_ptr = 1 - snmp_ptr;
			return dif;
		}
		snmp_ptr = 1 - snmp_ptr;
		return null;
		
	}
	
	public SnmpData subSNMP(SnmpData cur, SnmpData old) {
		SnmpData sub = new SnmpData();
		for(int i=0; i<OIDS.length; i++) {
			sub.setOne((cur.getOne(i)-old.getOne(i)), i);
		}
		return sub;
	}
	
	public IfTrafficData fetch() {
		
		IfTrafficData pd, result;
		//IfTrafficData result;
			
		pd = jtelnet.getStats();
		//System.out.println(pd.toString());
		
		if (LOG){
			secBuffer[secPtr] = pd;
		
			if(secPtr==0) {
				if(minPtr==0) flag = true;
				minBuffer[minPtr] = pd;
				minPtr = (minPtr==59)? 0 : minPtr+1;
			}
			
			if(flag) {
				hrBuffer[hrPtr] = pd;
				hrPtr = (hrPtr==23)? 0 : hrPtr+1;
				flag = false;
			}

			secPtr++;
			if(secPtr==60){
				secPtr = 0;
				//writeLog();
			}
		}
		else {
			idf_tmpbuf[buf_ptr] = pd;
			if(idf_tmpbuf[1-buf_ptr]!=null) {
				//System.out.println("hhh");
				result = subITD(idf_tmpbuf[buf_ptr], idf_tmpbuf[1-buf_ptr]);
				buf_ptr = 1 - buf_ptr;
				return result;
			}
			buf_ptr = 1 - buf_ptr;
			return null;
		}
		return null;
	}

	public IfTrafficData subITD(IfTrafficData cur, IfTrafficData old) {
		IfTrafficData result = new IfTrafficData();
		for(int i=0; i<8; i++) {
			result.setOne((cur.getOne(i)-old.getOne(i))/(interval/1000), i);
		}
		return result;
	}
	
	public void clearTempBuffer() {
		idf_tmpbuf = new IfTrafficData[2];
		buf_ptr = 0;
		snmp_tmpbuf = new SnmpData[2];
		snmp_ptr = 0;
	}
	
	public void writeLog() {
		try {
			FileWriter out = new FileWriter("log.txt", true);
			for(int i=0; i<60; i++){
				//System.out.println("i="+i);
				out.write(secBuffer[i].toString() + "\r\n");
			}
			System.out.println("logged...");
			out.close();
		} catch (IOException e) {
		}
		//for(int i=0; i<60; i++)
			//System.out.println(secBuffer[i].toString());
	}
	
	public void close() {
		try {
			snmp.closeSession();
			jtelnet.finalise();
		} catch (Exception ex) {
			System.err.println(ex.toString());
		}
	}

}