/*
 ***************************************************************************************
 *  Copyright (C) 2006 EsperTech, Inc. All rights reserved.                            *
 *  http://www.espertech.com/esper                                                     *
 *  http://www.espertech.com                                                           *
 *  ---------------------------------------------------------------------------------- *
 *  The software in this package is published under the terms of the GPL license       *
 *  a copy of which has been included with this distribution in the license.txt file.  *
 ***************************************************************************************
 */
package com.espertech.esper.example.stockticker;

import com.espertech.esper.client.EPRuntime;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Utility methods for monitoring a EPRuntime instance.
 */
public class EPRuntimeUtil {
    public static boolean awaitCompletion(EPRuntime epRuntime,
                                          int numEventsExpected,
                                          int numSecAwait,
                                          int numSecThreadSleep,
                                          int numSecThreadReport) {
        log.info(".awaitCompletion Waiting for completion, expecting " + numEventsExpected +
                " events within " + numSecAwait + " sec");

        int secondsWaitTotal = numSecAwait;
        long lastNumEventsProcessed = 0;
        int secondsUntilReport = 0;

        long startTimeMSec = System.currentTimeMillis();
        long endTimeMSec = 0;

        while (secondsWaitTotal > 0) {
            try {
                Thread.sleep(numSecThreadSleep * 1000);
            } catch (InterruptedException ex) {
            }

            secondsWaitTotal -= numSecThreadSleep;
            secondsUntilReport += numSecThreadSleep;
            long currNumEventsProcessed = epRuntime.getNumEventsEvaluated();

            if (secondsUntilReport > numSecThreadReport) {
                long numPerSec = (currNumEventsProcessed - lastNumEventsProcessed) / numSecThreadReport;
                log.info(".awaitCompletion received=" + epRuntime.getNumEventsEvaluated() +
                        "  processed=" + currNumEventsProcessed +
                        "  perSec=" + numPerSec);
                lastNumEventsProcessed = currNumEventsProcessed;
                secondsUntilReport = 0;
            }

            // Completed loop if the total event count has been reached
            if (epRuntime.getNumEventsEvaluated() == numEventsExpected) {
                endTimeMSec = System.currentTimeMillis();
                break;
            }
        }

        if (endTimeMSec == 0) {
            log.info(".awaitCompletion Not completed within " + numSecAwait + " seconds");
            return false;
        }

        long totalUnitsProcessed = epRuntime.getNumEventsEvaluated();
        long deltaTimeSec = (endTimeMSec - startTimeMSec) / 1000;

        long numPerSec = 0;
        if (deltaTimeSec > 0) {
            numPerSec = (totalUnitsProcessed) / deltaTimeSec;
        } else {
            numPerSec = -1;
        }

        log.info(".awaitCompletion Completed, sec=" + deltaTimeSec + "  avgPerSec=" + numPerSec);

        long numReceived = epRuntime.getNumEventsEvaluated();
        long numReceivedPerSec = 0;
        if (deltaTimeSec > 0) {
            numReceivedPerSec = (numReceived) / deltaTimeSec;
        } else {
            numReceivedPerSec = -1;
        }

        log.info(".awaitCompletion Runtime reports, numReceived=" + numReceived +
                "  numProcessed=" + epRuntime.getNumEventsEvaluated() +
                "  perSec=" + numReceivedPerSec
        );

        return true;
    }

    private static final Logger log = LoggerFactory.getLogger(EPRuntimeUtil.class);
}