/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.hadoop.yarn.server.applicationhistoryservice.metrics
  .loadsimulator;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

/**
 * Sample Usage:
 * <pre>
 * $ java -cp "dependency/*":LoadSimulator-1.0-SNAPSHOT.jar \
 * org.apache.ambari.metrics.MetricsLoadSimulator \
 * -h "bartosz.laptop" -n 2 -m "162.216.148.45" -c 10000 -s 30000</pre>
 */
public class MetricsLoadSimulator {
  private final static Logger LOG = LoggerFactory.getLogger(MetricsLoadSimulator
    .class);

  public static void main(String[] args) throws IOException, InterruptedException {
    Map<String, String> mapArgs = parseArgs(args);

    LoadRunner loadRunner = new LoadRunner(
      mapArgs.get("hostName"),
      Integer.valueOf(mapArgs.get("numberOfHosts")),
      mapArgs.get("metricsHostName"),
      Integer.valueOf(mapArgs.get("collectInterval")),
      Integer.valueOf(mapArgs.get("sendInterval")),
      Boolean.valueOf(mapArgs.get("master"))
    );

    loadRunner.start();
  }

  private static Map<String, String> parseArgs(String[] args) {
    Map<String, String> mapProps = new HashMap<String, String>();
    mapProps.put("hostName", "host");
    mapProps.put("numberOfHosts", "20");
    mapProps.put("trafficType", "burst");
    mapProps.put("metricsHostName", "localhost");
    mapProps.put("collectInterval", "10000");
    mapProps.put("sendInterval", "60000");

    if (args.length == 0) {
      printUsage();
      throw new RuntimeException("Unexpected argument, See usage message.");
    } else {
      for (int i = 0; i < args.length; i += 2) {
        String arg = args[i];
        if (arg.equals("-h")) {
          mapProps.put("hostName", args[i + 1]);
        } else if (arg.equals("-n")) {
          mapProps.put("numberOfHosts", args[i + 1]);
        } else if (arg.equals("-t")) {
          mapProps.put("trafficType", args[i + 1]);
        } else if (arg.equals("-m")) {
          mapProps.put("metricsHostName", args[i + 1]);
        } else if (arg.equals("-c")) {
          mapProps.put("collectInterval", args[i + 1]);
        } else if (arg.equals("-s")) {
          mapProps.put("sendInterval", args[i + 1]);
        } else if (arg.equals("-M")) {
          mapProps.put("master", args[i + 1]);
        } else if (arg.equals("-d")) {
          // a dummy switch - it says that we agree with defaults
        } else {
          printUsage();
          throw new RuntimeException("Unexpected argument, See usage message.");
        }
      }
    }

    LOG.info("Recognized options: baseHostName={} hosts#={} trafficMode={} " +
        "metricsHostName={} collectIntervalMillis={} sendIntervalMillis={} " +
        "simulateMaster={}",
      mapProps.get("hostName"),
      Integer.valueOf(mapProps.get("numberOfHosts")),
      mapProps.get("trafficType"),
      mapProps.get("metricsHostName"),
      Integer.valueOf(mapProps.get("collectInterval")),
      Integer.valueOf(mapProps.get("sendInterval")),
      Boolean.valueOf(mapProps.get("master"))
    );

    return mapProps;
  }

  public static void printUsage() {
    System.err.println("Usage: java MetricsLoadSimulator [OPTIONS]");
    System.err.println("Options: ");
    System.err.println("[-h hostName] [-n numberOfHosts] "
      + "[-t trafficMode {burst, staggered}] [-m metricsHostName] "
      + "[-c collectIntervalMillis {10 sec}] [-s sendIntervalMillis {60 sec}]"
      + "[-M simulateMaster {true, false}] ");
    System.err.println();
    System.err.println("When you select a master, then one simulated host will play");
    System.err.println("a role of a master, and the rest will be slaves. Otherwise");
    System.err.println("all simulation threads (single thread is for single host)");
    System.err.println("will be slave hosts");
  }
}
