/*
 *
 *  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.metron.profiler.clock;

import org.apache.metron.common.configuration.profiler.ProfilerConfig;

import java.io.Serializable;

/**
 * Creates a {@link Clock} based on the profiler configuration.
 *
 * <p>If the Profiler is configured to use event time, a {@link EventTimeClock} will
 * be created.  Otherwise, a {@link WallClock} will be created.
 *
 * <p>The default implementation of a {@link ClockFactory}.
 */
public class DefaultClockFactory implements ClockFactory, Serializable {

  /**
   * @param config The profiler configuration.
   * @return The appropriate Clock based on the profiler configuration.
   */
  @Override
  public Clock createClock(ProfilerConfig config) {
    Clock clock;

    boolean isEventTime = config.getTimestampField().isPresent();
    if(isEventTime) {

      // using event time
      String timestampField = config.getTimestampField().get();
      clock = new EventTimeClock(timestampField);

    } else {

      // using processing time
      clock = new WallClock();
    }

    return clock;
  }
}
