/*
 *  This file is part of the Jikes RVM project (http://jikesrvm.org).
 *
 *  This file is licensed to You under the Eclipse Public License (EPL);
 *  You may not use this file except in compliance with the License. You
 *  may obtain a copy of the License at
 *
 *      http://www.opensource.org/licenses/eclipse-1.0.php
 *
 *  See the COPYRIGHT.txt file distributed with this work for information
 *  regarding copyright ownership.
 */
package org.jikesrvm.tools.ant;

import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.Task;
import org.apache.tools.ant.taskdefs.Property;

/**
 * Timer task makes it possible to measure the start, stop and duration between two points in time.
 *
 * When the task is run with stop set to fals or not yet specified the task stores
 * the current time in a property with the name "<property>.start". If stop is set to
 * true then the task attempts to load a start time from "<property>.start" and then
 * stores the current time in "<property>.end" and the duration between "<property>.start"
 * and now in "<property>.duration".
 */
public class TimerTask
    extends Task {
  private String property;
  private boolean stop;

  public void setProperty(final String property) {
    this.property = property;
  }

  public void setStop(final boolean stop) {
    this.stop = stop;
  }

  public void execute() throws BuildException {
    if (null == property) throw new BuildException("Property not set.");
    final long now = System.currentTimeMillis();
    if (stop) {
      final String start = getProject().getProperty(property + ".start");
      if (null == start) throw new BuildException("Start not yet set.");
      final long startTime = Long.parseLong(start);
      setProperty(property + ".end", String.valueOf(now));
      setProperty(property + ".duration", String.valueOf(Math.abs(now - startTime)));
    } else {
      setProperty(property + ".start", String.valueOf(now));
    }
  }

  private void setProperty(final String name, final String value) {
    final Property property = (Property) getProject().createTask("property");
    property.setOwningTarget(getOwningTarget());
    property.init();
    property.setName(name);
    property.setValue(value);
    property.execute();
  }
}