package cz.cuni.amis.utils;
   
   import java.util.concurrent.TimeUnit;
   
   /**
    * This class allows you to easily setup heatup for any effect you need. I.e., something happens and you need to pursue
    * some behavior/effect for amount of time. Just create heatup with specified amount of time 
    * "for the heat" and use {@link Heatup#isHot()} to check whether you should still be using your behavior/effect.
    * <p><p>
   * To make your heatup hot, just call {@link Heatup#heat()}.
   * 
   * @author Jimmy
   */
  public class Heatup {
  
  	/**
  	 * How long is the heatup.
  	 */
  	private long heatupMillis;
  	
  	/**
  	 * When the cooldown was last used.
  	 */
  	private long lastUsedMillis;
  
  	public Heatup(long cooldownMillis) {
  		this(cooldownMillis, TimeUnit.MILLISECONDS);
  	}
  
  	public Heatup(long cooldownTime, TimeUnit timeUnit) {
  		switch(timeUnit) {
  		case DAYS: this.heatupMillis = cooldownTime * 24 * 60 * 60 * 1000; break;
  		case HOURS: this.heatupMillis = cooldownTime * 60 * 60 * 1000; break;
  		case MICROSECONDS: throw new UnsupportedOperationException("Unsupported: MICROSECONDS.");
  		case MILLISECONDS: this.heatupMillis = cooldownTime; break;
  		case MINUTES: this.heatupMillis = cooldownTime * 60 * 1000; break;
  		case NANOSECONDS:  throw new UnsupportedOperationException("Unsupported: NANOSECONDS.");
  		case SECONDS: this.heatupMillis = cooldownTime * 1000; break;
  		}
  	}
  	
  	/**
  	 * Check whether it is still hot.
  	 * @return
  	 */
  	public boolean isHot() {
  		return (System.currentTimeMillis() - lastUsedMillis < heatupMillis);
  	}
  	
  	/**
  	 * Force use of the effect == sets {@link Heatup#lastUsedMillis} to current time.
  	 */
  	public void heat() {
  		lastUsedMillis = System.currentTimeMillis();
  	}
  	
  	/**
  	 * How much time we still have until the object becomes cold, i.e., !{@link Heatup#isHot()}.
  	 * @return
  	 */
  	public long getRemainingTime() {
  		if (!isHot()) return 0;
  		return heatupMillis - (System.currentTimeMillis() - lastUsedMillis);
  	}
  
  	/**
  	 * Removes the heat...
  	 */
  	public void clear() {
  		lastUsedMillis = 0;
  	}
  
  	/**
  	 * Check whether we're cool == !{@link Heatup#isHot()}.
  	 * @return
  	 */
  	public boolean isCool() {
  		return !isHot();
  	}
  	
  }