package cz.cuni.amis.utils;
   
   import java.util.concurrent.TimeUnit;
   
   /**
    * This class allows you to easily setup cooldown for any effect you need. Just create cooldown with specified amount of time 
    * "for the cooldown" and use {@link Cooldown#tryUse()} to check whether you may use your effect now.
    * <p><p>
    * Opposite functionality (doing something until some time passes by) is captured by {@link Heatup}.
   * 
   * @author Jimmy
   */
  /**
   * @author Jimmy
   *
   */
  public class Cooldown {
  
  	/**
  	 * How long is the cooldown.
  	 */
  	private long cooldownMillis;
  	
  	/**
  	 * When the cooldown was last used.
  	 */
  	private long lastUsedMillis;
  
  	public Cooldown(long cooldownMillis) {
  		this(cooldownMillis, TimeUnit.MILLISECONDS);
  	}
  
  	public Cooldown(long cooldownTime, TimeUnit timeUnit) {
  		switch(timeUnit) {
  		case DAYS: this.cooldownMillis = cooldownTime * 24 * 60 * 60 * 1000; break;
  		case HOURS: this.cooldownMillis = cooldownTime * 60 * 60 * 1000; break;
  		case MICROSECONDS: throw new UnsupportedOperationException("Unsupported: MICROSECONDS.");
  		case MILLISECONDS: this.cooldownMillis = cooldownTime; break;
  		case MINUTES: this.cooldownMillis = cooldownTime * 60 * 1000; break;
  		case NANOSECONDS:  throw new UnsupportedOperationException("Unsupported: NANOSECONDS.");
  		case SECONDS: this.cooldownMillis = cooldownTime * 1000; break;
  		}
  	}
  	
  	/**
  	 * Check whether it is {@link Cooldown#isCool()}, if so, save current time as the time of the use and returns true,
  	 * otherwise (== effect needs more cooldown, see {@link Cooldown#getRemainingTime()}) returns false.
  	 * @return
  	 */
  	public boolean tryUse() {
  		long time = System.currentTimeMillis();
  		if (time - lastUsedMillis >= cooldownMillis) {
  			this.lastUsedMillis = time;
  			return true;
  		}
  		return false;
  	}
  	
  	/**
  	 * Force use of the effect == sets {@link Cooldown#lastUsedMillis} to current time.
  	 */
  	public void use() {
  		lastUsedMillis = System.currentTimeMillis();
  	}
  	
  	/**
  	 * Whether you may use the effect, i.e., it was never used before or has cooled down.
  	 * @return
  	 */
  	public boolean isCool() {
  		return (System.currentTimeMillis() - lastUsedMillis >= cooldownMillis);
  	}
  	
  	/**
  	 * Whether we're not {@link Cooldown#isCool()}.
  	 */
  	public boolean isHot() {
  		return !isCool();
  	}
  	
  	/**
  	 * How much time we need to wait before the effect will cool down.
  	 * @return
  	 */
  	public long getRemainingTime() {
  		if (isCool()) return 0;
  		return cooldownMillis - (System.currentTimeMillis() - lastUsedMillis);
  	}
  	
  	/**
  	 * Cools down totally.
  	 */
  	public void clear() {
  		lastUsedMillis = 0;
  	}
  	
  }