package test3;

/**
 * This class represents a counter.  Each counter has a count.
 * 
 * @author Franck van Breugel
 */
public class Counter 
{
    private long count;

    /**
     * Initializes this counter with the given count.
     * 
     * @param count the count of this counter.
     * @pre. count >= 0 
     */
    private Counter(long count) 
    {
	this.setCount(count);
    }

    /**
     * Returns the count of this counter.
     * 
     * @return the count of this counter.
     */
    public long getCount() 
    {
	return this.count;
    }

    /**
     * Sets the count of this counter to the given count.
     * 
     * @param count the new count of this counter.
     * @pre. count >= 0
     */
    private void setCount(long count) 
    {
	this.count = count;
    }
    
    /**
     * Increments the count of this counter.
     */
    public void increment()
    {
	this.setCount(this.getCount() + 1);
    }
    
    /**
     * Resets the counter of this counter to 0.
     */
    public void reset()
    {
	this.setCount(0);
    }
    
    /**
     * Compares this counter with the given other counter.
     * Returns a negative integer/zero/positive integer if
     * the count of this counter is smaller than/equal/greater
     * than the counter of the other counter.
     * 
     * @param other a counter.
     * @return a negative integer/zero/positive integer if
     * the count of this counter is smaller than/equal/greater
     * than the counter of the other counter.
     */
    public int compareTo(Counter other)
    {
	return (int) (this.getCount() - other.getCount());
    }
    
    /**
     * Returns a copy of the given counter if that counter is
     * not null.  Otherwise, a counter with count 0 is returned.
     * 
     * @param counter counter to be copied.
     * @return a copy of the given counter if counter != null,
     * a counter with count 0 otherwise.
     */
    public static Counter copy(Counter counter)
    {
	Counter copy;
	if (counter == null)
	{
	    copy = new Counter(0);
	}
	else
	{
	    copy = new Counter(counter.getCount());
	}
	return copy;
    }
}