/* I represent a waterway, e.g. a river, creak, or a stream
 * En Å, bæk eller grøft
 */
public class WaterWay {
	private String name;
	private double length; // - in kilometers
	private WaterSource source;

	private WaterWay[] tributaries = new WaterWay[20]; // Max 20 tributaries
	private int numberOfTributaries = 0; 

	public WaterWay(String name, double length, WaterSource source){
		this.name   = name;
		this.length = length;
		this.source = source;
	}
	/* accessor */
	public int getNumberOfTributaries(){
		return numberOfTributaries;
	}
	/* indexed accessor */
	public WaterWay getTributary(int index){
		return tributaries[index];
	}
	/* accessor */
	public WaterSource getSource(){
		return source;
	}
	
	/* Add a tributary to this waterway. A max of 20 can be added */
	public void addTributary(WaterWay ww){
		tributaries[numberOfTributaries] = ww;
		numberOfTributaries++;
	}

	/* Return the total length og this waterway and all its tributaries */
	public double totalLength(){
		double totalLength = this.length;
		for (int index = 0; index<numberOfTributaries; index++)
			totalLength = totalLength 
				+ tributaries[index].totalLength();
		return totalLength;
	}
	/* Return the total waterPrHour for the waterway given as parameter.
	 * Notice, this is a static method, to illustrate recursion with the outset
	 * in a parameter.
	 */
    public static double totalLitersPrHour(WaterWay ww){
		double total = ww.getSource().getLitersPrHour();
		for (int index = 0; index < ww.getNumberOfTributaries(); index++)
			total = total + totalLitersPrHour( ww.getTributary(index) );
		return total;
	}
}