/*
 * PageRank.java
 *
 * Created on den 9 oktober 2002, 14:33
 */
import java.util.*;
/**
 *
 * @author  h&m
 */
public class PageRank {
    private Collection pages = new Vector();
    private boolean printIterations;
    private int iterations = 0;
    
    /** Creates a new instance of PageRank */
    public PageRank(boolean pi) {
        printIterations = pi;
    }
    
    public void addPage(Page p) {
        pages.add(p);
    }
    
    public PageRank addPages(Collection pages) {
        this.pages = pages;
        return this;
    }
    
    /** Returns a string representation of the object. In general, the
     * <code>toString</code> method returns a string that
     * "textually represents" this object. The result should
     * be a concise but informative representation that is easy for a
     * person to read.
     * It is recommended that all subclasses override this method.
     * <p>
     * The <code>toString</code> method for class <code>Object</code>
     * returns a string consisting of the name of the class of which the
     * object is an instance, the at-sign character `<code>@</code>', and
     * the unsigned hexadecimal representation of the hash code of the
     * object. In other words, this method returns a string equal to the
     * value of:
     * <blockquote>
     * <pre>
     * getClass().getName() + '@' + Integer.toHexString(hashCode())
     * </pre></blockquote>
     *
     * @return  a string representation of the object.
     *
     */
    public String toString() {
        String tmp = new String();
        Iterator iter = pages.iterator();
        while(iter.hasNext())
            tmp += ((Page) iter.next()).toString() + "  ";
        return tmp;
    }
    
    public int getIterations() {
        return iterations;
    }
    
    public void calculatePR() {
        boolean notDone = true;
        iterations = 0;
        while(notDone) {
            iterations++;
            notDone = false;
            Iterator iter = pages.iterator();
            while(iter.hasNext()) {
                Page p = (Page) iter.next();
                if(! p.calculatePR())
                    notDone = true;
            }
            if(printIterations)
                System.out.println(toString());
        }
    }
}