package election;

import java.util.StringTokenizer;

/* A voter's ranked list of candidates.  This is simply a queue of
 * strings, with the top-ranked candidate at the front.  The ballot
 * also has a weight (how many votes does it count for?).  We provide
 * a nice constructor that obtains a ballot from a string.
 */

public class Ballot extends sequence.ArrayQueue {

  protected float weight = 1;

  /** Constructs a Ballot holding the names in this string.
   * The names are assumed to be comma-separated.
   * For example, "Eckert, Mauchly, von Neumann" would return
   * a ballot with 3 names, with Eckert on top.
   */
  public Ballot(String s) {
    super(ballotLength(s));   // make queue just long enough for this ballot
    StringTokenizer st = tokenizer(s);
    while (st.hasMoreTokens()) 
      enqueue(st.nextToken().trim());
  }

  /** Returns the top name on this ballot. */
  public String topName() {
    return (String) front();
  }

  /** Returns the current weight of this ballot. */
  public float weight() {
    return weight;
  }

  /** Multiplies the weight of this ballot by f. 
   * Use this method to reduce the value of a ballot that has been partly used up. 
   */
  public void multWeight(float f) {
    this.weight *= f;
  }

  // ------- PROTECTED CONVENIENCE METHODS -------

  protected static StringTokenizer tokenizer(String s) {
    return new StringTokenizer(s, ",");
  }
  
  protected static int ballotLength(String s) {
    StringTokenizer st = tokenizer(s);
    int i;
    for (i=0; st.hasMoreTokens(); i++) 
      st.nextToken();
    return i;
  }
}