/**
 * 
 */
package de.fhswf.in.inf.java1.aufgabe7;

import java.util.Random;

/**
 * Simulates a shell game.
 *
 * @author $Author: $
 * @version $Revision: $, $Date: $ UTC
 */
public class Spiel
{
   private int nussPlatz = -1;

   public static final int MAXHUET = 3;

   private Random rnd = new Random();

   /**
    * Places the pea under a shell.
    *
    */
   private void nussVerstecken()
   {
      nussPlatz = rnd.nextInt(MAXHUET);
   }

   /**
    * Returns an empty shell, which the user didn't choose.
    *
    * @param ersterTipp
    *           The first choice of the player.
    * @return An empty shell number of the remaining shells
    */
   private int zeigeHuetchen(int ersterTipp)
   {
      int erg = -1;
      if (ersterTipp != nussPlatz)
      {
         erg = MAXHUET - nussPlatz - ersterTipp;
      }
      else
      {
         erg = (ersterTipp + rnd.nextInt(MAXHUET - 1)) % MAXHUET;
      }
      return erg;
   }

   /**
    * Returns the shell number with the pea.
    *
    * @return The shell number
    */
   private int aufloesung()
   {
      return nussPlatz;
   }

   /**
    * Simulates a complete game.
    *
    * @param spieler
    *           The player who plays.
    * @return Boolean, if the player choose correct.
    */
   public boolean spielDurchlauf(Spieler spieler)
   {
      if (spieler == null)
      {
         throw new IllegalArgumentException("A player hast to play.");
      }
      int tipp = -1;
      nussVerstecken();
      tipp = spieler.ersterTipp();
      assert tipp >= 0 && tipp <= MAXHUET;
      tipp = spieler.zweiterTipp(zeigeHuetchen(tipp));
      assert tipp >= 0 && tipp <= MAXHUET;
      return tipp == aufloesung();
   }

}