package edu.marlboro.cs.prisoner;
/**
 * <p> A prisoner's dilemma player that chooses randomly 
 *     betweeen COOPERATE and DEFECT strategies based on
 *     its internal cooperateProbablity.
 * </p>
 * <p> The default probability of cooperation is 0.5.
 * </p>
 *
 * @author Jim Mahoney
 * @version $Id: RandomPlayer.java 12423 2007-04-05 06:04:42Z mahoney $
 */
public class RandomPlayer extends Player {
    private static final double DEFAULT_COOPERATE_PROBABILITY = 0.5;
    private double cooperateProbability;
    public RandomPlayer(){
	init();
	setCooperateProbability(DEFAULT_COOPERATE_PROBABILITY);
    }
    public RandomPlayer(String inputName){
	init(inputName);
	setCooperateProbability(DEFAULT_COOPERATE_PROBABILITY);
    }
    /**
     * 0 <= inputCooperateProbability <= 1
     */
    public RandomPlayer(String inputName, double inputCooperateProbability){
	init(inputName);
	if (inputCooperateProbability < 0.0 || 
	    inputCooperateProbability > 1.0){
	    inputCooperateProbability = 0.5;
	}
	setCooperateProbability(inputCooperateProbability);
    }
    public void setCooperateProbability(double probability){
	cooperateProbability = probability;
    }
    public double getCooperateProbability(){
	return cooperateProbability;
    }
    public int getNextMove(int opponentId){
	// 0 <= cooperateProbability <= 1
	// 0 <= Math.random() < 1
	if (Math.random() < cooperateProbability){
	    return Game.COOPERATE;
	}
	else {
	    return Game.DEFECT;
	}
	// // If the fact that COOPERATE=0 and DEFECT=1 is used,
	// // this calculation can be done with just
	// return (int)(Math.random()/cooperateProbability);
	// // which is probably faster but less general.
    }
    public String getInternalState(){
	return toString() + " : state=(p=" + cooperateProbability +
	    "); score=" + getScore();
    }
}