import java.util.Random;

public class Randomizer{

	public static Random theInstance = null;
	
	public Randomizer(){
		
	}
	
	public static Random getInstance(){
		if(theInstance == null){
			theInstance = new Random();
		}
		return theInstance;
	}
	
	/**
	 * Return a random boolean value.
	 * @return True or false value simulating a coin flip.
	 */
	public static boolean nextBoolean(){
		return Randomizer.getInstance().nextBoolean();
	}

	/**
	 * This method simulates a weighted coin flip which will return
	 * true with the probability passed as a parameter.
	 * 
	 * @param	probability	The probability that the method returns true, a value between 0 to 1 inclusive. 
	 * @return True or false value simulating a weighted coin flip.
	 */
	public static boolean nextBoolean(double probability){
		return Randomizer.nextDouble() < probability;
	}
	
	/**
	 * This method returns a random integer.
	 * @return A random integer.
	 */
	public static int nextInt(){
		return Randomizer.getInstance().nextInt();
	}

	/**
	 * This method returns a random integer between 0 and n, exclusive.
	 * @param n	The maximum value for the range.
	 * @return A random integer between 0 and n, exclusive.
	 */
	public static int nextInt(int n){
		return Randomizer.getInstance().nextInt(n);
	}

	/**
	 * Return a number between min and max, inclusive.
	 * @param min	The minimum integer value of the range, inclusive.
	 * @param max	The maximum integer value in the range, inclusive.
	 * @return A random integer between min and max.
	 */
	public static int nextInt(int min, int max){
		return min + Randomizer.nextInt(max - min + 1);
	}

	/**
	 * Return a random double between 0 and 1.
	 * @return A random double between 0 and 1.
	 */
	public static double nextDouble(){
		return Randomizer.getInstance().nextDouble();
	}

	/**
	 * Return a random double between min and max.
	 * @param min The minimum double value in the range.
	 * @param max The maximum double value in the rang.
	 * @return A random double between min and max.
	 */
	public static double nextDouble(double min, double max){
		return min + (max - min) * Randomizer.nextDouble();
	}

	
}