// Chapter 4, Exercise Set 1, Question 7 TurningDarter Class
// The turningDarter has all the characteristics of a darter fish
// except that it has a 0.1 chance of turning right or left before it
// tries to move forward.

import java.awt.Color;
import java.util.Random;

public class TurningDarter extends DarterFish
{
  // Instance Variables: Encapsulated data for EACH TurningDarter fish
  private double probOfTurning;
                 // defines likelihood of turning in each timestep
  private double probOfRight;
                 //defines likelihood of turning right

  // constructors

  /** Constructs a turning darter fish at the specified location in a
   *  given environment. This turning darter is colored magenta.
   *  (Precondition: parameters are non-null)
   *  @param env	environment in which fish will live
   *  @param loc	location of the new fish in <code>env</code>
   **/
  public TurningDarter(Environment env, Location loc)
  {
    // Construct and initialize the attributes inherited from Fish.
    super(env, loc, env.randomDirection(), Color.magenta);
    probOfTurning = 0.1;
    probOfRight = 0.5;
  }

  /** Constructs a turning darter fish at the specified location with
   *  the direction in a given environment.
   *  This turning darter is colored magenta.
   *  (Precondition: parameters are non-null)
   *  @param env	environment in which fish will live
   *  @param loc	location of the new fish in <code>env</code>
   *  @param dir	direction the new fish is facing
   **/
  public TurningDarter(Environment env, Location loc, Direction dir)
  {
    // Construct and initialize the attributes inherited from Fish.
    super(env, loc, dir, Color.magenta);
    probOfTurning = 0.1;
    probOfRight = 0.5;
  }

  /** Constructs a turning darter fish of the specified color at the
   *  specified location and direction.
   *  (Precondition: parameters are non-null)
   *  @param env	environment in which fish will live
   *  @param loc	location of the new fish in <code>env</code>
   *  @param dir	direction the new fish is facing
   *  @param col	color of the new fish
   **/
  public TurningDarter(Environment env, Location loc, Direction dir,
                       Color col)
  {
    // Construct and initialize the attributes inherited from Fish.
    super(env, loc, dir, col);
    probOfTurning = 0.1;
    probOfRight = 0.5;
  }

  /** Returns a string representing key information about this fish.
   *  @return	a string indicating the fish's ID and location
   **/
  public String toString()
  {
    return "TurningDarter " + super.toString();
  }

  /** Moves this fish in its environment.
   *  A turning darter fish first sees if it should turn left or right
   *  and then darts forward (as specified in nextLocation) if possible,
   *  or reverses direction (without moving) if it cannot move forward.
   **/
  protected void move()
  {
    // If this is the 0.1 chance of turning, turn left or right
    Random randNumGen = RandNumGenerator.getInstance();
    if ( randNumGen.nextDouble() < probOfTurning )
    {
      turnRightOrLeft(direction());
      Debug.println(toString() + " Turned and now facing " +
                    direction());
    }
    super.move();
  }

  /** Turns this fish right or left
   **/
  protected void turnRightOrLeft(Direction dir)
  {
    Random randNumGen = RandNumGenerator.getInstance();
    if (randNumGen.nextDouble() < probOfRight)
    {
      changeDirection(dir.toRight());
    }
    else
    {
      changeDirection(dir.toLeft());
    }
  }
}