import cs1705.*;

// -------------------------------------------------------------------------
/**
 *  This robot adds extra behaviors to a VPIRobot that give it powerful
 *  navigation abilities.
 * 
 *  @author  Stephen Edwards
 *  @version 2003.09.21
 */
public class NavigatorBot
    extends VPIRobot
{
    //~ Constructors ..........................................................

    // ----------------------------------------------------------
    /**
     * Construct a navigator robot by specifying its starting state.
     * The parameters are just passed to the corresponding VPIRobot
     * constructor.
     */
    public NavigatorBot( int       street,
                         int       avenue,
                         Direction facing,
                         int       numBeepers )
    {
        super( street, avenue, facing, numBeepers );
    }


    //~ Methods ...............................................................

    // ----------------------------------------------------------
    /**
     * Make a 270-degree turn left.
     */
    public void turnRight()
    {
        turnLeft();
        turnLeft();
        turnLeft();
    }


    // ----------------------------------------------------------
    /**
     * Turn until the robot is facing north.
     */
    public void faceNorth()
    {
        while ( !facingNorth() )
        {
            turnLeft();
        }
    }


    // ----------------------------------------------------------
    /**
     * Turn until the robot is facing south.
     */
    public void faceSouth()
    {
        while ( !facingSouth() )
        {
            turnLeft();
        }
    }


    // ----------------------------------------------------------
    /**
     * Turn until the robot is facing east.
     */
    public void faceEast()
    {
        while ( !facingEast() )
        {
            turnLeft();
        }
    }
    
    
    // ----------------------------------------------------------
    /**
     * Turn until the robot is facing west.
     */
    public void faceWest()
    {
        while ( !facingWest() )
        {
            turnLeft();
        }
    }
    
    
    // ----------------------------------------------------------
    /**
     * Move the specified number of steps forward.
     * 
     * @param distance the number of steps to take
     */
    public void move( int distance )
    {
        int count = 0;
        while ( count < distance )
        {
            move();
            count++;
        }
    }
    
    
    // ----------------------------------------------------------
    /**
     * Move to the specified intersection.
     * 
     * @param street the street number of the destination
     * @param avenue the avenue number of the destination
     */
    public void moveTo( int street, int avenue )
    {
        moveToStreet( street );
        moveToAvenue( avenue );
    }
    
    
    // ----------------------------------------------------------
    /**
     * Move to the specified street.
     * 
     * @param desiredStreet the street number of the destination
     */
    public void moveToStreet( int desiredStreet )
    {
        if ( desiredStreet < street() )
        {
            faceSouth();
            move( street() - desiredStreet );
        }
        else
        {
            faceNorth();
            move( desiredStreet - street() );
        }
    }
    
    
    // ----------------------------------------------------------
    /**
     * Move to the specified avenue.
     * 
     * @param desiredAvenue the avenue number of the destination
     */
    public void moveToAvenue( int desiredAvenue )
    {
        if ( desiredAvenue < avenue() )
        {
            faceWest();
            move( avenue() - desiredAvenue );
        }
        else
        {
            faceEast();
            move( desiredAvenue - avenue() );
        }
    }
}