Class Robot

/**
 *  Title:  class Robot
 *  Description: Simple representation of a robot.
 *  Copyright (c) 2004
 *  Organisation: UCL
 *  @author Graham Roberts 
 *  @version 1.2 10/04
 */

import java.awt.*;

class Robot
{
  private int xpos;
  private int ypos;
  private int direction;
  private Room room;
  private int speed;
  private boolean hasWidget;

  public Robot(int x, int y, int d, Room r)
  {
    xpos = x;
    ypos = y;
    direction = d;
    hasWidget = false;
    room = r;
    room.setRobotPosition(xpos, ypos, direction);
    speed = 1000;
  }

  public void forward()
  {
    pause();
    if (!canMoveForward())
    {
      room.beep();
      return;
    }
    switch (direction)
    {
      case Room.NORTH:
        ypos--;
        break;
      case Room.EAST:
        xpos++;
        break;
      case Room.SOUTH:
        ypos++;
        break;
      case Room.WEST:
        xpos--;
        break;
    }
    room.setRobotPosition(xpos, ypos, direction);
  }

  public void left()
  {
    pause();
    switch (direction)
    {
      case Room.NORTH:
        direction = Room.WEST;
        break;
      case Room.EAST:
        direction = Room.NORTH;
        break;
      case Room.SOUTH:
        direction = Room.EAST;
        break;
      case Room.WEST:
        direction = Room.SOUTH;
        break;
    }
    room.setRobotPosition(xpos, ypos, direction);
  }

  public void right()
  {
    pause();
    switch (direction)
    {
      case Room.NORTH:
        direction = Room.EAST;
        break;
      case Room.EAST:
        direction = Room.SOUTH;
        break;
      case Room.SOUTH:
        direction = Room.WEST;
        break;
      case Room.WEST:
        direction = Room.NORTH;
        break;
    }
    room.setRobotPosition(xpos, ypos, direction);
  }

  public boolean canMoveForward()
  {
    switch (direction)
    {
      case Room.NORTH:
        if ((ypos > 0) && !room.isObstacleAt(xpos, ypos - 1))
        {
          return true;
        }
        break;
      case Room.EAST:
        if ((xpos < room.getRoomSizeX() - 1) && !room.isObstacleAt(xpos + 1, ypos))
        {
          return true;
        }
        break;
      case Room.SOUTH:
        if ((ypos < room.getRoomSizeY() - 1) && !room.isObstacleAt(xpos, ypos + 1))
        {
          return true;
        }
        break;
      case Room.WEST:
        if ((xpos > 0) && !room.isObstacleAt(xpos - 1, ypos))
        {
          return true;
        }
        break;
    }
    return false;
  }

  public boolean atDoor()
  {
    int wall = room.getDoorWall();
    int position = room.getDoorPosition();
    int x = 0;
    int y = 0;

    switch (wall)
    {
      case Room.NORTH:
        x = position;
        y = 0;
        break;
      case Room.EAST:
        x = room.getRoomSizeX() - 1;
        y = position;
        break;
      case Room.SOUTH:
        x = position;
        y = room.getRoomSizeY() - 1;
        break;
      case Room.WEST:
        x = 0;
        y = position;
        break;
    }

    if ((xpos == x) && (ypos == y))
    {
      return true;
    }
    else
    {
      return false;
    }
  }

  public void done()
  {
    room.setRobotColour(Color.green);
  }

  public void setSpeed(double seconds)
  {
    speed = (int) (seconds * 1000);
  }

  public boolean atWidget()
  {
    return room.isWidgetAt(xpos, ypos);
  }

  public void pickUpWidget()
  {
    if (atWidget() && !hasWidget)
    {
      hasWidget = true;
      room.getWidget(xpos, ypos);
    }
    else
    {
      room.beep();
    }
  }

  public void dropWidget()
  {
    if (hasWidget)
    {
      room.setWidget(xpos, ypos);
      hasWidget = false;
    }
    else
    {
      room.beep();
    }
  }

  private void pause()
  {
    try
    {
      Thread.sleep(speed);
    }
    catch (InterruptedException e)
    {
    }
  }
}