import java.awt.*;public class Enemy {	// Constants to represent the direction of the Enemy	private final int LEFT =  0;	private final int RIGHT = 1;	private final int UP =    2;	private final int DOWN =  3;	// The size of the Enemy.	private final int SIZE = 8;	private boolean isVillain;	//The colour of the enemy;	private final int GREEN = 1;	private final int RED =   2;	private int color;	private int xPos, yPos;	private int direction;	private int destX, destY; // The random destination position	private int goldX, goldY;	//The speed of the Enemy	private final int SPEED = 5;	public Enemy(){		xPos = 20;		yPos = 20;		isVillain = false;		setDestinationPosition();	}	public Enemy (int x, int y, boolean isRedVillain) {		xPos = x;		yPos = y;		direction = UP;		isVillain = isRedVillain;		setDestinationPosition();		if(isVillain){			color = RED;		}else{			color = GREEN;		}	}	private void setDestinationPosition(){		if(isVillain){			destX = goldX;			destY = goldY;		}else{			destX = (int)(Math.random() * 440 + 10);			destY = (int)(Math.random() * 440 + 10);		}	}	public void setGoldPosition(int x, int y){		goldX = x;		goldY = y;	}	private void setDirection(){		if(isVillain){			if(goldX < xPos - SIZE){				direction = LEFT;			}else if(goldX > xPos + SIZE){				direction = RIGHT;			}else{				if(goldY < yPos - SIZE){					direction = UP;				}else if(goldY > yPos + SIZE){					direction = DOWN;				}else{					setDestinationPosition();					return;				}			}		}else{			if(destX < xPos - SIZE){				direction = LEFT;			}else if(destX > xPos + SIZE){				direction = RIGHT;			}else{				if(destY < yPos - SIZE){					direction = UP;				}else if(destY > yPos + SIZE){					direction = DOWN;				}else{					setDestinationPosition();					return;				}			}		}	}	//Pass the position of the enemy.	public int getX(){		return xPos - SIZE;	}	public int getY(){		return yPos - SIZE;	}	public int getSize(){		return SIZE;	}	private boolean isGotDestinationPoint(){		if(isVillain){			Point destinationPoint;			Rectangle villainBox;			destinationPoint = new Point(goldX,goldY);			villainBox = new Rectangle(xPos - SIZE, yPos - SIZE, SIZE * 2, SIZE * 2);			return villainBox.contains(destinationPoint);		}		if(isVillain == false){			Point destinationPoint;			Rectangle enemyBox;			destinationPoint = new Point(destX, destY);			enemyBox = new Rectangle(xPos - SIZE, yPos - SIZE, SIZE * 2, SIZE * 2);			return enemyBox.contains(destinationPoint);		}		return false;	}	//To change the facing direction of the Enemy.	//To move the Enemy	public void move(Rectangle boundary){		setDirection();		if(isGotDestinationPoint()){			setDestinationPosition();			setDirection();		}		if(direction == UP && yPos - SIZE > boundary.y){			yPos -= SPEED;		}else if(direction == DOWN && yPos + SIZE < boundary.y + boundary.height){			yPos += SPEED;		}else if(direction == LEFT && xPos - SIZE > boundary.x){			xPos -= SPEED;		}else if(direction == RIGHT && xPos + SIZE < boundary.x + boundary.width){			xPos += SPEED;		}	}	// Display the Enemy.  The direction the Enemy is facing	// is indicated by a narrow rectangle.	public void draw(Graphics g) {		// Draw the main body of the Enemy		if(color == GREEN){			g.setColor(Color.GREEN);		}else if(color == RED){			g.setColor(Color.RED);		}		g.fillRect(xPos-SIZE, yPos-SIZE, 2*SIZE, 2*SIZE);		g.setColor(Color.black);		g.drawRect(xPos-SIZE, yPos-SIZE, 2*SIZE, 2*SIZE);		// Calculate the position of the direction indicator		Rectangle directionIndicator;		if (direction == UP) {			directionIndicator = new Rectangle(xPos-SIZE+2, yPos-SIZE+2, 2*SIZE-4, 3);		} else if (direction == DOWN) {			directionIndicator = new Rectangle(xPos-SIZE+2, yPos+SIZE-5, 2*SIZE-4, 3);		} else if (direction == LEFT) {			directionIndicator = new Rectangle(xPos-SIZE+2, yPos-SIZE+2, 3, 2*SIZE-4);		} else {			directionIndicator = new Rectangle(xPos+SIZE-5, yPos-SIZE+2, 3, 2*SIZE-4);		}		// Draw the direction indicator		g.setColor(Color.white);		g.fillRect(directionIndicator.x, directionIndicator.y, directionIndicator.width, directionIndicator.height);		g.setColor(Color.black);		g.drawRect(directionIndicator.x, directionIndicator.y, directionIndicator.width, directionIndicator.height);	}}