/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package websocket.snake;
import java.io.IOException;
import java.util.ArrayDeque;
import java.util.Collection;
import java.util.Deque;
import jakarta.websocket.CloseReason;
import jakarta.websocket.CloseReason.CloseCodes;
import jakarta.websocket.Session;
public class Snake {
private static final int DEFAULT_LENGTH = 5;
private final int id;
private final Session session;
private Direction direction;
private int length = DEFAULT_LENGTH;
private Location head;
private final Deque<Location> tail = new ArrayDeque<>();
private final String hexColor;
public Snake(int id, Session session) {
this.id = id;
this.session = session;
this.hexColor = SnakeAnnotation.getRandomHexColor();
resetState();
}
private void resetState() {
this.direction = Direction.NONE;
this.head = SnakeAnnotation.getRandomLocation();
this.tail.clear();
this.length = DEFAULT_LENGTH;
}
private synchronized void kill() {
resetState();
sendMessage("{\"type\": \"dead\"}");
}
private synchronized void reward() {
length++;
sendMessage("{\"type\": \"kill\"}");
}
protected void sendMessage(String msg) {
try {
session.getBasicRemote().sendText(msg);
} catch (IOException ioe) {
CloseReason cr = new CloseReason(CloseCodes.CLOSED_ABNORMALLY, ioe.getMessage());
try {
session.close(cr);
} catch (IOException ioe2) {
// Ignore
}
}
}
public synchronized void update(Collection<Snake> snakes) {
Location nextLocation = head.getAdjacentLocation(direction);
if (nextLocation.x >= SnakeAnnotation.PLAYFIELD_WIDTH) {
nextLocation.x = 0;
}
if (nextLocation.y >= SnakeAnnotation.PLAYFIELD_HEIGHT) {
nextLocation.y = 0;
}
if (nextLocation.x < 0) {
nextLocation.x = SnakeAnnotation.PLAYFIELD_WIDTH;
}
if (nextLocation.y < 0) {
nextLocation.y = SnakeAnnotation.PLAYFIELD_HEIGHT;
}
if (direction != Direction.NONE) {
tail.addFirst(head);
if (tail.size() > length) {
tail.removeLast();
}
head = nextLocation;
}
handleCollisions(snakes);
}
private void handleCollisions(Collection<Snake> snakes) {
for (Snake snake : snakes) {
boolean headCollision = id != snake.id && snake.getHead().equals(head);
boolean tailCollision = snake.getTail().contains(head);
if (headCollision || tailCollision) {
kill();
if (id != snake.id) {
snake.reward();
}
}
}
}
public synchronized Location getHead() {
return head;
}
public synchronized Collection<Location> getTail() {
return tail;
}
public synchronized void setDirection(Direction direction) {
this.direction = direction;
}
public synchronized String getLocationsJson() {
StringBuilder sb = new StringBuilder();
sb.append(String.format("{\"x\": %d, \"y\": %d}",
Integer.valueOf(head.x), Integer.valueOf(head.y)));
for (Location location : tail) {
sb.append(',');
sb.append(String.format("{\"x\": %d, \"y\": %d}",
Integer.valueOf(location.x), Integer.valueOf(location.y)));
}
return String.format("{\"id\":%d,\"body\":[%s]}",
Integer.valueOf(id), sb.toString());
}
public int getId() {
return id;
}
public String getHexColor() {
return hexColor;
}
}