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