package com.moon.server.service.all;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;

import javax.annotation.PostConstruct;
import javax.websocket.*;
import javax.websocket.server.ServerEndpoint;
import java.io.IOException;
import java.util.concurrent.CopyOnWriteArraySet;
import java.util.concurrent.atomic.AtomicInteger;

/**
 * WebSocket服务类
 * @author WWW
 */
@ServerEndpoint(value = "/ws/select")
@Component
public class WebSocketService {
    @PostConstruct
    public void init() {
        System.out.println("websocket 加载");
    }

    private final static Logger log = LoggerFactory.getLogger(WebSocketService.class);

    private static final AtomicInteger ONLINE_COUNT = new AtomicInteger(0);

    /**
     * 用来存放每个客户端对应的Session对象（线程安全Set）
     */
    private final static CopyOnWriteArraySet<Session> SESSION_SET = new CopyOnWriteArraySet<Session>();

    /**
     * 连接建立成功调用的方法
     */
    @OnOpen
    public void onOpen(Session session) {
        SESSION_SET.add(session);

        int cnt = ONLINE_COUNT.incrementAndGet();
        log.info("有连接加入，当前连接数为：{}", cnt);
        sendMessage(session, "连接成功");
    }

    /**
     * 连接关闭调用的方法
     */
    @OnClose
    public void onClose(Session session) {
        SESSION_SET.remove(session);

        int cnt = ONLINE_COUNT.decrementAndGet();
        log.info("有连接关闭，当前连接数为：{}", cnt);
    }

    /**
     * 收到客户端消息后调用的方法
     *
     * @param message 客户端发送过来的消息
     */
    @OnMessage
    public void onMessage(String message, Session session) {
        log.info("来自客户端的消息：{}", message);
        sendMessage(session, "收到消息，消息内容：" + message);
    }

    /**
     * 出现错误
     */
    @OnError
    public void onError(Session session, Throwable error) {
        log.error("发生错误：{}，Session ID： {}", error.getMessage(), session.getId());
    }

    /**
     * 发送消息，实践表明，每次浏览器刷新，session会发生变化。
     */
    public static void sendMessage(Session session, String message) {
        try {
            // session.getAsyncRemote().sendText(message)
            synchronized (session){
                session.getBasicRemote().sendText(message);
            }
        } catch (Exception ex) {
            log.error("发送消息出错：{}", ex.getMessage());
        }
    }

    /**
     * 群发消息
     */
    public static void broadCastInfo(String message) throws IOException {
        for (Session session : SESSION_SET) {
            if (session.isOpen()) {
                sendMessage(session, message);
            }
        }
    }

    /**
     * 指定Session发送消息
     */
    public static void sendMessage(String message, String sessionId) throws IOException {
        Session session = null;
        for (Session s : SESSION_SET) {
            if (s.getId().equals(sessionId)) {
                session = s;
                break;
            }
        }

        if (session != null) {
            sendMessage(session, message);
        } else {
            log.info("没有找到你指定ID的会话：{}", sessionId);
        }
    }
}