/*
 * Copyright © 2026 Qiantong Technology Co., Ltd.
 * qModel Model Platform(Open Source Edition)
 *  *
 * License:
 * Released under the Apache License, Version 2.0.
 * You may use, modify, and distribute this software for commercial purposes
 * under the terms of the License.
 *  *
 * Special Notice:
 * All derivative versions are strictly prohibited from modifying or removing
 * the default system logo and copyright information.
 * For brand customization, please apply for brand customization authorization via official channels.
 *  *
 * More information: https://qmodel.qiantong.tech/business.html
 *  *
 * ============================================================================
 *  *
 * 版权所有 © 2026 江苏千桐科技有限公司
 * qModel 模型平台（开源版）
 *  *
 * 许可协议：
 * 本项目基于 Apache License 2.0 开源协议发布，
 * 允许在遵守协议的前提下进行商用、修改和分发。
 *  *
 * 特别说明：
 * 所有衍生版本不得修改或移除系统默认的 LOGO 和版权信息；
 * 如需定制品牌，请通过官方渠道申请品牌定制授权。
 *  *
 * 更多信息请访问：https://qmodel.qiantong.tech/business.html
 */

package tech.qiantong.qmodel.module.system.controller.admin.example.websocket;

import java.util.concurrent.Semaphore;
import javax.websocket.OnClose;
import javax.websocket.OnError;
import javax.websocket.OnMessage;
import javax.websocket.OnOpen;
import javax.websocket.Session;
import javax.websocket.server.ServerEndpoint;

import tech.qiantong.qmodel.websocket.SemaphoreUtils;
import tech.qiantong.qmodel.websocket.WebSocketUsers;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;

/**
 * websocket 消息处理
 *
 * @author anivia
 */
@Component
@ServerEndpoint("/websocket/message")
public class WebSocketServer
{
    /**
     * WebSocketServer 日志控制器
     */
    private static final Logger LOGGER = LoggerFactory.getLogger(WebSocketServer.class);

    /**
     * 默认最多允许同时在线人数100
     */
    public static int socketMaxOnlineCount = 100;

    private static Semaphore socketSemaphore = new Semaphore(socketMaxOnlineCount);

    /**
     * 连接建立成功调用的方法
     */
    @OnOpen
    public void onOpen(Session session) throws Exception
    {
        boolean semaphoreFlag = false;
        // 尝试获取信号量
        semaphoreFlag = SemaphoreUtils.tryAcquire(socketSemaphore);
        if (!semaphoreFlag)
        {
            // 未获取到信号量
            LOGGER.error("\n 当前在线人数超过限制数- {}", socketMaxOnlineCount);
            WebSocketUsers.sendMessageToUserByText(session, "当前在线人数超过限制数：" + socketMaxOnlineCount);
            session.close();
        }
        else
        {
            // 添加用户
            WebSocketUsers.put(session.getId(), session);
            LOGGER.info("\n 建立连接 - {}", session);
            LOGGER.info("\n 当前人数 - {}", WebSocketUsers.getUsers().size());
            WebSocketUsers.sendMessageToUserByText(session, "连接成功");
        }
    }

    /**
     * 连接关闭时处理
     */
    @OnClose
    public void onClose(Session session)
    {
        LOGGER.info("\n 关闭连接 - {}", session);
        // 移除用户
        boolean removeFlag = WebSocketUsers.remove(session.getId());
        if (!removeFlag)
        {
            // 获取到信号量则需释放
            SemaphoreUtils.release(socketSemaphore);
        }
    }

    /**
     * 抛出异常时处理
     */
    @OnError
    public void onError(Session session, Throwable exception) throws Exception
    {
        if (session.isOpen())
        {
            // 关闭连接
            session.close();
        }
        String sessionId = session.getId();
        LOGGER.info("\n 连接异常 - {}", sessionId);
        LOGGER.info("\n 异常信息 - {}", exception);
        // 移出用户
        WebSocketUsers.remove(sessionId);
        // 获取到信号量则需释放
        SemaphoreUtils.release(socketSemaphore);
    }

    /**
     * 服务器接收到客户端消息时调用的方法
     */
    @OnMessage
    public void onMessage(String message, Session session)
    {
        String msg = message.replace("你", "我").replace("吗", "");
        WebSocketUsers.sendMessageToUserByText(session, msg);
    }
}
