package com.ard.sample.component.websocket.handler;

import com.alibaba.fastjson2.JSON;
import com.ard.sample.component.websocket.model.Payload;
import com.ard.sample.component.websocket.model.WebSocketMessage;
import org.springframework.stereotype.Component;
import org.springframework.web.socket.CloseStatus;
import org.springframework.web.socket.TextMessage;
import org.springframework.web.socket.WebSocketSession;
import org.springframework.web.socket.handler.TextWebSocketHandler;

import java.io.IOException;
import java.util.*;
import java.util.concurrent.ConcurrentHashMap;

@Component
public class DockWebSocketHandler extends TextWebSocketHandler {

    // 存储用户会话：userId -> WebSocketSession
    private final Map<String, WebSocketSession> userSessions = new ConcurrentHashMap<>();

    // 订阅关系：key=订阅标识(sn+type)，value=订阅用户ID集合
    private final Map<String, Set<String>> subscriptions = new ConcurrentHashMap<>();

    // 关键：为每个WebSocketSession分配独立的锁对象，确保写操作同步
    private final Map<WebSocketSession, Object> sessionLocks = new ConcurrentHashMap<>();

    /**
     * 连接建立后回调
     */
    @Override
    public void afterConnectionEstablished(WebSocketSession session) throws Exception {
        // 从会话属性中获取认证后的用户ID
        String userId = (String) session.getAttributes().get("userId");
        if (userId == null) {
            session.close(CloseStatus.POLICY_VIOLATION.withReason("未认证"));
            return;
        }

        userSessions.put(userId, session);
        // 为新会话初始化锁对象
        sessionLocks.put(session, new Object());
        System.out.println("用户[" + userId + "]已连接，当前在线人数：" + userSessions.size());
    }

    /**
     * 处理客户端发送的消息
     */
    @Override
    protected void handleTextMessage(WebSocketSession session, TextMessage message) throws Exception {
        String userId = (String) session.getAttributes().get("userId");
        String jsonMessage = message.getPayload();

        try {
            // 解析客户端消息
            WebSocketMessage webSocketMessage = JSON.parseObject(jsonMessage, WebSocketMessage.class);
            String type = webSocketMessage.getType();
            Payload payload = webSocketMessage.getPayload();

            // 验证消息类型是否合法
            if (!Arrays.asList("status", "control", "progress", "state").contains(type)) {
                session.sendMessage(new TextMessage("不支持的消息类型：" + type));
                return;
            }

            // 处理订阅/取消订阅
            handleSubscription(userId, type, payload);

        } catch (Exception e) {
            System.err.println("消息处理错误：" + e.getMessage());
            session.sendMessage(new TextMessage("消息格式错误"));
        }
    }

    /**
     * 处理订阅/取消订阅逻辑
     */
    private void handleSubscription(String userId, String type, Payload payload) {
        String sn = payload.getSn();
        boolean subscribe = payload.isSubscribe();
        String subscriptionKey = getSubscriptionKey(sn, type); // 生成唯一订阅标识

        if (subscribe) {
            // 订阅操作
            subscriptions.computeIfAbsent(subscriptionKey, k -> ConcurrentHashMap.newKeySet()).add(userId);
            System.out.println("用户[" + userId + "]订阅了 设备[" + sn + "]的[" + type + "]类型消息");
        } else {
            // 取消订阅操作
            if (subscriptions.containsKey(subscriptionKey)) {
                subscriptions.get(subscriptionKey).remove(userId);
                if (subscriptions.get(subscriptionKey).isEmpty()) {
                    subscriptions.remove(subscriptionKey);
                }
                System.out.println("用户[" + userId + "]取消订阅了 设备[" + sn + "]的[" + type + "]类型消息");
            }
        }
    }

    /**
     * 连接关闭后回调
     */
    @Override
    public void afterConnectionClosed(WebSocketSession session, CloseStatus status) throws Exception {
        String userId = (String) session.getAttributes().get("userId");
        if (userId != null) {
            userSessions.remove(userId);
            sessionLocks.remove(session); // 移除会话锁
            // 清除该用户的所有订阅
            removeUserAllSubscriptions(userId);
            System.out.println("用户[" + userId + "]已断开连接，当前在线人数：" + userSessions.size());
        }
    }

    /**
     * 清除用户的所有订阅
     */
    private void removeUserAllSubscriptions(String userId) {
        for (Map.Entry<String, Set<String>> entry : subscriptions.entrySet()) {
            entry.getValue().remove(userId);
            if (entry.getValue().isEmpty()) {
                subscriptions.remove(entry.getKey());
            }
        }
    }

    /**
     * 向订阅了特定设备特定类型的用户发送消息
     */
    public void sendMessageToSubscribers(String sn, String type, String content) {
        String subscriptionKey = getSubscriptionKey(sn, type);
        Set<String> subscriberIds = subscriptions.getOrDefault(subscriptionKey, new HashSet<>());

        if (subscriberIds.isEmpty()) {
            //System.out.println("没有用户订阅 设备[" + sn + "]的[" + type + "]类型消息");
            return;
        }

        try {
            // 构建发送的消息
//            WebSocketMessage message = new WebSocketMessage();
//            message.setType(type);
//
//            Payload payload = new Payload();
//            payload.setSn(sn);
//            payload.setSubscribe(true); // 仅作为标识，无实际意义
//            message.setPayload(payload);
//
//            String jsonMessage = JSON.toJSONString(message);

            // 向所有订阅者发送消息
            for (String userId : subscriberIds) {
                WebSocketSession session = userSessions.get(userId);
                // 1. 检查会话是否有效
                if (session == null || !session.isOpen()) {
                    // 移除无效会话
                    userSessions.remove(userId);
                    sessionLocks.remove(session);
                    continue;
                }

                // 2. 获取当前会话的锁对象，确保同步写操作
                Object lock = sessionLocks.get(session);
                if (lock == null) {
                    continue; // 理论上不会出现，防止NPE
                }

                // 3. 同步发送消息，避免并发冲突
                synchronized (lock) {
                    session.sendMessage(new TextMessage(content));
                    System.out.println("向用户[" + userId + "]发送 设备[" + sn + "]的[" + type + "]类型消息:" + content);
                }
//                if (session != null && session.isOpen()) {
//                    session.sendMessage(new TextMessage(content));
//                    System.out.println("向用户[" + userId + "]发送 设备[" + sn + "]的[" + type + "]类型消息");
//                    System.out.println(content);
//                }
            }
        } catch (IOException e) {
            System.err.println("发送消息错误：" + e.getMessage());
        }
    }

    /**
     * 生成订阅标识（sn+type的组合）
     */
    private String getSubscriptionKey(String sn, String type) {
        return sn + ":" + type;
    }
}