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

import com.alibaba.fastjson2.JSON;

import com.ard.vtdu.domain.ArdVtdu;
import com.ard.work.component.websocket.utils.WebSocketUtil;
import com.ard.work.domain.message.BaseMessage;
import com.ard.work.domain.receiver.BoxStreamUrlReceiver;
import com.ard.work.service.ITyService;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.Objects;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;

@Service
@Slf4j
public class UavStreamManager {

    private static final String STREAM_LOG_PREFIX = "【stream】";
    private static final String STREAM_NOT_FOUND_MSG = "Box stream not found: ";
    private static final String STREAM_CLOSED_MSG = "Stream closed due to no active users: ";
    private static final String STREAM_IN_USE_MSG = "Stream is still in use, remaining users: ";

    @Resource
    private ITyService tyService;

    // 盒子拉流地址缓存 key:boxSn value: webrtcUrl
    public static final ConcurrentMap<String, String> BOX_STREAM_PULL_MAP = new ConcurrentHashMap<>();
    // 盒子拉流用户集合缓存 key:boxSn value:Set<UserId>
    public static final ConcurrentMap<String, Set<Long>> STREAM_USER_MAP = new ConcurrentHashMap<>();

    /**
     * 开始拉流
     *
     * @param boxSn  盒子序列号
     * @param userId 用户ID
     */
    public void subscribe(String boxSn, Long userId) {

        STREAM_USER_MAP.computeIfAbsent(boxSn, k -> ConcurrentHashMap.newKeySet()).add(userId);
        BoxStreamUrlReceiver streamReceiver = getWebrtcUrl(boxSn);
        String webrtcUrl = streamReceiver.getRtc();
        if (Objects.equals(webrtcUrl, "")) {
            log.warn("{}{}{}", STREAM_LOG_PREFIX, STREAM_NOT_FOUND_MSG, boxSn);
            BaseMessage<String> baseMessage = new BaseMessage<>("stream", STREAM_NOT_FOUND_MSG + boxSn);
            sendMessageToUser(userId, JSON.toJSONString(baseMessage));
        }
        BOX_STREAM_PULL_MAP.put(boxSn, webrtcUrl);
        BaseMessage<BoxStreamUrlReceiver> baseMessage = new BaseMessage<>("stream", streamReceiver);
        sendMessageToUser(userId, JSON.toJSONString(baseMessage));
    }

    /**
     * 停止拉流
     *
     * @param boxSn  盒子序列号
     * @param userId 用户ID
     */
    public void unsubscribe(String boxSn, Long userId) {
        synchronized (this) {
            Set<Long> users = STREAM_USER_MAP.get(boxSn);
            if (users == null) {
                log.warn("{}No active users for box: {}", STREAM_LOG_PREFIX, boxSn);
                BaseMessage<String> baseMessage = new BaseMessage<>("stream", "No active users for box: " + boxSn);
                sendMessageToUser(userId, JSON.toJSONString(baseMessage));
                return;
            }

            users.remove(userId);
            String message = "";
            if (users.isEmpty()) {
                BOX_STREAM_PULL_MAP.remove(boxSn);
                STREAM_USER_MAP.remove(boxSn);
                log.info("{}{}{}", STREAM_LOG_PREFIX, STREAM_CLOSED_MSG, boxSn);
                message = STREAM_CLOSED_MSG + boxSn;
            } else {
                log.info("{}{}{}", STREAM_LOG_PREFIX, STREAM_IN_USE_MSG, users);
                message = STREAM_IN_USE_MSG + boxSn;
            }
            BaseMessage<String> baseMessage = new BaseMessage<>("stream", message);
            sendMessageToUser(userId, JSON.toJSONString(baseMessage));
        }
    }

    /**
     * 停止拉流
     *
     * @param userId 用户ID
     */
    public void stopAllPullStreamByUser(Long userId) {
        synchronized (this) {
            STREAM_USER_MAP.forEach((boxSn, users) -> unsubscribe(boxSn, userId));
        }
    }

    /**
     * 发送消息给指定用户
     *
     * @param userId  用户ID
     * @param message 消息内容
     */
    private void sendMessageToUser(Long userId, String message) {
        try {
            WebSocketUtil.sendMessage(userId, message);
        } catch (Exception e) {
            log.error("{}Failed to send message to user: {}", STREAM_LOG_PREFIX, userId, e);
        }
    }


    /**
     * 通过盒子编号获取webrtc地址
     *
     * @param boxSn 盒子编号
     * @return String webrtcUrl
     */
    private BoxStreamUrlReceiver getWebrtcUrl(String boxSn) {
        BoxStreamUrlReceiver boxLiveUrl = tyService.getBoxLiveUrl(boxSn);
        boxLiveUrl.setBoxSn(boxSn);
        return boxLiveUrl;
    }
}