package com.ard.tianyu.service.impl;

import com.alibaba.fastjson2.JSON;
import com.ard.common.exception.NoPermissionException;
import com.ard.common.utils.SecurityUtils;
import com.ard.tianyu.websocket.domain.ControlRequestMessage;
import com.ard.tianyu.websocket.domain.WsMessage;
import com.ard.tianyu.websocket.utils.WebSocketUtil;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Service;

import java.util.concurrent.ConcurrentHashMap;

@Service
@Slf4j
public class UavControlManager {

    // 存储每个无人机的当前控制者
    public static final ConcurrentHashMap<String, Long> droneControlMap = new ConcurrentHashMap<>();

    // 存储无人机的控制请求（用于判断哪个控制者正在等待）
    public static final ConcurrentHashMap<String, Long> controlRequestMap = new ConcurrentHashMap<>();

    // 发送通知（通过 WebSocket推送）
    public void notifyMessage(String boxSn, String action, Long controller, Long requester) {
        ControlRequestMessage controlRequestMessage = ControlRequestMessage.builder()
                .boxSn(boxSn)
                .requester(requester)
                .action(action)
                .build();
        WsMessage<ControlRequestMessage> wsMessage = new WsMessage<>("controlRequest", controlRequestMessage);
        WebSocketUtil.sendMessage(controller.toString(), JSON.toJSONString(wsMessage));
    }

    // 申请控制
    public boolean requestControl(String boxSn) {
        Long requester = SecurityUtils.getUserId();
        // 如果无人机没有控制者，直接控制
        if (droneControlMap.get(boxSn) == null) {
            droneControlMap.put(boxSn, requester);
            return true; // 控制成功
        }
        // 如果无人机已经有控制者,则发送申请给当前控制者
        Long controller = droneControlMap.get(boxSn);
        if(!controller.equals(requester)) {
            // 则将控制请求加入请求队列
            controlRequestMap.put(boxSn, requester);
            // 通知当前控制者，有新的控制请求
            notifyMessage(boxSn, "request", controller, requester);
        }
        return false; // 等待当前控制者的同意
    }

    // 处理控制请求的同意或拒绝
    public boolean handleControlResponse(String boxSn, boolean approve) {
        Long controller = SecurityUtils.getUserId();
        Long requester = controlRequestMap.get(boxSn);
        // 确保请求者是当前的控制者
        if (requester != null && !requester.equals(controller)) {
            if (approve) {
                // 同意控制，将控制权赋予请求者
                droneControlMap.put(boxSn, requester);
                notifyMessage(boxSn, "approve", requester, controller);
            } else {
                notifyMessage(boxSn, "reject", requester, controller);
            }
            // 无论同意还是拒绝，都移除控制请求
            controlRequestMap.remove(boxSn);
            return true;
        }
        return false;
    }

    // 释放控制
    public boolean releaseControl(String boxSn) {
        Long controller = droneControlMap.get(boxSn);
        if (controller != null) {
            if (controller.equals(SecurityUtils.getUserId())) {
                droneControlMap.remove(boxSn);
                return true;
            } else {
                // 当前控制者不匹配，可以记录日志或者抛出异常
                log.warn("无权限释放控制, 实际控制者是 {}", controller);
                throw new NoPermissionException("无权限释放控制, 实际控制者是 " + controller);
            }
        } else {
            // 说明无人机没有控制者
            log.warn("无人机当前 {} 没有控制者,无需释放", boxSn);
            throw new NoPermissionException("无人机" + boxSn + "当前没有控制者,无需释放");
        }
    }
}