/*

作者：小白脸
版本：2.10
日期：2023.08.10 13:26

Surge配置参考注释

Apple下载示例↓↓↓ 
----------------------------------------

[Rule]
AND,((DOMAIN,iosapps.itunes.apple.com), (SCRIPT,策略优选)),Apple

[Script]
策略优选 = type=rule,timeout=60,script-path=https://raw.githubusercontent.com/githubdulong/Script/master/speedLimit.js,argument="Return=10min,Group=Apple&policy=DIRECT,PROXY,Support&time=15&minSpeed=20"

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• 支持监控多个策略组，每个策略组可以监控多个域名，and 套 or 规则 or 可以放多个域名 and最下面放脚本规则；
• Group 填 "策略组"是填策略组重要事情说3遍；
• policy填 "策略" 第一个是填默认策略，默认策略可以是DIRECT，可以是其他策略，后面填你要跳转的策略，多个用英文的逗号 , 隔开；
• 默认策略可以只填一个，表示循环跳转这个策略组的所有策略；
• Return 表示策略组返回默认策略时间，单位可以定义 ms s min h 表示 毫秒 秒 分钟 小时；
• time 表示要监控的时间，单位为秒；
• minSpeed 表示低于这个速度就会触发跳转策略，单位MB/s；
• 兼容了16以下的系统；
• 多策略跳转顺序就是你填的顺序；
• 只到速度达标或策略跳转完结束,Return设定的时间后自动跳转默认策略；
• 如果所有策略轮询后都未达到监控需求则自动选择记录中最优策略；

----------------------------------------
*/

const api = (p) => new Promise(r => $httpAPI("GET", p, null, d => r(d)));

const policyGroupName = (Group, policyStrategies = "decisions") => {
   return $surge.selectGroupDetails()[policyStrategies][Group];
};

const tomilli = (String = $argument) => {
   const obj = {
      ms: 1,
      s: 1000,
      min: 60 * 1000,
      h: 60 * 60 * 1000,
   };
   const [, num, unit] = String.match(/([\d\.]+)(ms|s|min|h)/) || [, "1", "h"];
   return num * obj[unit];
};

async function speed(include = "inCurrentSpeed") {
   const arr = (requests,include2) => requests
      .filter((item) => item.URL.includes(host))
      .reduce((prev, current) => (prev[include2] > current[include2] ? prev : current));
   try {
      const { requests } = await api("/v1/requests/active");
			 $persistentStore.write(JSON.stringify(requests), "kkk")
      const { [include]: result, method } = arr(requests,"inCurrentSpeed");
      return /TCP|POST|UDP/.test(method) ? result : "Nomedia";
			
			
			
			
   } catch (err) {
      const { requests } = await api("/v1/requests/recent");
      const {inMaxSpeed} = arr(requests,"inMaxSpeed");
      if (inMaxSpeed === 0) return "break";
      else throw "";
   }
}

const speed_unit = (speed) => {
   for (units of ["B/s", "KB/s", "MB/s", "GB/s", "TB/s"]) {
      if (speed < 1000 || !(speed = parseFloat(speed / 1024))) return `${speed.toFixed(2)} ${units}`;
   }
};

const write = (num, obj = {}) => {
   const targetObj = num ? cache : JSON.parse($persistentStore.read("last_update_time") || "{}");
   const _obj = { [host]: num, ...obj };
   Object.keys(_obj).forEach((key) => (targetObj[Group][key] = _obj[key]));
   return $persistentStore.write(JSON.stringify(targetObj), "last_update_time");
};

const findParentKey = (obj, value) => {
   for (let key in obj) {
      if (obj[key].hasOwnProperty(value)) return key;
   }
   return null;
};

const startTime = async (_policy0, lastUpdateTime) => {
   const data = api("v1/traffic");
   const { startTime } = data;
   const { _startTime_ } = cache;
   const bool = startTime == _startTime_;
   if (bool) {
      if (Group && _policy0 && Date.now() - lastUpdateTime >= tomilli()) {
         if (policyGroupName(Group) !== _policy0 || cache[Group]?.mix?.mix_end)
            $surge.setSelectGroupPolicy(Group, _policy0), fn();
      }
   } else {
      cache._startTime_ = startTime;
      fn();
   }


   function fn() {
      Object.entries(cache).forEach(([key, value]) => {
         if (bool ? key === Group : key !== "_startTime_") {
            Object.keys(value).forEach((prop) => {
               if (prop !== "policy0" && prop !== "time") {
                  value[prop] = 0;
               }
            });
         }
      });
   }

};

const mixspeed = (speed, policy) => {
   const mix = cache[Group]?.mix || {};
   mix.mix_speed ??= 0;
   return speed > mix.mix_speed
      ? {
         mix_speed: speed,
         mix_policy: policy,
         mix_end: false,
      }
      : mix;
};

const parameters = (arg, obj = {}) => {
   arg.split("&").forEach((value, index) => {
      const [key, val] = value.split("=");
      if (!val) throw new Error(`${key} 不能为空`);
      obj[key] = val;
   });
   return obj;
};

const optimizePolicyCode = (policy, Group) => policy
   ? policy.split(",").filter((x) => !!x)
   : policyGroupName(Group, "groups");


const findArg = async (G, isFound) => {
   let args = $argument.match(`=${G}.+?minSpeed=[0-9]+`);

   if (args) {
      return args[0].replace(/\s+/g, "");
   } else if (isFound) {
      throw new Error("策略组匹配失败,不要加空格什么的");
   }

   const parent = (await speed("notes")).find((x) => x.includes("->"));

   if (!parent) throw new Error("Group策略组不存在");

   Group = parent.match(/path\:\s(.+?)\s->/)[1];

   if (G in cache) {
      cache[Group] = cache[G];
      delete cache[G];
   }

   return await findArg(Group, true);
};

const cache = JSON.parse($persistentStore.read("last_update_time") || "{}");

const host = $request.hostname || $request.url;

let Group = findParentKey(cache, host);

const lastUpdateTime = cache[Group]?.time ?? 0;

const _policy0 = cache[Group]?.policy0;

(async () => {
   await startTime(_policy0, lastUpdateTime);
   $done({ matched: true });

   // 主逻辑循环
   try {
      // 获取参数并确定当前所在的策略组
      const arg = await findArg(Group);
      // 初始化缓存对象
      cache[Group] ||= {};

      // 检查是否存在正在处理的请求
      if (cache[Group]?.[host]) return;
      // 标记当前请求正在处理中
      write(1);

      // 解析参数,校验参数
      const { policy, time, minSpeed } = parameters(arg);
      // 对策略进行优化处理
      const arr_policy = optimizePolicyCode(policy, Group);
      // 获取默认策略
      const policy0 = arr_policy[0];
      if (_policy0 && policy0 !== _policy0) {
         cache[Group].policy0 = policy0;
         $surge.setSelectGroupPolicy(`${Group}`, policy0);
      }
      // 获取当前使用的策略
      const policy1 = policyGroupName(Group);
      // 获取当前循环speed最快策略和结束条件
      const { mix_end, mix_policy } = cache[Group].mix || {};
      // 判断是否达到结束循环条件
      const End = mix_end && policy1 === mix_policy;

      let current_speed;

      // 循环监测下载速度和策略切换条件
      for (let i = 0; i < Math.ceil(time / 3); i++) {
         // 等待3秒
         await new Promise((r) => setTimeout(r, 3000));
         // 获取当前下载速度
         current_speed = await speed();

         //判断请求方法
         if (typeof current_speed === "string") {
            if (current_speed === "break") {
               current_speed = 0;
               break;
            }
            throw "";
         }

         //结束循环条件
         if ((End || current_speed >= minSpeed * 1048576) && write(0)) return;
      }
      //记录当前最快策略信息
      const Endjson = mixspeed(current_speed, policy1);
      // 计算下一个要切换的策略，如果策略循环结束未达到条件则退回速度最快的策略并结束循环

      const p = arr_policy[arr_policy.indexOf(policy1) + 1] || ((Endjson.mix_end = true), Endjson.mix_policy);

      // 执行策略切换
      if (p !== policy1) {
      if ($surge.setSelectGroupPolicy(`${Group}`, `${p}`))
         $notification.post(
      `策略切换成功 🎉`,
      `速度 ➟ ${speed_unit(current_speed)} ➟ ${minSpeed} MB/s`,
      `域名 ${host}\n监控时长${time}秒 切换${p}策略`,
         );
	   else throw `${p}在策略组中不存在`;
      }

      // 更新缓存信息
      write(0, {
         time: Date.now(),
         policy0: policy0,
         mix: Endjson,
      });
   } catch (err) {
      // 处理错误情况
      write(0)
      err && $notification.post("错误:", "策略切换失败", `${err.message}\n${err.stack}`);
   }
})();