subscribe.ts

import { CallbackOptions, MakeFn, SubscribeRecipe } from "../../types";
import { uniq } from "../util";

const subscriptionPath = "Device.LocalAgent.Subscription.";

const make: MakeFn =
  (call, on): SubscribeRecipe =>
  async (opts, callback) => {
    const id = "NOTIFY@" + (opts.id || uniq());
    const refList = Array.isArray(opts.reference)
      ? opts.reference.join(",")
      : opts.reference;

    const newSubPath = await call("ADD", {
      path: subscriptionPath,
      value: {
        Enable: true,
        ID: id,
        NotifType: opts.notif,
        NotifRetry: "retry" in opts ? opts.retry : true,
        ReferenceList: refList,
        Persistent: false,
      },
    });

    // from https://usp.technology/specification/07-index-messages.html#sec:responses-and-retry

    const respond = () => call("NOTIFY_RESP", { subscriptionId: id });
    const clear = on(id, (msg, fullMsg, opts) => {
      opts?.sendResp && respond();
      callback(msg, fullMsg);
    });
    return () => {
      clear();
      return call("DELETE", { paths: newSubPath });
    };
  };

export default {
  name: "subscribe",
  make,
};