listener-rss/src/listener-rss.ts

import Parser from "rss-parser/index";
import { ListenerRSSInfos as ListenerInfo } from "./Models/ListenerRSSInfos";

const DEFAULT_TIMELOOP: number = 5 * 60; // default timeloop is 5 min

export class ListenerRss {
  name: string = "";
  address: string = "";
  timeloop: number = DEFAULT_TIMELOOP; // time in seconds
  customfields?: { [key: string]: string[] | string };

  // private fields
  parser: Parser | undefined = undefined;
  loopRunning: boolean = false;

  constructor(config: ListenerInfo) {
    this.setData(config);
    this.setParser();
  }

  setParser() {
    // set parser
    this.parser = new Parser(
      this.customfields !== undefined
        ? {
            customFields: {
              feed: [],
              item: Object.entries(this.customfields).map(([, value]) => {
                return Array.isArray(value) ? value[0] : value;
              }),
            },
          }
        : {}
    ); // if customfield is set -> let's set the parser with, else let the option empty
  }

  setData(infos: ListenerInfo) {
    // Set data
    this.name = infos.name;
    this.address = infos.address;
    this.timeloop =
      infos.timeloop === undefined ? DEFAULT_TIMELOOP : infos.timeloop;
    this.customfields = infos.customfields;
  }

  fetchRSS(): Promise<any> {
    // TODO Pas Bien
    if (this.parser !== undefined && this.address !== undefined) {
      return this.parser.parseURL(this.address).catch((err) => {
        throw new Error("bad address or no access : " + err);
      });
    } else throw new Error("listener must be first initialized");
  }

  /**
   * @brief call the callback function each looptime
   * @param callback function who's going to be called with the latest get
   */
  start(
    callback: (
      obj: { [key: string]: any } | undefined,
      err: Error | undefined
    ) => void
  ) {
    this.loopRunning = true;

    const fun = () => {
      this.fetchRSS()
        .then((obj: { [key: string]: any }) => callback(obj, undefined))
        .catch((err) => callback(undefined, err));
    };
    let fun_loop = () => {
      fun();
      console.log("while");
      if (this.loopRunning) setTimeout(fun_loop, this.timeloop * 1000);
    };
    fun_loop();
  }

  /**
   * @brief stop the async function
   */
  stop() {
    this.loopRunning = false;
  }
}