typedserver/ts_web/index.ts

import * as plugins from './typedserver_web.plugins.js';
import * as interfaces from '../ts/interfaces/index.js';
import { logger } from './typedserver_web.logger.js';
logger.log('info', `TypedServer-Devtools initialized!`);

import { TypedserverInfoscreen } from './typedserver_web.infoscreen.js';

export class ReloadChecker {
  public reloadJustified = false;
  public backendConnectionLost = false;
  public infoscreen = new TypedserverInfoscreen();
  public store = new plugins.webstore.WebStore({
    dbName: 'apiglobal__typedserver',
    storeName: 'apiglobal__typedserver',
  });
  public storeKey = 'lastServerChange';

  public typedsocket: plugins.typedsocket.TypedSocket;
  public typedrouter = new plugins.typedrequest.TypedRouter();

  constructor() {}

  public async reload() {
    // this looks a bit hacky, but apparently is the safest way to really reload stuff
    window.location.reload();
  }

  /**
   * starts the reload checker
   */
  public async performHttpRequest() {
    logger.log('info', 'performing http check...');
    (await this.store.get(this.storeKey))
      ? null
      : await this.store.set(this.storeKey, globalThis.typedserver.lastReload);

    let response: Response;

    try {
      const controller = new AbortController();
      plugins.smartdelay.delayFor(5000).then(() => {
        controller.abort();
      });
      response = await fetch('/typedserver/reloadcheck', {
        method: 'POST',
        signal: controller.signal,
      });
    } catch (err: any) {}

    if (response?.status !== 200) {
      this.backendConnectionLost = true;
      logger.log('warn', `got a status ${response?.status}.`);
      this.infoscreen.setText(`backend connection lost... Status ${response?.status}`);
    }
    if (response?.status === 200 && this.backendConnectionLost) {
      this.backendConnectionLost = false;
      this.infoscreen.setSuccess('regained connection to backend...');
    }
    return response;
  }

  public async checkReload(lastServerChange: number) {
    let reloadJustified = false;
    (await this.store.get(this.storeKey)) !== lastServerChange ? (reloadJustified = true) : null;

    if (reloadJustified) {
      this.store.set(this.storeKey, lastServerChange);
      const reloadText = `about to reload ${
        globalThis.globalSw ? '(purging the sw cache first...)' : ''
      }`;
      this.infoscreen.setText(reloadText);
      if (globalThis.globalSw?.purgeCache) {
        await globalThis.globalSw.purgeCache();
      } else {
        console.log('globalThis.globalSw not found...');
      }
      this.infoscreen.setText(`cleaned caches`);
      await plugins.smartdelay.delayFor(200);
      this.reload();
      return;
    } else {
      if (this.infoscreen) {
        this.infoscreen.hide();
      }
      return;
    }
  }

  public async connectTypedsocket() {
    if (!this.typedsocket) {
      this.typedrouter.addTypedHandler<interfaces.IReq_PushLatestServerChangeTime>(
        new plugins.typedrequest.TypedHandler('pushLatestServerChangeTime', async (dataArg) => {
          this.checkReload(dataArg.time);
          return {};
        })
      );
      this.typedsocket = await plugins.typedsocket.TypedSocket.createClient(
        this.typedrouter,
        plugins.typedsocket.TypedSocket.useWindowLocationOriginUrl()
      );
      this.typedsocket.eventSubject.subscribe(eventArg => {
        console.log(`typedsocket event subscription: ${eventArg}`);
        if (eventArg === 'disconnected' || eventArg === 'disconnecting' || eventArg === 'timedOut') {
          this.backendConnectionLost = true;
          this.infoscreen.setText(`typedsocket ${eventArg}!`)
        } else if (eventArg === 'connected' && this.backendConnectionLost) {
          this.backendConnectionLost = false;
          this.infoscreen.setSuccess('typedsocket connected!')
        }

      });
      logger.log('success', `ReloadChecker connected through typedsocket!`)
    }
  }

  public started = false;
  public async start() {
    this.started = true;
    logger.log('info', `starting ReloadChecker...`);
    while (this.started) {
      const response = await this.performHttpRequest();
      if (response.status === 200) {
        logger.log('info', `ReloadChecker reached backend!`);
        await this.checkReload(parseInt(await response.text()));
        await this.connectTypedsocket();
      }
      await plugins.smartdelay.delayFor(120000);
    }
  }

  public async stop() {
    this.started = false;
  }
}

const reloadCheckInstance = new ReloadChecker();
reloadCheckInstance.start();