airshipui/client/src/services/websocket/websocket.service.ts

import { Injectable } from '@angular/core';
import { WebsocketMessage } from './models/websocket-message/websocket-message';
import { Subject } from 'rxjs';
import {Dashboard} from './models/websocket-message/dashboard/dashboard';
import {Executable} from './models/websocket-message/dashboard/executable/executable';

@Injectable({
  providedIn: 'root'
})
export class WebsocketService {

  public subject = new Subject<WebsocketMessage>();
  private ws: WebSocket;
  private timeout: number;

  private static messageToObject(incomingMessage: string): WebsocketMessage {
    let json = JSON.parse(incomingMessage);
    let obj = new WebsocketMessage();

    Object.assign(obj, json);
    return obj;
  }

  constructor() {
    this.register();
  }

  public sendMessage(message: WebsocketMessage): void {
    message.timestamp = new Date().getTime();
    this.ws.send(JSON.stringify(message));
  }

  private register(): void {
    if (this.ws !== undefined && this.ws !== null) {
      this.ws.close();
      this.ws = null;
    }

    this.ws = new WebSocket('ws://localhost:8080/ws');

    this.ws.onmessage = (event) => {
      this.subject.next(WebsocketService.messageToObject(event.data));
    };

    this.ws.onerror = (event) => {
      console.log('Web Socket received an error: ', event);
    };

    this.ws.onopen = () => {
      console.log('Websocket established');
      const json = { type: 'airshipui', component: 'initialize' };
      this.ws.send(JSON.stringify(json));
      // start up the keepalive so the websocket-message stays open
      this.keepAlive();
    };

    this.ws.onclose = (event) => {
      this.close(event.code);
    };
  }

  private close(code): void {
    switch (code) {
      case 1000:
        console.log('Web Socket Closed: Normal closure: ', code);
        break;
      case 1001:
        console.log('Web Socket Closed: An endpoint is "going away", such as a server going down or a browser having navigated away from a page:', code);
        break;
      case 1002:
        console.log('Web Socket Closed: terminating the connection due to a protocol error: ', code);
        break;
      case 1003:
        console.log('Web Socket Closed: terminating the connection because it has received a type of data it cannot accept: ', code);
        break;
      case 1004:
        console.log('Web Socket Closed: Reserved. The specific meaning might be defined in the futur: ', code);
        break;
      case 1005:
        console.log('Web Socket Closed: No status code was actually present: ', code);
        break;
      case 1006:
        console.log('Web Socket Closed: The connection was closed abnormally: ', code);
        break;
      case 1007:
        console.log('Web Socket Closed: terminating the connection because it has received data within a message that was not ' +
        'consistent with the type of the message: ', code);
        break;
      case 1008:
        console.log('Web Socket Closed: terminating the connection because it has received a message that "violates its policy": ', code);
        break;
      case 1009:
        console.log('Web Socket Closed: terminating the connection because it has received a message that is too big for it to ' +
          'process: ', code);
        break;
      case 1010:
        console.log('Web Socket Closed: client is terminating the connection because it has expected the server to negotiate ' +
        'one or more extension, but the server didn\'t return them in the response message of the WebSocket handshake: ', code);
        break;
      case 1011:
        console.log('Web Socket Closed: server is terminating the connection because it encountered an unexpected condition that' +
          ' prevented it from fulfilling the request: ', code);
        break;
      case 1015:
        console.log('Web Socket Closed: closed due to a failure to perform a TLS handshake (e.g., the server certificate can\'t be' +
          ' verified): ', code);
        break;
      default:
        console.log('Web Socket Closed: unknown error code: ', code);
        break;
    }

    this.ws = null;
  }

  private keepAlive(): void {
    if (this.ws !== undefined && this.ws !== null && this.ws.readyState !== this.ws.CLOSED) {
      // clear the previously set timeout
      window.clearTimeout(this.timeout);
      window.clearInterval(this.timeout);
      const json = { type: 'airshipui', component: 'keepalive' };
      this.ws.send(JSON.stringify(json));
      this.timeout = window.setTimeout(this.keepAlive, 60000);
    }
  }
}