D-Net

import {Inject, Injectable, Optional} from '@angular/core';

import {HttpClient} from "@angular/common/http";

import {BehaviorSubject, of} from 'rxjs';

import {Request} from 'express';

import {REQUEST} from '@nguniversal/express-engine/tokens';

import {EnvProperties} from './env-properties';

import {properties} from "../../../../environments/environment";

@Injectable()

export class EnvironmentSpecificService {

  public envSpecific: EnvProperties;

  public domain: string;

  private envSpecificSubject: BehaviorSubject<EnvProperties> = new BehaviorSubject<EnvProperties>(null);

  private propertiesPath = "/assets/env-properties.json?v=2";

  constructor(private http: HttpClient, @Optional() @Inject(REQUEST) private request: Request) {

    properties.domain = this.getDomain();

  }

  public loadEnvironment() {

    this.envSpecific = properties;

    return Promise.resolve(this.envSpecific);

  }

  public subscribeEnvironment() {

    // Only want to do this once - if root page is revisited, it calls this again.

    if (this.envSpecific === null || this.envSpecific === undefined) {

      this.envSpecific = properties;

    }

    // console.log('subscribeEnvironment: already loaded  ');

    return of(this.envSpecific);

  }

  getDomain() {

    var domain = "";

    if (typeof document == 'undefined') {

      domain = this.request.get('host').split(":")[0];

    } else {

      domain = document.location.hostname;

    }

    return domain;

  }

  public setEnvProperties(es: EnvProperties) {

    // This has already been set so bail out.

    if (es === null || es === undefined) {

      return;

    }

    this.envSpecific = es;

    if (this.envSpecificSubject) {

      this.envSpecificSubject.next(this.envSpecific);

    }

  }

  /*

    Call this if you want to know when EnvProperties is set.

  */

  public subscribe(caller: any, callback: (caller: any, es: EnvProperties) => void) {

    this.envSpecificSubject

      .subscribe((es) => {

        if (es === null) {

          return;

        }

        callback(caller, es);

      });

  }

}