import { TRANSLATIONS, TRANSLATIONS_FORMAT, LOCALE_ID, MissingTranslationStrategy } from '@angular/core';
import { CompilerConfig } from '@angular/compiler';
import { Observable } from "rxjs/Rx";

export function getTranslationProviders(): Promise<Object[]> {

  // Get the locale id from the global
  const locale = document['locale'] as string;

  // return no providers if fail to get translation file for locale
  const noProviders: Object[] = [];

  // No locale or U.S. English: no translation providers
  if (!locale || locale === 'en-IN') {
    return Promise.resolve(noProviders);
  }

  // Ex: '/clari5-cc/cc/app/locale/messages.fa-IR..xliff2.xlf`
  const translationFile = `/clari5-cc/cc/app/locale/messages.${locale}.xliff2.xlf`;

  return getTranslationsWithRxjs(translationFile)
    .then( (translations: string ) => [
      { provide: TRANSLATIONS, useValue: translations },
      { provide: TRANSLATIONS_FORMAT, useValue: 'xlf2' },
      { provide: LOCALE_ID, useValue: locale },
    ])
    .catch(() => noProviders); // ignore if file not found
}

declare var System: any;
//modified as per https://stackoverflow.com/a/43369141/41284 and no longer using systemjs
function getTranslationsWithRxjs(file: string) {
// changes Start here 
  var text = "";
  var fileRequest = new XMLHttpRequest();
  fileRequest.open("GET", file, false);
  console.log("after opening fileRequest GET for " + file);
  fileRequest.onerror = function (err) {
    console.log(err);
  }
  fileRequest.onreadystatechange = function () {
    if (fileRequest.readyState === 4) {
      if (fileRequest.status === 200 || fileRequest.status == 0) {
        text = fileRequest.responseText;
      }
    }
  }
  console.log("before fileRequest send for " + file);
  fileRequest.send()
  console.log("after fileRequest send for " + file);
  var observable = Observable.of(text);
  console.log("after creating observable " + file);
  var prom = observable.toPromise();
  console.log("after creating promise " + file);
  return prom; 
}