import { Injectable, OnInit, PLATFORM_ID, Inject,InjectionToken , Optional } from '@angular/core';
import { isPlatformBrowser} from '@angular/common';
import { Http, Response, Headers, RequestOptions } from '@angular/http';
import { Observable, Subscription, BehaviorSubject } from 'rxjs/Rx';
import 'rxjs/add/operator/map';
import 'rxjs/add/operator/toPromise';

import { EnvProperties } from './env-properties';
import { DOCUMENT } from '@angular/platform-browser';

@Injectable()
export class EnvironmentSpecificService {

  public envSpecific: EnvProperties;
  public envSpecificNull: EnvProperties = null;
  testBrowser: boolean;
  private envSpecificSubject: BehaviorSubject<EnvProperties> = new BehaviorSubject<EnvProperties>(null);
  private propertiesUrl = "/assets/env-properties.json";


  private serverUrl = "http://scoobydoo.di.uoa.gr:4000";
  // private serverUrl = "https://beta.explore.openaire.eu";
  // private serverUrl = "https://beta.connect.openaire.eu";
    // private serverUrl = "https://beta.admin.connect.openaire.eu";
  constructor(private http: Http,  @Inject(PLATFORM_ID) private platformId: string) {
      this.testBrowser = isPlatformBrowser(platformId);
      if (this.testBrowser) {
          //this is only executed on the browser
      }
  }
  public loadEnvironment() {
      // Only want to do this once - if root page is revisited, it calls this again.
      if (this.envSpecific === null || this.envSpecific === undefined) {
        var location = this.propertiesUrl;
        if(typeof document == 'undefined'){
          location = this.serverUrl + this.propertiesUrl;

        }else{
          location = document.location.protocol +"//" + document.location.host+this.propertiesUrl;
        }
        console.log('Loading  '+ location);
        return this.http.get(location)
            .map((data) => data.json())
            .toPromise<EnvProperties>();
      }

      return Promise.resolve(this.envSpecificNull);
  }
  public subscribeEnvironment() {
      // Only want to do this once - if root page is revisited, it calls this again.
      if (this.envSpecific === null || this.envSpecific === undefined) {
        console.log('Loading env-properties.json');

        return this.http.get(this.propertiesUrl)
            .map((data) => data.json());

      }

      return Observable.of(this.envSpecific);
  }


  public setEnvProperties(es: EnvProperties) {
    // This has already been set so bail out.
    if (es === null || es === undefined) {
        return;
    }

    this.envSpecific = es;
    console.log(this.envSpecific);

    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);
          });
  }
}