import { Injectable } from '@angular/core';
import { Observer, Observable } from 'rxjs';

/**
 * GeolocationService class.
 * https://developers.google.com/maps/documentation/javascript/
 * https://dev.w3.org/geo/api/spec-source.html
 */
@Injectable()
export class GeolocationService {

  /**
   * Tries HTML5 geolocation.
   *
   * Wraps the Geolocation API into an observable.
   *
   * @return An observable of Position
   */
  getCurrentPosition(): Observable<Position> {
    return Observable.create((observer: Observer<Position>) => {
      // Invokes getCurrentPosition method of Geolocation API.
      navigator.geolocation.watchPosition(
        (position: Position) => {
          observer.next(position);
        },
        (error: PositionError) => {
          console.debug('Geolocation service: ' + error.message);
          //observer.error(error);
        },
        {
          enableHighAccuracy: true,
          timeout: 5000,
          maximumAge: 0
        }
      );
    });
  }

}