auth-service.ts

import {Injectable} from '@angular/core';
import {FirebaseAuth, AngularFire} from "angularfire2";
import {Subject, Observable, BehaviorSubject} from "rxjs";
import {AuthInfo} from "./auth-info";

@Injectable()
export class AuthService {

    static UNKNOWN_USER = new AuthInfo(null);
    authInfo$: BehaviorSubject<AuthInfo> = new BehaviorSubject<AuthInfo>(AuthService.UNKNOWN_USER);

    constructor(public auth: FirebaseAuth,
                public af: AngularFire) {

        this.af.auth.subscribe(auth => {
            if (auth) {
                const authInfo = new AuthInfo(auth.uid);
                this.authInfo$.next(authInfo);
            }
            else {
                this.authInfo$.next(AuthService.UNKNOWN_USER);
            }
        });
    }

    login(email: string, password: string) {
        return this.fromFirebaseAuthPromise(this.auth.login({email, password}));
    }

    fromFirebaseAuthPromise(promise): Observable<any> {

        const subject = new Subject<any>();
        promise
            .then(res => {
                    subject.next(res);
                    subject.complete();
                },
                err => {
                    subject.error(err);
                    subject.complete();
                });

        return subject.asObservable();
    }

    logout() {
        this.af.auth.logout();
    }

}