import {Injectable} from '@angular/core';
import {BehaviorSubject} from 'rxjs/BehaviorSubject';
import 'rxjs/add/operator/map';
import {Observable} from 'rxjs/Observable';

import {CookieService} from 'ngx-cookie';

import {LoggerService} from './logger.service';
import {ApiService} from './api.service';

import {User, LogoutInfo} from '../../model/user';

@Injectable()
export class AuthService {

    private currentUserSubject = new BehaviorSubject<User>(new User());
    private isAuthenticatedSubject = new BehaviorSubject<boolean>(false);

    private userUrl: string = 'user';

    constructor(
        private cookieService: CookieService,
        private apiService: ApiService,
        private loggerService: LoggerService
    ) {}

    currentUser(): Observable<User> {
        return this.currentUserSubject.asObservable();
    }

    isAuthenticated(): Observable<boolean> {
        return this.isAuthenticatedSubject.asObservable();
    }

    setAuthentication(user: User): void {
        this.currentUserSubject.next(user);
        this.isAuthenticatedSubject.next(true);
        this.loggerService.log(`Session set for ${user.contactName}.`);
    }

    purgeAuthentication(): void {
        this.currentUserSubject.next(new User());
        this.isAuthenticatedSubject.next(false);
        this.loggerService.log('Session removed.');
    }

    populate() {

        return new Promise((resolve, reject) => {

            if (this.cookieService.get('vedrax-index-ui-csrf')) {
                let url = `${this.userUrl}/current`;
                this.apiService.get<User>(url)
                    .subscribe(
                    res => {
                        this.setAuthentication(res);
                        resolve();
                    },
                    err => {
                        this.loggerService.logObject(err);
                        this.purgeAuthentication();
                        resolve();
                    });
            } else {
                this.purgeAuthentication();
                resolve();
            }

        });

    }

    login(username: string, password: string): Observable<User> {
        let url = `${this.userUrl}/login`;
        return this.apiService.post<User>(url, {userName: username, password: password})
            .map(data => {
                this.setAuthentication(data);
                return data;
            });
    }

    logout(): Observable<LogoutInfo> {
        let url = `${this.userUrl}/logout`;
        return this.apiService.get<LogoutInfo>(url)
            .map(data => {
                this.purgeAuthentication();
                return data;
            });
    }

}