import { Injectable, Injector } from '@angular/core';
import { AuthenticationService } from '../services/authentication.service';
import { MessagesService } from '../services/messages.service';
import * as moment from 'moment';

@Injectable()
export class SessionTimer {

    private intervalID: any;
    private interval: number;

    constructor(private injector: Injector) {
        this.interval = 600000; // 30 minutes session are 1 800 000 milliseconds
    }

    public startTimer(): void {
        console.log('Timer start. Next session out at ' + moment().add(10, 'minutes').format('HH:mm:ss'));
        this.intervalID = setInterval(() => {
            this.onSessionEnd();
        }, this.interval);
    }

    public resetTimer(): void {
        console.log('Timer reset at ' + moment().format('HH:mm'));
        this.stopTimer();
        this.startTimer();
    }

    public stopTimer(): void {
        clearInterval(this.intervalID);
    }

    private onSessionEnd(): void {
        let authService = this.authService;
        this.resetTimer();
        if (authService.getAccessToken() !== null) {
            authService.logout({
                onSuccess: () => {
                    this.messagesService.setWarningMessage(['Your session has expired. Please log in again.']);
                    authService.clearSession();
                }
            })
        }
    }

    private get authService(): AuthenticationService {
        return this.injector.get(AuthenticationService);
    }

    private get messagesService(): MessagesService {
        return this.injector.get(MessagesService);
    }

}