import { Component } from '@angular/core';
import { AlertController, NavController, NavParams, ToastController } from 'ionic-angular';
import { QrScannerProvider } from '../../providers/qr-scanner/qr-scanner';
import 'rxjs/add/operator/mergeMap';
import { QRScanner, QRScannerStatus } from '@ionic-native/qr-scanner';
import { Observable } from 'rxjs/Observable';
import { SuperTabsController } from 'ionic2-super-tabs';
import { ToastProvider } from '../../providers/toast/toast';
import { fromPromise } from 'rxjs/observable/fromPromise';
import { Observer } from 'rxjs/Observer';

@Component({
  selector: 'page-qr-scanner',
  templateUrl: 'qr-scanner.html',
})
export class QrScannerPage {
  private isScanning: boolean = false;

  constructor(public navCtrl: NavController,
              public navParams: NavParams,
              private qrScanner: QrScannerProvider,
              private toastProvider: ToastProvider,
              private alertCtrl: AlertController) {
  }

  ionViewDidEnter() {
    this.showPermissionAlert().flatMap(_ => {
      return this.qrScanner.prepare();
    }).flatMap((status: QRScannerStatus) => {
      if (status.denied) {
        return Observable.throw("unauthorized")
      }
      if (status.authorized) {
        this.isScanning = true;
        return this.qrScanner.startScanning();
      }
    }).subscribe(this.handleSuccess.bind(this), this.handleError.bind(this));
  }

  private handleError(error: string) {
    switch (error) {
      case 'cordova_not_available':
        this.toastProvider.showToast("NOT_ON_MOBILE_ERROR");
        break;
    }
    if (error == "cordova_not_available") {

    }
  }

  private handleSuccess(data: string) {
    alert(data);
  }

  private showPermissionAlert(): Observable<any> {
    return Observable.create((observer: Observer<boolean>) => {
      let alert = this.alertCtrl.create({
        title: 'Camera permission',
        subTitle: 'Please press allow at the upcoming popup to allow Shorty to use your camera',
        buttons: [
          {
            text: "Got it!",
            handler: _ => {
              observer.next(true);
              observer.complete();
            }
          }
        ]
      });
      alert.present();
    });
  }
}