import { Injectable } from '@angular/core';
// import { QRCodeSegment, QRCodeOptions, QRCode } from 'qrcode';
import QRCode, { QRCodeSegment, QRCodeOptions, QRCodeToDataURLOptions, QRCodeToStringOptions, QRCodeToFileOptions } from 'qrcode';
import * as stream from 'stream';

@Injectable()
export class NaQRCodeService {

  constructor() { }
  /**
   * Creates QR Code symbol and returns a qrcode object.
   */
  create(text: string | QRCodeSegment[], options: QRCodeOptions): QRCode.QRCode {
    return QRCode.create(text, options);
  }
  /**
   * Draws qr code symbol to canvas.
   */
  toCanvas(text: string | QRCodeSegment[], options?: QRCodeOptions, canvas?: HTMLCanvasElement | any): Promise<any> {
    if (canvas) {
      return QRCode.toCanvas(canvas, text, options);
    }
    return QRCode.toCanvas(text, options);
  }

  /**
   * Returns a Data URI containing a representation of the QR Code image.
   */
  toDataURL(text: string | QRCodeSegment[], options?: QRCodeToDataURLOptions, canvasElement?: HTMLCanvasElement): Promise<any> {
    if (canvasElement) {
      return QRCode.toDataURL(canvasElement, text, options);
    }
    return QRCode.toDataURL(text, options);
  }

  /**
   * Returns a string representation of the QR Code.
   * If choosen output format is svg it will returns a string containing xml code.
   */
  toString(text: string | QRCodeSegment[], options?: QRCodeToStringOptions): Promise<any> {
    return QRCode.toString(text, options);
  }

  /**
   * Saves QR Code to image file.
   * If options.type is not specified, the format will be guessed from file extension.
   * Recognized extensions are png, svg, txt.
   */
  toFile(path: string, text: string | QRCodeSegment[], options?: QRCodeToFileOptions): Promise<any> {
    return QRCode.toFile(path, text, options);
  }

  /**
   * Writes QR Code image to stream. Only works with png format for now.
   */
  toFileStream(streamW: stream.Writable, text: string | QRCodeSegment[], options?: QRCodeOptions): Promise<any> {
    return QRCode.toFileStream(streamW, text, options);
  }

}