import getMode from "../tools/getMode";
import mergeDeep from "../tools/merge";
import downloadURI from "../tools/downloadURI";
import QRCanvas from "./QRCanvas";
import defaultOptions, { type Options, type RequiredOptions } from "./QROptions";
import sanitizeOptions from "../tools/sanitizeOptions";
import type { Extension, QRCode } from "../types";
import * as qr from "qrcode-generator";

type DownloadOptions = {
  name?: string;
  extension?: Extension;
};

export default class QRCodeStyling {
  _options: RequiredOptions;
  _container?: HTMLElement;
  _canvas?: QRCanvas;
  _qr?: QRCode;
  _drawingPromise?: Promise<void>;

  constructor(options?: Partial<Options>) {
    this._options = options ? sanitizeOptions(mergeDeep(defaultOptions, options) as RequiredOptions) : defaultOptions;
    this.update();
  }

  static _clearContainer(container?: HTMLElement): void {
    if (container) {
      container.innerHTML = "";
    }
  }

  update(options?: Partial<Options>): void {
    QRCodeStyling._clearContainer(this._container);
    this._options = options ? sanitizeOptions(mergeDeep(this._options, options) as RequiredOptions) : this._options;

    if (!this._options.data) {
      return;
    }

    this._qr = <QRCode>qr.default(this._options.qrOptions.typeNumber, this._options.qrOptions.errorCorrectionLevel);
    this._qr.addData(this._options.data, this._options.qrOptions.mode || getMode(this._options.data));
    this._qr.make();
    this._canvas = new QRCanvas(this._options);
    this._drawingPromise = this._canvas.drawQR(this._qr);
    this.append(this._container);
  }

  append(container?: HTMLElement): void {
    if (!container) {
      return;
    }

    if (typeof container.appendChild !== "function") {
      // eslint-disable-next-line no-throw-literal
      throw "Container should be a single DOM node";
    }

    if (this._canvas) {
      container.appendChild(this._canvas.getCanvas());
    }

    this._container = container;
  }

  async getImageUrl(extension: string): Promise<string> {
    if (!this._drawingPromise) return "";

    const getImageUrl = await this._drawingPromise;
    if (getImageUrl === undefined) {
      if (!this._canvas) return "";
      const data = this._canvas.getCanvas().toDataURL(`image/${extension}`);
      return data;
    }
    return "";
  }

  download(downloadOptions?: Partial<DownloadOptions>): void {
    if (!this._drawingPromise) return;

    void this._drawingPromise.then(() => {
      if (!this._canvas) return;
      const opt = <DownloadOptions>downloadOptions;
      const extension = opt.extension || "png";
      const name = opt.name || "qr";
      const data = this._canvas.getCanvas().toDataURL(`image/${extension}`);
      downloadURI(data, `${name}.${extension}`);
    });
  }
}