QRCodeText.ts

import QRCodeRaw from './QRCodeRaw';
import type { OptionsType as ParentOptionsType } from './QRCodeRaw';

export type OptionsType = ParentOptionsType & {
  blackSymbol: string;
  whiteSymbol: string;
};

const DEFAULT_OPTIONS = {
  blackSymbol: '▓▓',
  whiteSymbol: '  ',
};

export default class QRCodeText extends QRCodeRaw {
  blackSymbol: string;
  whiteSymbol: string;
  qrCodeText: string | undefined | null;

  constructor(value: string, options: Partial<OptionsType> = {}) {
    super(value, options);
    const params = { ...DEFAULT_OPTIONS, ...options };

    this.blackSymbol = params.blackSymbol;
    this.whiteSymbol = params.whiteSymbol;
  }

  _clearCache(): void {
    super._clearCache();
    this.qrCodeText = null;
  }

  toString(): null | string {
    if (this.qrCodeText) {
      return this.qrCodeText;
    }

    const dataSize = this.getDataSize();
    if (!dataSize) {
      return null;
    }

    const data = this.getData();

    // FIXME eh?
    if (data === null) {
      return null;
    }

    const symbols: string[] = [];

    for (let y = 0; y < dataSize; y += 1) {
      for (let x = 0; x < dataSize; x += 1) {
        const isBlack = data[y][x];
        symbols.push(isBlack ? this.blackSymbol : this.whiteSymbol);
      }
      symbols.push('\n');
    }
    this.qrCodeText = symbols.join('');
    return this.qrCodeText;
  }
}