@nuintun/qrcode/esm/encoder/Encoder.js

A pure JavaScript QRCode encode and decode library.

/**
 * @module QRCode
 * @package @nuintun/qrcode
 * @license MIT
 * @version 5.0.2
 * @author nuintun <nuintun@qq.com>
 * @description A pure JavaScript QRCode encode and decode library.
 * @see https://github.com/nuintun/qrcode#readme
 */

import {
  getSegmentLength,
  appendECI,
  appendFNC1Info,
  appendModeInfo,
  isHanziMode,
  chooseRecommendVersion,
  calculateBitsNeeded,
  willFit,
  appendLengthInfo,
  appendTerminator,
  injectECCodewords,
  chooseBestMaskAndMatrix
} from './utils/encoder.js';
import { Encoded } from './Encoded.js';
import { Charset } from '../common/Charset.js';
import { ECLevel } from '../common/ECLevel.js';
import { BitArray } from '../common/BitArray.js';
import { VERSIONS } from '../common/Version.js';
import { encode } from '../common/encoding/index.js';
import { assertHints, assertLevel, assertVersion } from './utils/asserts.js';

/**
 * @module Encoder
 */
class Encoder {
  #hints;
  #level;
  #encode;
  #version;
  /**
   * @constructor
   * @param options The options of encoder.
   */
  constructor({ hints = {}, level = 'L', version = 'Auto', encode: encode$1 = encode } = {}) {
    assertHints(hints);
    assertLevel(level);
    assertVersion(version);
    this.#hints = hints;
    this.#encode = encode$1;
    this.#version = version;
    this.#level = ECLevel[level];
  }
  /**
   * @method encode
   * @description Encode the segments.
   * @param segments The segments.
   */
  encode(...segments) {
    const ecLevel = this.#level;
    const encode = this.#encode;
    const { fnc1 } = this.#hints;
    const versionNumber = this.#version;
    const segmentBlocks = [];
    // Only append FNC1 once.
    let isFNC1Appended = false;
    // Current ECI value.
    let [currentECIValue] = Charset.ISO_8859_1.values;
    // Init segments.
    for (const segment of segments) {
      const { mode } = segment;
      const head = new BitArray();
      const body = segment.encode(encode);
      const length = getSegmentLength(segment, body);
      // Append ECI segment if applicable.
      currentECIValue = appendECI(head, segment, currentECIValue);
      // Append FNC1 if applicable.
      if (fnc1 != null && !isFNC1Appended) {
        isFNC1Appended = true;
        appendFNC1Info(head, fnc1);
      }
      // With ECI in place, Write the mode marker.
      appendModeInfo(head, mode);
      // If is Hanzi mode append GB2312 subset.
      if (isHanziMode(segment)) {
        head.append(1, 4);
      }
      // Push segment block.
      segmentBlocks.push({ mode, head, body, length });
    }
    let version;
    if (versionNumber === 'Auto') {
      version = chooseRecommendVersion(segmentBlocks, ecLevel);
    } else {
      version = VERSIONS[versionNumber - 1];
      const bitsNeeded = calculateBitsNeeded(segmentBlocks, version);
      if (!willFit(bitsNeeded, version, ecLevel)) {
        throw new Error('data too big for requested version');
      }
    }
    const buffer = new BitArray();
    for (const { mode, head, body, length } of segmentBlocks) {
      buffer.append(head);
      appendLengthInfo(buffer, mode, version, length);
      buffer.append(body);
    }
    const ecBlocks = version.getECBlocks(ecLevel);
    appendTerminator(buffer, ecBlocks.numTotalDataCodewords);
    const codewords = injectECCodewords(buffer, ecBlocks);
    const [mask, matrix] = chooseBestMaskAndMatrix(codewords, version, ecLevel);
    return new Encoded(matrix, version, ecLevel, mask);
  }
}

export { Encoder };