@nuintun/qrcode/cjs/encoder/Encoder.cjs

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
 */

'use strict';

const encoder = require('./utils/encoder.cjs');
const Encoded = require('./Encoded.cjs');
const Charset = require('../common/Charset.cjs');
const ECLevel = require('../common/ECLevel.cjs');
const BitArray = require('../common/BitArray.cjs');
const Version = require('../common/Version.cjs');
const index = require('../common/encoding/index.cjs');
const asserts = require('./utils/asserts.cjs');

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

exports.Encoder = Encoder;