AriWeb-Suite/modules/webmaker/lib/xlsx.js

'use strict';
// ============================================================================
// 최소 XLSX 작성기 (의존성 없음)
// 설문 응답 등을 엑셀로 내려받을 때 쓴다. 하나의 시트, 문자열/숫자 셀만 지원하며
// 서식·수식·병합은 다루지 않는다(사용자가 엑셀에서 다시 가공하는 용도).
//
// XLSX = ZIP 컨테이너 안의 OOXML 파일들. Node 의 zlib(deflateRawSync) 로 압축하고
// ZIP 의 로컬 헤더·중앙 디렉터리·CRC32 를 직접 쓴다.
// ============================================================================
const zlib = require('zlib');

/** CRC32 (ZIP 필수) — 테이블 방식 */
const CRC_TABLE = (() => { const t = new Int32Array(256); for (let n = 0; n < 256; n++) { let c = n; for (let k = 0; k < 8; k++) c = c & 1 ? 0xEDB88320 ^ (c >>> 1) : c >>> 1; t[n] = c; } return t; })();
function crc32(buf) { let c = -1; for (let i = 0; i < buf.length; i++) c = CRC_TABLE[(c ^ buf[i]) & 0xff] ^ (c >>> 8); return (c ^ -1) >>> 0; }

/** 파일 목록 [{name, data(Buffer)}] 을 ZIP(Buffer) 으로 */
function zip(files) {
  const parts = []; const central = []; let offset = 0;
  const dosTime = (d) => ((d.getHours() << 11) | (d.getMinutes() << 5) | (d.getSeconds() >> 1)); const dosDate = (d) => (((d.getFullYear() - 1980) << 9) | ((d.getMonth() + 1) << 5) | d.getDate());
  const now = new Date();
  for (const f of files) {
    const name = Buffer.from(f.name, 'utf8'); const raw = Buffer.isBuffer(f.data) ? f.data : Buffer.from(f.data, 'utf8');
    const comp = zlib.deflateRawSync(raw); const crc = crc32(raw);
    const local = Buffer.alloc(30); local.writeUInt32LE(0x04034b50, 0); local.writeUInt16LE(20, 4); local.writeUInt16LE(0x0800, 6); local.writeUInt16LE(8, 8); local.writeUInt16LE(dosTime(now), 10); local.writeUInt16LE(dosDate(now), 12); local.writeUInt32LE(crc, 14); local.writeUInt32LE(comp.length, 18); local.writeUInt32LE(raw.length, 22); local.writeUInt16LE(name.length, 26); local.writeUInt16LE(0, 28);
    parts.push(local, name, comp);
    const cd = Buffer.alloc(46); cd.writeUInt32LE(0x02014b50, 0); cd.writeUInt16LE(20, 4); cd.writeUInt16LE(20, 6); cd.writeUInt16LE(0x0800, 8); cd.writeUInt16LE(8, 10); cd.writeUInt16LE(dosTime(now), 12); cd.writeUInt16LE(dosDate(now), 14); cd.writeUInt32LE(crc, 16); cd.writeUInt32LE(comp.length, 20); cd.writeUInt32LE(raw.length, 24); cd.writeUInt16LE(name.length, 28); cd.writeUInt16LE(0, 30); cd.writeUInt16LE(0, 32); cd.writeUInt16LE(0, 34); cd.writeUInt16LE(0, 36); cd.writeUInt32LE(0, 38); cd.writeUInt32LE(offset, 42);
    central.push(cd, name);
    offset += local.length + name.length + comp.length;
  }
  const cdBuf = Buffer.concat(central);
  const end = Buffer.alloc(22); end.writeUInt32LE(0x06054b50, 0); end.writeUInt16LE(0, 4); end.writeUInt16LE(0, 6); end.writeUInt16LE(files.length, 8); end.writeUInt16LE(files.length, 10); end.writeUInt32LE(cdBuf.length, 12); end.writeUInt32LE(offset, 16); end.writeUInt16LE(0, 20);
  return Buffer.concat([...parts, cdBuf, end]);
}

const esc = (s) => String(s).replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;').replace(/"/g, '&quot;').replace(/[\x00-\x08\x0b\x0c\x0e-\x1f]/g, '');
/** 열 번호(0부터) → 엑셀 열 문자 (A, B, …, AA) */
function colName(i) { let s = ''; i += 1; while (i > 0) { const r = (i - 1) % 26; s = String.fromCharCode(65 + r) + s; i = Math.floor((i - 1) / 26); } return s; }

/**
 * 표 데이터를 XLSX Buffer 로.
 * @param {string} sheetName  시트 이름(31자 이하, 특수문자 제외)
 * @param {Array<Array<string|number|null>>} rows  첫 행은 헤더로 간주하지 않음(호출자가 넣음)
 */
function build(sheetName, rows) {
  const name = String(sheetName || 'Sheet1').replace(/[\\/*?:[\]]/g, '').slice(0, 31) || 'Sheet1';
  const cells = rows.map((r, ri) => `<row r="${ri + 1}">` + r.map((v, ci) => {
    const ref = `${colName(ci)}${ri + 1}`;
    if (v === null || v === undefined || v === '') return '';
    if (typeof v === 'number' && Number.isFinite(v)) return `<c r="${ref}"><v>${v}</v></c>`;
    return `<c r="${ref}" t="inlineStr"><is><t xml:space="preserve">${esc(v)}</t></is></c>`;   // 공유 문자열 테이블 없이 인라인 문자열로 단순화
  }).join('') + '</row>').join('');
  const widths = rows[0] ? `<cols>${rows[0].map((_, ci) => { const w = Math.min(60, Math.max(10, ...rows.slice(0, 200).map((r) => String(r[ci] == null ? '' : r[ci]).length * 1.2))); return `<col min="${ci + 1}" max="${ci + 1}" width="${w.toFixed(1)}" customWidth="1"/>`; }).join('')}</cols>` : '';
  const sheet = `<?xml version="1.0" encoding="UTF-8" standalone="yes"?><worksheet xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main">${widths}<sheetData>${cells}</sheetData></worksheet>`;
  const workbook = `<?xml version="1.0" encoding="UTF-8" standalone="yes"?><workbook xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main" xmlns:r="http://schemas.openxmlformats.org/officeDocument/2006/relationships"><sheets><sheet name="${esc(name)}" sheetId="1" r:id="rId1"/></sheets></workbook>`;
  const wbRels = `<?xml version="1.0" encoding="UTF-8" standalone="yes"?><Relationships xmlns="http://schemas.openxmlformats.org/package/2006/relationships"><Relationship Id="rId1" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/worksheet" Target="worksheets/sheet1.xml"/></Relationships>`;
  const rels = `<?xml version="1.0" encoding="UTF-8" standalone="yes"?><Relationships xmlns="http://schemas.openxmlformats.org/package/2006/relationships"><Relationship Id="rId1" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/officeDocument" Target="xl/workbook.xml"/></Relationships>`;
  const types = `<?xml version="1.0" encoding="UTF-8" standalone="yes"?><Types xmlns="http://schemas.openxmlformats.org/package/2006/content-types"><Default Extension="rels" ContentType="application/vnd.openxmlformats-package.relationships+xml"/><Default Extension="xml" ContentType="application/xml"/><Override PartName="/xl/workbook.xml" ContentType="application/vnd.openxmlformats-officedocument.spreadsheetml.sheet.main+xml"/><Override PartName="/xl/worksheets/sheet1.xml" ContentType="application/vnd.openxmlformats-officedocument.spreadsheetml.worksheet+xml"/></Types>`;
  return zip([{ name: '[Content_Types].xml', data: types }, { name: '_rels/.rels', data: rels }, { name: 'xl/workbook.xml', data: workbook }, { name: 'xl/_rels/workbook.xml.rels', data: wbRels }, { name: 'xl/worksheets/sheet1.xml', data: sheet }]);
}

module.exports = { build, zip, crc32 };