// 用 JS 复现 XlsxReader 的 ZIP/XML 解析逻辑，验证对真实 导入模板.xlsx 的处理
const fs = require('fs');

function u16(d, o) { const s = d.subarray(o, o + 2); return s.length < 2 ? 0 : s.readUInt16LE(0); }
function u32(d, o) { const s = d.subarray(o, o + 4); return s.length < 4 ? 0 : s.readUInt32LE(0); }

function parseZipRaw(data) {
  let eocd = -1;
  for (let i = data.length - 22; i >= 0; i--) {
    if (data[i] === 0x50 && data[i + 1] === 0x4b && data[i + 2] === 0x05 && data[i + 3] === 0x06) { eocd = i; break; }
  }
  if (eocd < 0) throw new Error('no EOCD');
  const count = u16(data, eocd + 10);
  const offset = u32(data, eocd + 16);
  const out = {};
  let p = offset;
  for (let i = 0; i < count; i++) {
    if (!(data[p] === 0x50 && data[p + 1] === 0x4b && data[p + 2] === 0x01 && data[p + 3] === 0x02)) break;
    const method = u16(data, p + 10);
    const compSize = u32(data, p + 20);
    const nameLen = u16(data, p + 28);
    const extraLen = u16(data, p + 30);
    const commentLen = u16(data, p + 32);
    const localOff = u32(data, p + 42);
    const name = data.subarray(p + 46, p + 46 + nameLen).toString('binary');
    const lNameLen = u16(data, localOff + 26);
    const lExtraLen = u16(data, localOff + 28);
    const start = localOff + 30 + lNameLen + lExtraLen;
    const raw = data.subarray(start, start + compSize);
    let content;
    if (method === 0) content = raw;
    else content = require('zlib').inflateRawSync(raw);
    out[name.replace(/\\/g, '/')] = content.toString('utf8');
    p += 46 + nameLen + extraLen + commentLen;
  }
  return out;
}

function decodeEntities(s) {
  return s.replace(/&lt;/g, '<').replace(/&gt;/g, '>').replace(/&quot;/g, '"')
    .replace(/&#39;/g, "'").replace(/&apos;/g, "'").replace(/&amp;/g, '&');
}

function parseSharedStrings(xml) {
  const out = [];
  const re = /<si>([\s\S]*?)<\/si>/g;
  let m;
  while ((m = re.exec(xml))) {
    const si = m[1];
    const tre = /<t[^>]*>([\s\S]*?)<\/t>/g;
    let t, parts = [];
    while ((t = tre.exec(si))) parts.push(decodeEntities(t[1]));
    out.push(parts.join(''));
  }
  return out;
}

function colToIndex(letters) {
  let n = 0;
  for (let i = 0; i < letters.length; i++) n = n * 26 + (letters.charCodeAt(i) - 64);
  return n - 1;
}

function parseSheet(xml, shared) {
  const rows = [];
  const rowRe = /<row\b[^>]*>([\s\S]*?)<\/row>/g;
  let rm;
  while ((rm = rowRe.exec(xml))) {
    const rowXml = rm[1];
    const cells = {};
    const cRe = /<c(?:\s([^>]*?))?(?:\/>|>([\s\S]*?)<\/c>)/g;
    let cm, autoIdx = 0;
    while ((cm = cRe.exec(rowXml))) {
      const attrs = cm[1] || '';
      const inner = cm[2] || '';
      let idx = autoIdx;
      const r = /\br="([A-Z]+)\d*"/.exec(attrs);
      if (r) idx = colToIndex(r[1]);
      autoIdx = idx + 1;
      const tm = /\bt="([^"]+)"/.exec(attrs);
      const type = tm ? tm[1] : '';
      let val = '';
      if (type === 'inlineStr') {
        const tre = /<t[^>]*>([\s\S]*?)<\/t>/g;
        let t, parts = [];
        while ((t = tre.exec(inner))) parts.push(decodeEntities(t[1]));
        val = parts.join('');
      } else {
        const vm = /<v>([\s\S]*?)<\/v>/.exec(inner);
        val = vm ? decodeEntities(vm[1]) : '';
        if (type === 's') val = shared[parseInt(val, 10)] || '';
        else if (type === 'b') val = parseInt(val, 10) === 1 ? 'TRUE' : 'FALSE';
      }
      cells[idx] = val;
    }
    const keys = Object.keys(cells).map(Number);
    if (!keys.length) continue;
    const max = Math.max(...keys);
    const line = [];
    for (let i = 0; i <= max; i++) line.push(cells[i] || '');
    rows.push(line);
  }
  return rows;
}

const file = process.argv[2];
const entries = parseZipRaw(fs.readFileSync(file));
console.log('entries:', Object.keys(entries).join(', '));
const shared = entries['xl/sharedStrings.xml'] ? parseSharedStrings(entries['xl/sharedStrings.xml']) : [];
const sheet = entries['xl/worksheets/sheet1.xml'] || entries[Object.keys(entries).find(k => /^xl\/worksheets\/sheet\d+\.xml$/.test(k))];
const rows = parseSheet(sheet, shared);
console.log('rows:', rows.length);
console.log('first 3:', JSON.stringify(rows.slice(0, 3), null, 0));
console.log('last 2:', JSON.stringify(rows.slice(-2), null, 0));