excel-worker.js

'use strict';

importScripts('xlsx.full.min.js');

function parseTime(val) {
  if (!val && val !== 0) return null;
  if (val instanceof Date) return isNaN(val) ? null : val;
  if (typeof val === 'number') {
    const d = new Date(Math.round((val - 25569) * 86400000));
    return isNaN(d) ? null : d;
  }
  if (typeof val === 'string') {
    const cleaned = val.trim().replace(/\//g, '-');
    const d = new Date(cleaned);
    return isNaN(d) ? null : d;
  }
  return null;
}

function countChars(text) {
  if (!text) return 0;
  return String(text).replace(/\s/g, '').length;
}

function parseExcelBuffer(buffer, fileName) {
  const data = new Uint8Array(buffer);
  const wb = XLSX.read(data, { type: 'array', cellDates: true, dense: false });
  const ws = wb.Sheets[wb.SheetNames[0]];
  const rows = XLSX.utils.sheet_to_json(ws, { header: 1, defval: '', raw: true });
  const info = rows[1] || [];

  const session = {
    id: fileName,
    filename: fileName,
    wxid: String(info[1] || '').trim(),
    nickname: String(info[3] || '').trim(),
    remark: String(info[5] || '').trim(),
    messages: [],
  };

  for (let i = 4; i < rows.length; i++) {
    const row = rows[i];
    if (!row || row.every(c => c === '' || c == null)) continue;
    const content = String(row[7] || '');
    session.messages.push({
      seq: row[0],
      time: parseTime(row[1]),
      senderNickname: String(row[2] || '').trim(),
      senderWxid: String(row[3] || '').trim(),
      senderRemark: String(row[4] || '').trim(),
      senderRole: String(row[5] || '').trim(),
      msgType: String(row[6] || '').trim(),
      content,
      _charCount: countChars(content),
    });
  }

  return session;
}

self.onmessage = e => {
  const { fileName, buffer } = e.data || {};
  try {
    self.postMessage({ ok: true, session: parseExcelBuffer(buffer, fileName) });
  } catch (err) {
    self.postMessage({ ok: false, error: err?.message || String(err) });
  }
};