function doPost(e) {
  try {
    var data = JSON.parse(e.postData.contents);
    var ss = SpreadsheetApp.getActiveSpreadsheet();
    var sheetName = data.company === "au" ? "AU Invoices" : "HK Invoices";
    var taxName   = data.company === "au" ? "AU Tax Summary" : "HK Tax Summary";
    var sheet = ss.getSheetByName(sheetName);
    if (!sheet) {
      sheet = ss.insertSheet(sheetName);
      sheet.appendRow(["Doc ID","Type","Company","Client","Client Email","Date","Currency","Total","Tax/GST","Status","Saved At"]);
    }
    var docs = data.documents || [];
    if (docs.length > 0) {
      var d = docs[docs.length - 1];
      var tot = parseFloat((d.total||"0").replace(/[A-Z$,\s]/g,"")) || 0;
      var tax = parseFloat((d.gst ||"0").replace(/[A-Z$,\s]/g,"")) || 0;
      sheet.appendRow([d.id, d.type, d.company, d.client, d.clientEmail||"", d.date, d.currency||"", tot, tax, d.status, d.savedAt||""]);
    }
    var tSheet = ss.getSheetByName(taxName);
    if (!tSheet) {
      tSheet = ss.insertSheet(taxName);
      tSheet.appendRow(["Generated","Company","Total Docs","Total Revenue","Total Tax","Net Revenue"]);
    }
    var totalRev = 0, totalTax = 0;
    docs.forEach(function(d) {
      totalRev += parseFloat((d.total||"0").replace(/[A-Z$,\s]/g,"")) || 0;
      totalTax += parseFloat((d.gst ||"0").replace(/[A-Z$,\s]/g,"")) || 0;
    });
    var row = [new Date(), data.companyName, docs.length, totalRev.toFixed(2), totalTax.toFixed(2), (totalRev-totalTax).toFixed(2)];
    if (tSheet.getLastRow() < 2) { tSheet.appendRow(row); }
    else { tSheet.getRange(2,1,1,6).setValues([row]); }
    return ContentService.createTextOutput(JSON.stringify({status:"ok"})).setMimeType(ContentService.MimeType.JSON);
  } catch(err) {
    return ContentService.createTextOutput(JSON.stringify({status:"error",msg:err.toString()})).setMimeType(ContentService.MimeType.JSON);
  }
}
function doGet(e) {
  return ContentService.createTextOutput(JSON.stringify({status:"ready"})).setMimeType(ContentService.MimeType.JSON);
}