invoice.js

/* invoice.js — data-driven PDF generation.
 *
 * IMPORTANT: The rendering below is a line-for-line port of the ORIGINAL
 * generate() function. Every jsPDF coordinate, font call, rounding step and
 * tax formula is preserved EXACTLY so that, for the same inputs, the produced
 * PDF is byte-identical to the original app. The only change is the source of
 * the values: a plain `data` object instead of live DOM form reads. This lets
 * live-print and history-replay share ONE rendering path.
 *
 * Depends on: jsPDF 1.5.3 (global `jsPDF`) and `drawTemplate` (from
 * template-draw.js — the vector template that replaced the background JPEG).
 *
 * data shape:
 * {
 *   invoiceNumber: string|number,
 *   invoiceDate:   "YYYY-MM-DD",     // value of an <input type="date">
 *   transport:     string,
 *   vehicle:       string,
 *   consignee:     string,           // multi-line
 *   items: [ { name, gsm, hsn, size, quantity, bundles, rate }, ... ],
 *   carriageOutward: number|string,
 *   otherCharges:    number|string,
 *   igst: bool, sgst: bool, cgst: bool,
 *   lessAdvance:     number|string
 * }
 */

// Coerce a possibly-empty/string value to a number (empty -> 0), mirroring the
// original's reliance on value="0" defaults + numeric coercion.
function _num(v) {
  var n = parseFloat(v);
  return isNaN(n) ? 0 : n;
}

/* computeTotals(data) -> summary object of NUMBERS (for saving metadata + the
 * "CHECK AMOUNT" popup). Mirrors the original arithmetic exactly, including the
 * round-to-integer step on the grand total. */
function computeTotals(data) {
  var items = data.items || [];
  var amtfinal = 0;
  var totquant = 0;
  for (var i = 0; i < items.length; i++) {
    var zz = _num(items[i].quantity);
    var yy = _num(items[i].rate);
    amtfinal = amtfinal + zz * yy;
    totquant = totquant + zz * 1;
  }
  var itemCost = amtfinal;
  var xcout = _num(data.carriageOutward);
  var xother = _num(data.otherCharges);
  amtfinal = amtfinal + xcout + xother;

  var xigst = data.igst ? parseFloat(amtfinal * 0.18) : parseFloat(0);
  var xcgst = data.cgst ? parseFloat(amtfinal * 0.09) : parseFloat(0);
  var xsgst = data.sgst ? parseFloat(amtfinal * 0.09) : parseFloat(0);

  var totTax = parseFloat(xigst + xcgst + xsgst);
  var extraCost = xcout + xother;

  // Original: toFixed(0) then re-parse to toFixed(2). Keep the integer rounding.
  var xroundtot = parseFloat(parseFloat(amtfinal + xcgst + xsgst + xigst).toFixed(0));
  var xadv = _num(data.lessAdvance);
  var gross = parseFloat((xroundtot - xadv));

  return {
    itemCost: itemCost,
    totalQuantity: totquant,
    carriageOutward: xcout,
    otherCharges: xother,
    igst: xigst,
    cgst: xcgst,
    sgst: xsgst,
    tax: totTax,
    extraCost: extraCost,
    roundedTotal: xroundtot,
    lessAdvance: xadv,
    gross: gross
  };
}

/* renderGstSummary(doc, ctx) — draws the HSN-wise GST breakdown table in the
 * empty band on the lower-left of the template (x≈10–95.5mm, y≈204.5mm down),
 * to the LEFT of the TOTAL QUANTITY column.
 *
 * WHY IN CODE (not the image): this table is DYNAMIC — its rows and amounts
 * depend on each invoice's HSN codes, taxable values and applied taxes — so it
 * cannot be baked into the static background image. It is rendered per invoice.
 *
 * RECONCILIATION: the original app taxes (itemcost + carriage + other). Here we
 * group items' taxable value by HSN and add a single FREIGHT row for
 * carriage+other, so the sum of all rows' taxable == that same base. The TOTAL
 * row therefore shows CGST / SGST / IGST amounts identical to the boxes already
 * printed on the right side of the invoice.
 *
 * Only renders when at least one GST is applied AND there is at least one item;
 * otherwise it draws nothing (so non-GST invoices are unchanged).
 */
function renderGstSummary(doc, ctx) {
  var items = ctx.items || [];
  var igstOn = ctx.igst === true;
  var cgstOn = ctx.cgst === true;
  var sgstOn = ctx.sgst === true;
  if (!(igstOn || cgstOn || sgstOn) || items.length === 0) return;

  // ---- Group item taxable value by HSN (first-seen order) ----
  var order = [];
  var groups = {};
  for (var i = 0; i < items.length; i++) {
    var hsnRaw = items[i].hsn == null ? "" : String(items[i].hsn).trim();
    var key = hsnRaw === "" ? "—" : hsnRaw; // em-dash when no HSN
    var taxable = _num(items[i].quantity) * _num(items[i].rate);
    if (!Object.prototype.hasOwnProperty.call(groups, key)) {
      groups[key] = 0;
      order.push(key);
    }
    groups[key] += taxable;
  }
  var rows = [];
  for (var k = 0; k < order.length; k++) {
    rows.push({ label: order[k], taxable: groups[order[k]] });
  }
  // Carriage + other charges share the same tax base in the original app.
  var freight = _num(ctx.carriageOutward) + _num(ctx.otherCharges);
  if (freight > 0) rows.push({ label: "FREIGHT", taxable: freight });

  var cRate = cgstOn ? 0.09 : 0;
  var sRate = sgstOn ? 0.09 : 0;
  var iRate = igstOn ? 0.18 : 0;

  // ---- Column geometry (mm) ----
  var x0 = 10, x1 = 95.5;
  var cols = [
    { key: "hsn",     x: 10,   w: 14,   align: "center", head: "HSN" },
    { key: "taxable", x: 24,   w: 18,   align: "right",  head: "TAXABLE" },
    { key: "cgst",    x: 42,   w: 11.5, align: "right",  head: "CGST" },
    { key: "sgst",    x: 53.5, w: 11.5, align: "right",  head: "SGST" },
    { key: "igst",    x: 65,   w: 11.5, align: "right",  head: "IGST" },
    { key: "taxamt",  x: 76.5, w: 19,   align: "right",  head: "TAX AMT" }
  ];

  // ---- Row/height sizing to fit the band ----
  var tableTop = 204.5;
  var bottomMax = 254;   // stay above the band's bottom border (~255.4mm)
  var titleH = 5;
  var nRows = 1 /*header*/ + rows.length + 1 /*total*/;
  var rowH = Math.min(5, (bottomMax - tableTop - titleH) / nRows);
  if (rowH < 3.4) rowH = 3.4;
  var fontSize = rowH >= 4.6 ? 6.5 : (rowH >= 4 ? 6 : 5.5);
  var gridTop = tableTop + titleH;
  var tableBottom = gridTop + nRows * rowH;

  // ---- Clear the WHOLE empty band (wipes the template's stray column
  //      dividers both under the title and below the table). We stay inside
  //      the band's outer borders: top border ≈203.5mm, bottom ≈255.4mm,
  //      left border ≈9.1mm, and the TOTAL QUANTITY separator ≈96.5mm. ----
  doc.setFillColor(255, 255, 255);
  doc.rect(x0, 204, x1 - x0, 255.2 - 204, "F");

  // ---- Frame + inner grid ----
  doc.setDrawColor(0, 0, 0);
  doc.setLineWidth(0.3);
  doc.rect(x0, tableTop, x1 - x0, titleH, "S");            // title band
  doc.rect(x0, gridTop, x1 - x0, tableBottom - gridTop, "S"); // grid frame
  doc.setLineWidth(0.2);
  for (var c = 1; c < cols.length; c++) {                  // column separators
    doc.line(cols[c].x, gridTop, cols[c].x, tableBottom);
  }
  for (var r = 1; r < nRows; r++) {                        // row separators
    var ry = gridTop + r * rowH;
    doc.line(x0, ry, x1, ry);
  }

  function put(col, text, rowTop, bold) {
    doc.setFontType(bold ? "bold" : "normal");
    var ty = rowTop + rowH * 0.68;
    if (col.align === "right") {
      doc.text(String(text), col.x + col.w - 1.5, ty, { align: "right" });
    } else {
      doc.text(String(text), col.x + col.w / 2, ty, { align: "center" });
    }
  }

  // ---- Title ----
  doc.setFontSize(7.5);
  doc.setFontType("bold");
  doc.text("GST SUMMARY (HSN-WISE)", (x0 + x1) / 2, tableTop + titleH * 0.68, {
    align: "center"
  });

  // ---- Header ----
  doc.setFontSize(fontSize);
  for (var h = 0; h < cols.length; h++) {
    doc.setFontType("bold");
    doc.text(cols[h].head, cols[h].x + cols[h].w / 2, gridTop + rowH * 0.68, {
      align: "center"
    });
  }

  // ---- Data rows ----
  var tBase = 0;
  for (var ri = 0; ri < rows.length; ri++) {
    var rowTop = gridTop + (ri + 1) * rowH;
    var base = rows[ri].taxable;
    tBase += base;
    var cg = base * cRate, sg = base * sRate, ig = base * iRate;
    put(cols[0], rows[ri].label, rowTop, false);
    put(cols[1], base.toFixed(2), rowTop, false);
    put(cols[2], cg.toFixed(2), rowTop, false);
    put(cols[3], sg.toFixed(2), rowTop, false);
    put(cols[4], ig.toFixed(2), rowTop, false);
    put(cols[5], (cg + sg + ig).toFixed(2), rowTop, false);
  }

  // ---- Total row (base*rate, so it matches the right-side tax boxes exactly) ----
  var totalTop = gridTop + (rows.length + 1) * rowH;
  var TCg = tBase * cRate, TSg = tBase * sRate, TIg = tBase * iRate;
  put(cols[0], "TOTAL", totalTop, true);
  put(cols[1], tBase.toFixed(2), totalTop, true);
  put(cols[2], TCg.toFixed(2), totalTop, true);
  put(cols[3], TSg.toFixed(2), totalTop, true);
  put(cols[4], TIg.toFixed(2), totalTop, true);
  put(cols[5], (TCg + TSg + TIg).toFixed(2), totalTop, true);

  // restore defaults the surrounding code expects
  doc.setFontSize(10);
  doc.setFontType("normal");
}

/* generateInvoice(data, doprint)
 *   doprint === true  -> save the PDF file (INVOICE_<number>.pdf)
 *   doprint !== true  -> show the CHECK AMOUNT alert only (no file)
 * Returns the computeTotals() summary so callers can persist metadata. */
function generateInvoice(data, doprint) {
  var doc = new jsPDF();
  // Draw the entire static template as vectors (frame, grid, letterhead,
  // column headers, totals labels, footer) instead of stamping a background
  // JPEG. See template-draw.js. Same visual layout, ~7.5KB not ~425KB.
  drawTemplate(doc);
  doc.setFontSize(10);
  doc.setFontType("bold");

  // ---- Invoice / consignee header (exact original coordinates) ----
  doc.text(String(data.invoiceNumber), 42, 62);

  var dte = new Date(data.invoiceDate);
  var dt = dte.getDate();
  var mn = dte.getMonth();
  mn++;
  var yy = dte.getFullYear();
  var findate = String(dt + "/" + mn + "/" + yy);
  doc.text(findate, 42, 66.3);

  doc.text(String(data.transport), 42, 70.6);
  doc.text(String(data.vehicle), 42, 74.9);

  var optionstxt = { maxWidth: "125" };
  doc.text([String(data.consignee)], 74, 66.3, optionstxt);
  doc.setFontType("normal");

  // ---- Line items ----
  optionstxt = { align: "center", maxWidth: "45" };
  var amtfinal = 0;
  var totquant = 0;
  var items = data.items || [];
  for (var sno = 0; sno < items.length; sno++) {
    var it = items[sno];
    var y = 112 + sno * 13;
    doc.text(String(sno + 1) + ".", 15, y, optionstxt);
    doc.text(String(it.name), 44, y, optionstxt);
    doc.text(String(it.hsn), 75.5, y, optionstxt);
    doc.text(String(it.gsm), 90.7, y, optionstxt);
    doc.text(String(it.size), 109.2, y, optionstxt);
    doc.text(String(it.quantity), 131.1, y, optionstxt);
    doc.text(String(it.bundles), 147, y, optionstxt);
    doc.text(String(it.rate), 164.5, y, optionstxt);
    var zz = it.quantity;
    var yy2 = it.rate;
    amtfinal = amtfinal + zz * yy2;
    totquant = totquant + zz * 1;
    var amtcur = zz * yy2;
    doc.text(String(amtcur.toFixed(2)), 187, y, optionstxt);
  }

  // ---- Totals / taxes (exact original arithmetic + coordinates) ----
  var xcgst = parseFloat(0);
  var xsgst = parseFloat(0);
  var xigst = parseFloat(0);
  var xcout = _num(data.carriageOutward);
  var itemcost = amtfinal;
  var xother = _num(data.otherCharges);
  amtfinal = amtfinal + xcout + xother;
  if (data.igst === true) xigst = parseFloat(amtfinal * 0.18);
  if (data.cgst === true) xcgst = parseFloat(amtfinal * 0.09);
  if (data.sgst === true) xsgst = parseFloat(amtfinal * 0.09);
  var totTax = parseFloat(xigst + xcgst + xsgst).toFixed(2);
  var extraCost = xcout + xother;
  var xroundtot = parseFloat(amtfinal + xcgst + xsgst + xigst);
  xroundtot = xroundtot.toFixed(0);
  xroundtot = parseFloat(xroundtot).toFixed(2);
  var xadv = _num(data.lessAdvance);
  var gross = parseFloat((xroundtot - xadv)).toFixed(2);

  doc.text(String(parseFloat(totquant).toFixed(3)), 131.1, 208, optionstxt);
  doc.text(String(xcout.toFixed(2)), 187, 208, optionstxt);
  doc.text(String(xsgst.toFixed(2)), 187, 224, optionstxt);
  doc.text(String(xcgst.toFixed(2)), 187, 230.5, optionstxt);
  doc.text(String(xigst.toFixed(2)), 187, 236.5, optionstxt);
  doc.text(String(xother.toFixed(2)), 187, 216.5, optionstxt);
  doc.text(String(xroundtot), 187, 245, optionstxt);
  doc.text(String(xadv.toFixed(2)), 187, 253.5, optionstxt);
  doc.setFontType("bold");
  doc.text(String(gross), 187, 263, optionstxt);

  // ---- HSN-wise GST summary table (dynamic; lower-left empty band) ----
  renderGstSummary(doc, {
    items: items,
    carriageOutward: data.carriageOutward,
    otherCharges: data.otherCharges,
    igst: data.igst === true,
    cgst: data.cgst === true,
    sgst: data.sgst === true
  });

  if (doprint === true) {
    doc.save('INVOICE_' + data.invoiceNumber + '.pdf');
  } else {
    alert(
      "\n----------------------------" +
      "\nITEM COST: " + itemcost.toFixed(2) +
      "\nEXTRA COST: " + extraCost.toFixed(2) +
      "\nTAX: " + totTax +
      "\nADV PROVIDED: " + xadv.toFixed(2) +
      "\n----------------------------" +
      "\nFINAL AMOUNT: " + gross +
      "\n----------------------------"
    );
  }

  return computeTotals(data);
}