Initial commit: Voiced invoice desktop app

Offline-first invoicing app for Test Vendor, built by Bongbetic.

- Tauri v2 (Rust) + React/TypeScript + IBM Carbon Design System UI
- SQLite (rusqlite) storage with a persistent invoice-number series
- Guided first-run setup, pre-filled vendor/bank details
- Fixed-amount or rate x quantity line items (per sec/min/hour/session/unit)
- GST as CGST+SGST or IGST, Indian amount-in-words
- Optional signature, with a computer-generated note as fallback
- Print-ready PDF export via @react-pdf/renderer
- Windows cross-compile via cargo-xwin (NSIS installer)

Co-authored-by: CommandCodeBot <noreply@commandcode.ai>

src/lib/pdf.tsx

@@ -0,0 +1,94 @@
+import { pdf } from "@react-pdf/renderer";
+import { save } from "@tauri-apps/plugin-dialog";
+import { InvoiceDocument, type InvoicePdfProps } from "../pdf/InvoiceDocument";
+import { api } from "./api";
+import type { BankAccount, Invoice, Settings } from "./types";
+
+function blobToBase64(blob: Blob): Promise<string> {
+  return new Promise((resolve, reject) => {
+    const reader = new FileReader();
+    reader.onload = () => {
+      const result = String(reader.result ?? "");
+      resolve(result.substring(result.indexOf(",") + 1));
+    };
+    reader.onerror = () => reject(reader.error);
+    reader.readAsDataURL(blob);
+  });
+}
+
+export async function buildPdfProps(
+  invoice: Invoice,
+  settings: Settings,
+  bank: BankAccount | null,
+): Promise<InvoicePdfProps> {
+  const logoDataUri = settings.logoPath ? await api.readAssetDataUri(settings.logoPath) : null;
+  const signatureDataUri = invoice.signaturePath
+    ? await api.readAssetDataUri(invoice.signaturePath)
+    : null;
+
+  let resolvedBank = bank;
+  if (!resolvedBank && invoice.bankSnapshot) {
+    try {
+      resolvedBank = JSON.parse(invoice.bankSnapshot) as BankAccount;
+    } catch {
+      resolvedBank = null;
+    }
+  }
+
+  return {
+    vendor: settings,
+    bank: resolvedBank,
+    logoDataUri,
+    signatureDataUri,
+    number: invoice.number,
+    invoiceDate: invoice.invoiceDate,
+    dueDate: invoice.dueDate,
+    clientName: invoice.clientName,
+    clientAddress: invoice.clientAddress,
+    clientGstin: invoice.clientGstin,
+    poNumber: invoice.poNumber,
+    placeOfSupplyStateCode: invoice.placeOfSupplyStateCode,
+    items: invoice.items,
+    subtotal: invoice.subtotal,
+    discount: invoice.discount,
+    taxType: invoice.taxType,
+    taxRate: invoice.taxRate,
+    cgst: invoice.cgstAmount,
+    sgst: invoice.sgstAmount,
+    igst: invoice.igstAmount,
+    total: invoice.total,
+    amountInWords: invoice.amountInWords,
+    notes: invoice.notes,
+  };
+}
+
+/** Render props straight to a PDF blob. */
+export async function renderPdfBlob(props: InvoicePdfProps): Promise<Blob> {
+  return pdf(<InvoiceDocument {...props} />).toBlob();
+}
+
+/** Render a PDF and prompt the user for a save location. */
+export async function exportPdfFromProps(
+  props: InvoicePdfProps,
+  fileName: string,
+): Promise<string | null> {
+  const blob = await renderPdfBlob(props);
+  const dataBase64 = await blobToBase64(blob);
+  const suggested = fileName.replace(/[^A-Za-z0-9._-]+/g, "-") || "invoice";
+  const path = await save({
+    defaultPath: `${suggested}.pdf`,
+    filters: [{ name: "PDF document", extensions: ["pdf"] }],
+  });
+  if (!path) return null;
+  await api.saveBinaryFile(path, dataBase64);
+  return path;
+}
+
+export async function exportInvoicePdf(
+  invoice: Invoice,
+  settings: Settings,
+  bank: BankAccount | null,
+): Promise<string | null> {
+  const props = await buildPdfProps(invoice, settings, bank);
+  return exportPdfFromProps(props, invoice.number);
+}