Add local repo contents

backend/src/lib/convert.ts

@@ -0,0 +1,59 @@
+import { promisify } from "util";
+import JSZip from "jszip";
+
+let _convert:
+  | ((buf: Buffer, ext: string, filter: undefined) => Promise<Buffer>)
+  | null = null;
+
+async function getConvert() {
+  if (!_convert) {
+    const libre = await import("libreoffice-convert");
+    _convert = promisify(libre.default.convert.bind(libre.default));
+  }
+  return _convert;
+}
+
+/**
+ * Some older Windows/Word archives store .docx entries with backslash
+ * separators (e.g. `word\document.xml`). Mammoth and LibreOffice both look
+ * up entries by exact string and miss those files, producing empty output
+ * or conversion failures. Rewrite any such entries to the canonical
+ * forward-slash form before handing the buffer off.
+ */
+export async function normalizeDocxZipPaths(buffer: Buffer): Promise<Buffer> {
+  let zip: JSZip;
+  try {
+    zip = await JSZip.loadAsync(buffer);
+  } catch {
+    return buffer;
+  }
+  const renames: [string, string][] = [];
+  zip.forEach((relativePath) => {
+    if (relativePath.includes("\\")) {
+      renames.push([relativePath, relativePath.replace(/\\/g, "/")]);
+    }
+  });
+  if (renames.length === 0) return buffer;
+  for (const [oldPath, newPath] of renames) {
+    const entry = zip.file(oldPath);
+    if (!entry) continue;
+    const content = await entry.async("nodebuffer");
+    zip.remove(oldPath);
+    zip.file(newPath, content);
+  }
+  return zip.generateAsync({ type: "nodebuffer" });
+}
+
+/**
+ * Convert a DOCX/DOC buffer to PDF using LibreOffice.
+ * Throws if LibreOffice is not installed or conversion fails.
+ */
+export async function docxToPdf(buffer: Buffer): Promise<Buffer> {
+  const convert = await getConvert();
+  const normalized = await normalizeDocxZipPaths(buffer);
+  return convert(normalized, ".pdf", undefined);
+}
+
+export function convertedPdfKey(userId: string, docId: string): string {
+  return `converted-pdfs/${userId}/${docId}.pdf`;
+}