feat: import Markdown (.md) files as study documents

app/api/upload/route.ts

@@ -25,12 +25,20 @@ import {
   type PdfRejectReason,
   type PdfQualityStats,
 } from "@/lib/pdf-extract";
+import {
+  markdownToPdf,
+  MarkdownEmptyError,
+  MarkdownTooLargeError,
+} from "@/lib/md-to-pdf";
 import { ensureDocDir, pdfPath } from "@/lib/paths";
 import { getDoc, newDocId, saveDoc } from "@/lib/store";
 
 export const runtime = "nodejs";
 export const maxDuration = 60;
 
+/** Extensions we accept as Markdown and render to PDF before ingesting. */
+const MARKDOWN_EXT = /\.(md|markdown|mdown|mkd|mdwn)$/i;
+
 const SAMPLE_NAME_TO_DOC_ID: Record<string, string> = {
   anatomy: "sample-anatomy",
   physics: "sample-physics",
@@ -105,6 +113,24 @@ export async function POST(req: Request) {
       buffer = Buffer.from(await file.arrayBuffer());
       const fname = (file as unknown as { name?: string }).name;
       if (fname) filename = fname.replace(/[^a-z0-9._-]/gi, "_");
+
+      // Markdown uploads: render to a clean, text-bearing PDF up front, then
+      // fall through to the exact same extract → gate → store pipeline as any
+      // other PDF. The %PDF- sanity check below then validates the rendered
+      // bytes (pdfkit emits a 1.7 header).
+      if (MARKDOWN_EXT.test(filename)) {
+        try {
+          buffer = await markdownToPdf(buffer.toString("utf-8"));
+        } catch (e) {
+          if (e instanceof MarkdownEmptyError || e instanceof MarkdownTooLargeError) {
+            return NextResponse.json({ error: e.message }, { status: 422 });
+          }
+          return NextResponse.json(
+            { error: "This Markdown file couldn't be converted to a document." },
+            { status: 422 },
+          );
+        }
+      }
     }
   } else {
     return NextResponse.json({ error: "expected multipart/form-data" }, { status: 400 });

app/library/library-client.tsx

@@ -48,7 +48,7 @@ const FILENAME_TO_TITLE: Record<string, string> = {
 };
 
 function titleOf(filename: string): string {
-  return FILENAME_TO_TITLE[filename] ?? filename.replace(/\.pdf$/i, "");
+  return FILENAME_TO_TITLE[filename] ?? filename.replace(/\.(pdf|md|markdown|mdown|mkd|mdwn)$/i, "");
 }
 
 function humaniseAgo(ts: number): string {

app/viewer/[docId]/viewer-client.tsx

@@ -286,7 +286,7 @@ export default function ViewerClient({ docId }: { docId: string }) {
 
   const docTitle = useMemo(
     () =>
-      meta && (FILENAME_TO_TITLE[meta.filename] || meta.filename.replace(/\.pdf$/i, "")),
+      meta && (FILENAME_TO_TITLE[meta.filename] || meta.filename.replace(/\.(pdf|md|markdown|mdown|mkd|mdwn)$/i, "")),
     [meta],
   );
 

components/UploadCard.tsx

@@ -83,6 +83,10 @@ const FILENAME_TO_TITLE: Record<string, string> = {
   "chemistry.pdf": "Organic Chemistry",
 };
 
+/** A PDF, or a Markdown file we render to PDF on upload. Kept in sync with
+ *  MARKDOWN_EXT in app/api/upload/route.ts. */
+const ACCEPTED_FILE = /\.(pdf|md|markdown|mdown|mkd|mdwn)$/i;
+
 function humaniseAgo(ts: number): string {
   const dt = Date.now() - ts;
   if (dt < 5_000) return "just now";
@@ -137,8 +141,8 @@ export default function UploadCard() {
   const startUpload = useCallback(
     async (file: File) => {
       setError(null);
-      if (!file.name.toLowerCase().endsWith(".pdf")) {
-        setError("Please pick a PDF file");
+      if (!ACCEPTED_FILE.test(file.name)) {
+        setError("Please pick a PDF or Markdown (.md) file");
         return;
       }
       setBusy("upload");
@@ -203,7 +207,7 @@ export default function UploadCard() {
         <input
           ref={inputRef}
           type="file"
-          accept="application/pdf,.pdf"
+          accept="application/pdf,.pdf,text/markdown,.md,.markdown"
           className="hidden"
           onChange={(e) => {
             const f = e.target.files?.[0];
@@ -237,7 +241,7 @@ export default function UploadCard() {
             </>
           ) : (
             <>
-              <span>Drop your PDF here, or</span>
+              <span>Drop your PDF or Markdown here, or</span>
               <span className="inline-flex items-center gap-1.5 rounded-md bg-[var(--accent-600)] px-3 py-1 text-[12.5px] font-semibold text-white shadow-sm transition hover:bg-[var(--accent-700)]">
                 <Upload className="h-3.5 w-3.5" />
                 Select the file
@@ -246,7 +250,7 @@ export default function UploadCard() {
           )}
         </p>
         <p className="mt-3 text-[11.5px] text-[var(--ink-400)]">
-          Text-tagged PDFs work best. No OCR.
+          Text-based PDFs and Markdown (.md) work best. No OCR.
         </p>
       </div>
 
@@ -301,7 +305,7 @@ export default function UploadCard() {
           <div className="grid grid-cols-1 gap-3 md:grid-cols-2">
             {libraryPreview.map((d) => {
               const title =
-                FILENAME_TO_TITLE[d.filename] ?? d.filename.replace(/\.pdf$/i, "");
+                FILENAME_TO_TITLE[d.filename] ?? d.filename.replace(/\.(pdf|md|markdown|mdown|mkd|mdwn)$/i, "");
               return (
                 <Link
                   key={d.id}

lib/jobs.ts

@@ -72,7 +72,7 @@ function docTitleFromFilename(filename: string): string {
     "calculus.pdf": "Differential & Integral Calculus",
     "chemistry.pdf": "Organic Chemistry",
   };
-  return FILENAME_TO_TITLE[filename] ?? filename.replace(/\.pdf$/i, "");
+  return FILENAME_TO_TITLE[filename] ?? filename.replace(/\.(pdf|md|markdown|mdown|mkd|mdwn)$/i, "");
 }
 
 function mergeTagsFile(