Working on presigned urls in local.

app/api/files/[fileName]/route.ts

@@ -0,0 +1,61 @@
+import * as fs from "node:fs";
+import {NextResponse} from "next/server";
+import path from "path";
+
+export async function GET(
+    request: Request,
+    {params}: { params: Promise<{ fileName: string }> }
+) {
+
+    // Retrieve params
+    const {searchParams} = new URL(request.url);
+    const token = searchParams.get('token');
+    const expires = searchParams.get('expires');
+    const fileName = (await params).fileName
+
+
+    const privateLocalDir = "private/uploads/";
+    const filePath = path.join(privateLocalDir, fileName);
+
+    const crypto = require('crypto');
+
+
+    if (!fs.existsSync(filePath)) {
+        return NextResponse.json(
+            {error: 'File not found'},
+            {status: 404}
+        );
+    }
+
+    const expectedToken = crypto.createHash('sha256').update(`${fileName}${expires}`).digest('hex');
+    if (token !== expectedToken) {
+        return NextResponse.json(
+            {error: 'Invalid signed token'},
+            {status: 403}
+        );
+    }
+
+    const expiresAt = parseInt(expires, 10);
+    if (Date.now() > expiresAt) {
+        return NextResponse.json(
+            {error: 'Signed token expired'},
+            {status: 403}
+        );
+    }
+
+    const fileStream = fs.createReadStream(filePath);
+    const stream = new ReadableStream({
+        start(controller) {
+            fileStream.on('data', (chunk) => controller.enqueue(chunk));
+            fileStream.on('end', () => controller.close());
+            fileStream.on('error', (err) => controller.error(err));
+        },
+    });
+
+    return new NextResponse(stream, {
+        headers: {
+            'Content-Disposition': `attachment; filename="${fileName}"`,
+            'Content-Type': 'application/octet-stream',
+        },
+    });
+}