From 02dfc68d68bf836abe2204f43cf56fd69dde6a84 Mon Sep 17 00:00:00 2001
From: Vrinda Bansal <50393780+VrindaBansal@users.noreply.github.com>
Date: Wed, 22 Oct 2025 08:52:03 -0700
Subject: [PATCH] Implement file upload with Redis pub/sub progress tracking

- Add Redis client for publishing progress updates
- Implement publishProgress() helper function
- Add real-time progress tracking through file-upload channel
- Simulate chunked file processing with progress updates (0-100%)
- Handle error cases with failed status publishing
- Support multer file uploads with 10MB limit
---
 routes/file-upload.ts | 89 ++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 87 insertions(+), 2 deletions(-)

diff --git a/routes/file-upload.ts b/routes/file-upload.ts
index 8ff6faf..3f96dc2 100644
--- a/routes/file-upload.ts
+++ b/routes/file-upload.ts
@@ -1,18 +1,103 @@
 import { Router } from "express";
 import type { Request, Response } from "express";
 import multer from "multer";
+import Redis from "ioredis";
+import { v4 as uuidv4 } from "uuid";
 
 const router = Router();
+const redis = new Redis(process.env.REDIS_URL || "redis://localhost:6379");
 
 // Configure multer to store files in memory by default.
 // Swap to disk storage if needed in the future.
-const upload = multer({ storage: multer.memoryStorage() });
+const upload = multer({
+  storage: multer.memoryStorage(),
+  limits: { fileSize: 10 * 1024 * 1024 }, // 10MB limit
+});
+
+/**
+ * Publish progress update to Redis
+ * @param channel - Redis channel (e.g., "file-upload", "bulk-upload")
+ * @param jobId - Unique job identifier
+ * @param data - Progress data
+ */
+async function publishProgress(
+  channel: string,
+  jobId: string,
+  data: Record<string, any>
+) {
+  const payload = {
+    jobId,
+    timestamp: Date.now(),
+    ...data,
+  };
+
+  await redis.publish(channel, JSON.stringify(payload));
+  console.log(`📡 Published to ${channel}:`, payload);
+}
 
 router.post(
   "/file-upload",
   upload.single("file"),
   async (req: Request, res: Response) => {
-    return res.status(200).json({ ok: true });
+    const file = req.file;
+    const { userId, userEmail } = req.body;
+
+    if (!file) {
+      return res.status(400).json({ error: "No file uploaded" });
+    }
+
+    const jobId = uuidv4();
+
+    try {
+      // Send initial response with jobId
+      res.status(202).json({
+        jobId,
+        message: "File upload started",
+        fileName: file.originalname,
+        fileSize: file.size,
+      });
+
+      // Publish initial progress
+      await publishProgress("file-upload", jobId, {
+        status: "processing",
+        progress: 0,
+        fileName: file.originalname,
+        fileSize: file.size,
+        userId,
+        userEmail,
+      });
+
+      // Simulate file processing (replace with actual logic)
+      for (let i = 1; i <= 10; i++) {
+        await new Promise((resolve) => setTimeout(resolve, 500));
+
+        await publishProgress("file-upload", jobId, {
+          status: "processing",
+          progress: i * 10,
+          fileName: file.originalname,
+          message: `Processing chunk ${i}/10...`,
+        });
+      }
+
+      // Final completion
+      await publishProgress("file-upload", jobId, {
+        status: "completed",
+        progress: 100,
+        fileName: file.originalname,
+        message: "File processing completed",
+      });
+
+      console.log(`✅ File upload completed: ${jobId}`);
+    } catch (error) {
+      console.error(`❌ File upload error for ${jobId}:`, error);
+
+      await publishProgress("file-upload", jobId, {
+        status: "failed",
+        progress: 0,
+        fileName: file.originalname,
+        error: error instanceof Error ? error.message : "Unknown error",
+      });
+    }
   }
 );