feat: add daily cron job to mark expired invoices as overdue

backend/package.json

@@ -35,6 +35,7 @@
     "mongoose-autopopulate": "^1.1.0",
     "multer": "^1.4.4",
     "node-cache": "^5.1.2",
+    "node-cron": "^4.2.1",
     "openai": "^4.27.0",
     "pug": "^3.0.2",
     "resend": "^2.0.0",

backend/src/cron/invoiceCron.js

@@ -0,0 +1,36 @@
+const cron = require('node-cron');
+const Invoice = require('../models/appModels/Invoice');
+
+// 📚 Cron format: 'minute hour day month weekday'
+// '0 0 * * *' means → at 00:00 (midnight) every day
+cron.schedule('0 0 * * *', async () => {
+  console.log('⏰ Running daily invoice expiry check...');
+
+  const today = new Date();
+
+  try {
+    // 📚 updateMany = update ALL documents that match the filter
+    const expiredInvoices = await Invoice.updateMany(
+      {
+        // 📚 $lt = "less than" → find invoices where expiredDate < today
+        expiredDate: { $lt: today },
+        isOverdue: false, // only update ones not already marked
+        removed: false,   // skip deleted invoices
+      },
+      {
+        // 📚 $set = update these fields
+        $set: {
+          isOverdue: true,
+          status: 'overdue',
+        },
+      }
+    );
+
+    console.log(`✅ ${expiredInvoices.modifiedCount} invoices marked as overdue`);
+
+  } catch (error) {
+    console.error('❌ Cron job failed:', error.message);
+  }
+});
+
+console.log('✅ Invoice expiry cron job scheduled — runs daily at midnight!');

backend/src/server.js

@@ -31,6 +31,9 @@ for (const filePath of modelsFiles) {
   require(path.resolve(filePath));
 }
 
+// Start cron jobs
+require('./src/cron/invoiceCron');
+
 // Start our app!
 const app = require('./app');
 app.set('port', process.env.PORT || 8888);