chore: Add MonitorController for printer status monitoring

src/controllers/MonitorController.ts

@@ -0,0 +1,30 @@
+import { Router, Request, Response } from 'express'
+import { prisma } from '../prisma.js'
+
+const router = Router()
+
+class MonitorController {
+  static async status(req: Request, res: Response) {
+    // If last status has a toner level below 20%, send an alert
+    const { printerId } = req.params
+
+    const status = await prisma.printerStatus.findFirst({
+      where: {
+        printer: {
+          serialNumber: printerId
+        }
+      },
+      orderBy: { timestamp: 'desc' }
+    })
+
+    if (status?.tonerBlackLevel && status.tonerBlackLevel < 25) {
+      res.send('low toner')
+    } else {
+      res.send('ok')
+    }
+  }
+}
+
+router.get('/:printerId', MonitorController.status)
+
+export default router

src/server.ts

@@ -10,6 +10,7 @@ import PrinterRouter from './controllers/PrinterController.js'
 import PrinterStatusRouter from './controllers/PrinterStatusController.js'
 import PrinterDiscoveryRouter from './controllers/PrinterDiscoveryController.js'
 import EventsRouter from './controllers/EventsController.js'
+import MonitorController from './controllers/MonitorController.js'
 
 export const app = express()
 
@@ -29,6 +30,7 @@ app.use('/api/printer', PrinterRouter)
 app.use('/api/status', PrinterStatusRouter)
 app.use('/api/discovery', PrinterDiscoveryRouter)
 app.use('/api/events', EventsRouter)
+app.use('/api/monitor', MonitorController)
 
 app.use('/', express.static('public'))