feat: creates backend for the project

backend/src/middleware/auth.ts

@@ -0,0 +1,50 @@
+import { Request, Response, NextFunction } from 'express';
+import { pool } from '../db/pool';
+import { config } from '../config';
+
+declare global {
+  namespace Express {
+    interface Request {
+      sessionId?: string;
+    }
+  }
+}
+
+export async function requireAuth(
+  req: Request,
+  res: Response,
+  next: NextFunction,
+): Promise<void> {
+  const sid = req.cookies?.sid;
+  if (!sid) {
+    res.status(401).json({ error: 'UNAUTHORIZED', message: 'No session' });
+    return;
+  }
+
+  const { rows } = await pool.query(
+    'SELECT id, last_activity_at, is_active FROM sessions WHERE id = $1',
+    [sid],
+  );
+
+  if (rows.length === 0 || !rows[0].is_active) {
+    res.clearCookie('sid');
+    res.status(401).json({ error: 'UNAUTHORIZED', message: 'Invalid session' });
+    return;
+  }
+
+  const lastActivity = new Date(rows[0].last_activity_at).getTime();
+  if (Date.now() - lastActivity > config.sessionTimeoutMs) {
+    await pool.query('UPDATE sessions SET is_active = FALSE WHERE id = $1', [sid]);
+    res.clearCookie('sid');
+    res.status(401).json({ error: 'UNAUTHORIZED', message: 'Session expired' });
+    return;
+  }
+
+  await pool.query(
+    'UPDATE sessions SET last_activity_at = NOW() WHERE id = $1',
+    [sid],
+  );
+
+  req.sessionId = sid;
+  next();
+}