feat: Move language option to profile setting (#387)

backend/routes/users/updateLocale.js

@@ -0,0 +1,46 @@
+import express from 'express';
+import { DataTypes } from 'sequelize';
+import defineUser from '../../models/users.js';
+import authMiddleware from '../../middleware/auth.js';
+import { SUPPORTED_LOCALES } from '../../config/locale.js';
+const router = express.Router();
+
+export default function (sequelize) {
+  const { verifySignedIn } = authMiddleware(sequelize);
+  const User = defineUser(sequelize, DataTypes);
+
+  router.put('/locale', verifySignedIn, async (req, res) => {
+    try {
+      const userId = req.userId;
+
+      const user = await User.findByPk(userId);
+      if (!user) {
+        return res.status(404).send('User not found');
+      }
+
+      const { locale } = req.body;
+
+      const normalizedLocale = typeof locale === 'string' ? locale.trim() : '';
+      if (!normalizedLocale || normalizedLocale.length === 0) {
+        return res.status(400).send('Locale is required');
+      }
+
+      if (!SUPPORTED_LOCALES.includes(normalizedLocale)) {
+        return res.status(400).send('Invalid locale');
+      }
+
+      await user.update({ locale: normalizedLocale });
+
+      const updatedUser = await User.findByPk(userId, {
+        attributes: ['id', 'email', 'username', 'role', 'avatarPath', 'locale'],
+      });
+
+      res.json({ user: updatedUser });
+    } catch (error) {
+      console.error(error);
+      res.status(500).send('Internal Server Error');
+    }
+  });
+
+  return router;
+}