feat(cms): implement multi-language support across frontend and admin UI

apps/backend/src/routes/settings.ts

@@ -53,4 +53,60 @@ export const settingsRoute = new Elysia({ prefix: "/settings" })
       newsletterPlaceholder: t.Optional(t.String()),
       newsletterButtonText: t.Optional(t.String())
     })
+  })
+  .patch("/translations", async ({ body, set }) => {
+    try {
+      let settings = await prisma.storeSettings.findFirst();
+      if (!settings) {
+        settings = await prisma.storeSettings.create({ data: {} });
+      }
+
+      const payload = body as any;
+      const results: any[] = [];
+      const LANGS = ['th', 'en', 'ja', 'zh', 'vi', 'ko'];
+
+      for (const lang of LANGS) {
+        const footerDescription = typeof payload.footerDescription === 'string' ? (lang === 'th' ? payload.footerDescription : null) : payload.footerDescription?.[lang];
+        const newsletterTitle = typeof payload.newsletterTitle === 'string' ? (lang === 'th' ? payload.newsletterTitle : null) : payload.newsletterTitle?.[lang];
+        const newsletterDescription = typeof payload.newsletterDescription === 'string' ? (lang === 'th' ? payload.newsletterDescription : null) : payload.newsletterDescription?.[lang];
+        const newsletterPlaceholder = typeof payload.newsletterPlaceholder === 'string' ? (lang === 'th' ? payload.newsletterPlaceholder : null) : payload.newsletterPlaceholder?.[lang];
+        const newsletterButtonText = typeof payload.newsletterButtonText === 'string' ? (lang === 'th' ? payload.newsletterButtonText : null) : payload.newsletterButtonText?.[lang];
+
+        if (!footerDescription && !newsletterTitle && !newsletterDescription && !newsletterPlaceholder && !newsletterButtonText) continue;
+
+        const existing = await prisma.storeSettingsTranslation.findUnique({
+          where: { storeSettingsId_langCode: { storeSettingsId: settings.id, langCode: lang } }
+        });
+
+        const updateData: any = {};
+        if (footerDescription) updateData.footerDescription = footerDescription;
+        if (newsletterTitle) updateData.newsletterTitle = newsletterTitle;
+        if (newsletterDescription) updateData.newsletterDescription = newsletterDescription;
+        if (newsletterPlaceholder) updateData.newsletterPlaceholder = newsletterPlaceholder;
+        if (newsletterButtonText) updateData.newsletterButtonText = newsletterButtonText;
+
+        if (existing) {
+          const updated = await prisma.storeSettingsTranslation.update({
+            where: { id: existing.id },
+            data: updateData
+          });
+          results.push(updated);
+        } else {
+          const created = await prisma.storeSettingsTranslation.create({
+            data: { storeSettingsId: settings.id, langCode: lang, ...updateData }
+          });
+          results.push(created);
+        }
+      }
+
+      const updatedSettings = await prisma.storeSettings.findFirst({
+        include: { translations: true }
+      });
+
+      return { success: true, translations: results, settings: updatedSettings };
+    } catch (err) {
+      console.error("[Settings] Translation Error:", err);
+      set.status = 500;
+      return { error: "Failed to update settings translation" };
+    }
   });