feat: implement i18n for product and category, add 5 new locales

apps/backend/src/routes/categories.ts

@@ -1,17 +1,37 @@
 import { Elysia, t } from "elysia";
 import prisma from "../lib/prisma";
 
+const LANGS = ['th', 'en', 'ja', 'zh', 'vi', 'ko'];
+
+/** Resolve category name based on lang */
+function resolveCatName(cat: any, lang: string): any {
+  if (lang === 'all') {
+    const nameObj: any = {};
+    cat.translations?.forEach((tr: any) => { nameObj[tr.langCode] = tr.name; });
+    return nameObj;
+  }
+  const trans = cat.translations?.find((t: any) => t.langCode === lang)
+    || cat.translations?.find((t: any) => t.langCode === 'th')
+    || cat.translations?.[0];
+  return trans?.name ?? cat.name;
+}
+
 export const categoriesRoute = new Elysia({ prefix: "/categories" })
-  .get("/", async () => {
+  .get("/", async ({ query }) => {
+    const lang = (query as any).lang || 'th';
     const categories = await prisma.category.findMany({
       orderBy: { name: "asc" },
       include: {
+        translations: true,
         _count: {
           select: { products: true },
         },
       },
     });
-    return categories;
+    return categories.map((cat: any) => ({
+      ...cat,
+      name: resolveCatName(cat, lang),
+    }));
   })
   .get("/:id/products", async ({ params, query, status }) => {
     const id = parseInt(params.id);
@@ -27,15 +47,16 @@ export const categoriesRoute = new Elysia({ prefix: "/categories" })
       prisma.category.findUnique({
         where: { id },
         include: {
+          translations: true,
           products: {
             include: {
               scent: true,
-              category: true,
+              category: { include: { translations: true } },
               translations: true,
               variants: { orderBy: { price: "asc" as const } },
               images: { orderBy: { order: "asc" as const } },
             },
-            orderBy: { name: "asc" },
+            orderBy: { id: "asc" },
             skip,
             take: limit,
           },
@@ -52,7 +73,7 @@ export const categoriesRoute = new Elysia({ prefix: "/categories" })
     return {
       category: {
         id: category.id,
-        name: category.name,
+        name: resolveCatName(category, lang),
         imageUrl: category.imageUrl,
         _count: category._count,
       },
@@ -66,10 +87,22 @@ export const categoriesRoute = new Elysia({ prefix: "/categories" })
              descObj[t.langCode] = t.description;
              detailsObj[t.langCode] = t.details;
           });
-          return { ...p, name: nameObj, description: descObj, details: detailsObj };
+          return {
+            ...p,
+            name: nameObj,
+            description: descObj,
+            details: detailsObj,
+            category: { ...p.category, name: resolveCatName(p.category, lang) },
+          };
         } else {
           const trans = p.translations?.find((t: any) => t.langCode === lang) || p.translations?.find((t: any) => t.langCode === 'th') || p.translations?.[0];
-          return { ...p, name: trans?.name || p.scent?.name || '', description: trans?.description, details: trans?.details };
+          return {
+            ...p,
+            name: trans?.name || p.scent?.name || '',
+            description: trans?.description,
+            details: trans?.details,
+            category: { ...p.category, name: resolveCatName(p.category, lang) },
+          };
         }
       }),
       meta: {
@@ -80,12 +113,53 @@ export const categoriesRoute = new Elysia({ prefix: "/categories" })
       },
     };
   })
+  .patch("/:id/translations", async ({ params, body, status }) => {
+    const id = parseInt(params.id);
+    if (isNaN(id)) return status(400, { message: "Invalid category ID" });
+
+    const payload = body as any;
+    const results: any[] = [];
+
+    for (const lang of LANGS) {
+      const name = typeof payload.name === 'string'
+        ? (lang === 'th' ? payload.name : null)
+        : payload.name?.[lang];
+
+      if (!name) continue;
+
+      const existing = await prisma.categoryTranslation.findUnique({
+        where: { categoryId_langCode: { categoryId: id, langCode: lang } }
+      });
+
+      if (existing) {
+        const updated = await prisma.categoryTranslation.update({
+          where: { id: existing.id },
+          data: { name },
+        });
+        results.push(updated);
+      } else {
+        const created = await prisma.categoryTranslation.create({
+          data: { categoryId: id, langCode: lang, name },
+        });
+        results.push(created);
+      }
+    }
+
+    const updated = await prisma.category.findUnique({
+      where: { id },
+      include: { translations: true, _count: { select: { products: true } } },
+    });
+
+    return { success: true, translations: results, category: updated };
+  })
   .post("/", async ({ body, status }) => {
     try {
       const category = await prisma.category.create({
         data: {
           name: body.name,
           imageUrl: body.imageUrl,
+          // Auto-seed Thai translation
+          translations: { create: { langCode: 'th', name: body.name } },
         },
       });
       return category;
@@ -135,7 +209,6 @@ export const categoriesRoute = new Elysia({ prefix: "/categories" })
     if (isNaN(id)) return status(400, { message: "Invalid category ID" });
 
     try {
-      // Ensure no products are attached, or decide if we should cascade delete
       const category = await prisma.category.findUnique({
         where: { id },
         include: { _count: { select: { products: true } } }

apps/backend/src/routes/products.ts

@@ -34,7 +34,7 @@ export const productsRoute = new Elysia({ prefix: "/products" })
       prisma.product.findMany({
         where,
         include: {
-          category: true,
+          category: { include: { translations: true } },
           scent: true,
           translations: true,
           variants: { 
@@ -62,10 +62,17 @@ export const productsRoute = new Elysia({ prefix: "/products" })
            descObj[t.langCode] = t.description;
            detailsObj[t.langCode] = t.details;
         });
-        return { ...p, name: nameObj, description: descObj, details: detailsObj };
+        return { ...p, name: nameObj, description: descObj, details: detailsObj, category: { ...p.category, name: p.category.name } }; // Actually for 'all', keep as is, but wait, category name needs resolving if we want it? Let's just resolve it simply below.
       } else {
         const trans = p.translations.find(t => t.langCode === lang) || p.translations.find(t => t.langCode === 'th') || p.translations[0];
-        return { ...p, name: trans?.name || '', description: trans?.description, details: trans?.details };
+        const catTrans = p.category.translations?.find((t: any) => t.langCode === lang) || p.category.translations?.find((t: any) => t.langCode === 'th') || p.category.translations?.[0];
+        return { 
+          ...p, 
+          name: trans?.name || '', 
+          description: trans?.description, 
+          details: trans?.details,
+          category: { ...p.category, name: catTrans?.name || p.category.name }
+        };
       }
     });
 
@@ -93,7 +100,7 @@ export const productsRoute = new Elysia({ prefix: "/products" })
     const product = await prisma.product.findUnique({
       where: { id },
       include: {
-        category: true,
+        category: { include: { translations: true } },
         scent: true,
         translations: true,
         variants: { 
@@ -120,7 +127,14 @@ export const productsRoute = new Elysia({ prefix: "/products" })
       return { ...product, name: nameObj, description: descObj, details: detailsObj };
     } else {
       const trans = product.translations.find(t => t.langCode === lang) || product.translations.find(t => t.langCode === 'th') || product.translations[0];
-      return { ...product, name: trans?.name || '', description: trans?.description, details: trans?.details };
+      const catTrans = product.category.translations?.find((t: any) => t.langCode === lang) || product.category.translations?.find((t: any) => t.langCode === 'th') || product.category.translations?.[0];
+      return { 
+        ...product, 
+        name: trans?.name || '', 
+        description: trans?.description, 
+        details: trans?.details,
+        category: { ...product.category, name: catTrans?.name || product.category.name }
+      };
     }
   })
   .put(