cd backend
npm install prisma @prisma/client
npx prisma init

// prisma/schema.prisma
generator client {
  provider = "prisma-client-js"
}

datasource db {
  provider = "postgresql"
  url      = env("DATABASE_URL")
}

model Product {
  id               Int                    @id @default(autoincrement())
  name             String
  shortDescription String                 @map("short_description")
  description      String
  price            Decimal                @db.Decimal(10, 2)
  salePrice        Decimal?               @map("sale_price") @db.Decimal(10, 2)
  imageUrl         String                 @map("image_url")
  inventory        Int                    @default(0)
  categories       Json
  highlights       Json?
  usage            String?
  isNew            Boolean                @default(false) @map("is_new")
  isFeatured       Boolean                @default(false) @map("is_featured")
  salesCount       Int                    @default(0) @map("sales_count")
  createdAt        DateTime               @default(now()) @map("created_at")
  updatedAt        DateTime               @updatedAt @map("updated_at")
  translations     ProductTranslation[]
  orderItems       OrderItem[]
  variants         ProductVariant[]

  @@map("products")
}

model ProductTranslation {
  id              Int      @id @default(autoincrement())
  productId       Int      @map("product_id")
  languageCode    String   @map("language_code") @db.VarChar(10)
  name            String   @db.VarChar(255)
  shortDescription String  @map("short_description")
  description     String
  highlights      Json?
  usage           String?
  slug            String?  @db.VarChar(255)
  createdAt       DateTime @default(now()) @map("created_at")
  updatedAt       DateTime @updatedAt @map("updated_at")
  product         Product  @relation(fields: [productId], references: [id], onDelete: Cascade)
  language        Language @relation(fields: [languageCode], references: [code], onDelete: Cascade)

  @@unique([productId, languageCode])
  @@map("product_translations")
}

// backend/src/db/prisma.ts
import { PrismaClient } from '@prisma/client';

const prisma = new PrismaClient({
  log: process.env.NODE_ENV === 'development' ? ['query', 'warn', 'error'] : ['error'],
});

export { prisma };

const product = await prisma.product.findUnique({
  where: { id: productId },
  include: {
    translations: {
      where: { languageCode: lang },
    },
  },
});

// Apply translation or fallback to base
const name = product.translations[0]?.name ?? product.name;

await prisma.$transaction(async (tx) => {
  const order = await tx.order.create({ data: orderData });
  
  for (const item of items) {
    await tx.orderItem.create({
      data: { orderId: order.id, ...item },
    });
    await tx.product.update({
      where: { id: item.productId },
      data: { inventory: { decrement: item.quantity } },
    });
  }
  
  return order;
});