feat(cart): update CartItem model to use composite key and adjust related logic

fix(cart): ensure cart item updates and deletions are based on cartId and itemId

feat(buy): implement balance checks and updates during purchase process

fix(sellable): ensure cart items are deleted when a sellable is removed

feat(user): add conflict checks for shop creation to prevent ID collisions

generated/prisma/index.d.ts

@@ -12274,15 +12274,16 @@ export namespace Prisma {
   }
 
   export type CartItemWhereUniqueInput = Prisma.AtLeast<{
-    itemId?: string
+    cartId_itemId?: CartItemCartIdItemIdCompoundUniqueInput
     AND?: CartItemWhereInput | CartItemWhereInput[]
     OR?: CartItemWhereInput[]
     NOT?: CartItemWhereInput | CartItemWhereInput[]
+    itemId?: StringFilter<"CartItem"> | string
     quantity?: IntFilter<"CartItem"> | number
     cartId?: StringFilter<"CartItem"> | string
     cart?: XOR<CartScalarRelationFilter, CartWhereInput>
     sellable?: XOR<SellableScalarRelationFilter, SellableWhereInput>
-  }, "itemId">
+  }, "cartId_itemId">
 
   export type CartItemOrderByWithAggregationInput = {
     itemId?: SortOrder
@@ -13532,6 +13533,11 @@ export namespace Prisma {
     search: string
   }
 
+  export type CartItemCartIdItemIdCompoundUniqueInput = {
+    cartId: string
+    itemId: string
+  }
+
   export type CartItemCountOrderByAggregateInput = {
     itemId?: SortOrder
     quantity?: SortOrder

generated/prisma/package.json

@@ -1,5 +1,5 @@
 {
-  "name": "prisma-client-60cecad7f5344b2ab216d0c215477a4a9f0fb3ec9e5201c830e0c4ac3caafb77",
+  "name": "prisma-client-7f3601640bc9191b9770c2fe70db074b0364e5d01ec2def94d81cee0c9a18abc",
   "main": "index.js",
   "types": "index.d.ts",
   "browser": "default.js",

generated/prisma/schema.prisma

@@ -117,12 +117,14 @@ model Cart {
 }
 
 model CartItem {
-  itemId   String @id
+  itemId   String
   quantity Int
   cartId   String
 
   cart     Cart     @relation(fields: [cartId], references: [userId], onDelete: Cascade, onUpdate: Cascade)
   sellable Sellable @relation(fields: [itemId], references: [id], onDelete: Cascade, onUpdate: Cascade)
+
+  @@id([cartId, itemId])
 }
 
 //////////////////////

generated/prisma/wasm.js

@@ -263,7 +263,7 @@ const config = {
       "value": "prisma-client-js"
     },
     "output": {
-      "value": "/var/home/zaremate/Documents/cc-create-shop/generated/prisma",
+      "value": "/var/mnt/f5a90b51-c040-4601-a32c-9629866f15a2/Documents/cc-create-shop/generated/prisma",
       "fromEnvVar": null
     },
     "config": {
@@ -277,7 +277,7 @@ const config = {
       }
     ],
     "previewFeatures": [],
-    "sourceFilePath": "/var/home/zaremate/Documents/cc-create-shop/prisma/schema.prisma",
+    "sourceFilePath": "/var/mnt/f5a90b51-c040-4601-a32c-9629866f15a2/Documents/cc-create-shop/prisma/schema.prisma",
     "isCustomOutput": true
   },
   "relativeEnvPaths": {
@@ -299,8 +299,8 @@ const config = {
       }
     }
   },
-  "inlineSchema": "// This is your Prisma schema file,\n// learn more about it in the docs: https://pris.ly/d/prisma-schema\n\ngenerator client {\n  provider = \"prisma-client-js\"\n  output   = \"../generated/prisma\"\n}\n\ndatasource db {\n  provider = \"mysql\"\n  // NOTE: When using mysql or sqlserver, uncomment the @db.Text annotations in model Account below\n  // Further reading:\n  // https://next-auth.js.org/adapters/prisma#create-the-prisma-schema\n  // https://www.prisma.io/docs/reference/api-reference/prisma-schema-reference#string\n  url      = env(\"DATABASE_URL\")\n}\n\n// Necessary for Next auth\nmodel Account {\n  id                       String  @id @default(cuid())\n  userId                   String\n  type                     String\n  provider                 String\n  providerAccountId        String\n  refresh_token            String? @db.Text\n  access_token             String? // @db.Text\n  expires_at               Int?\n  token_type               String?\n  scope                    String?\n  id_token                 String? // @db.Text\n  session_state            String?\n  user                     User    @relation(fields: [userId], references: [id], onDelete: Cascade)\n  refresh_token_expires_in Int?\n\n  @@unique([provider, providerAccountId])\n}\n\nmodel Session {\n  id           String   @id @default(cuid())\n  sessionToken String   @unique\n  userId       String\n  expires      DateTime\n  user         User     @relation(fields: [userId], references: [id], onDelete: Cascade)\n}\n\nmodel User {\n  id            String    @id @default(cuid())\n  name          String?\n  email         String?   @unique\n  emailVerified DateTime?\n  image         String?\n  balance       Float     @default(1000)\n\n  accounts Account[]\n  sessions Session[]\n  shops    Shop[]\n  carts    Cart[]\n  adresses Adress[]\n}\n\nmodel VerificationToken {\n  identifier String\n  token      String   @unique\n  expires    DateTime\n\n  @@unique([identifier, token])\n}\n\n//////////////////////\n// SHOP\n//////////////////////\n\nmodel Shop {\n  id     Int    @id\n  userId String\n  label  String\n\n  user      User       @relation(fields: [userId], references: [id], onDelete: Cascade, onUpdate: Cascade)\n  items     Item[]\n  sellables Sellable[]\n}\n\nmodel Item {\n  item_name String\n  shopId    Int\n  stock     Int\n\n  shop      Shop       @relation(fields: [shopId], references: [id], onDelete: Cascade, onUpdate: Cascade)\n  sellables Sellable[]\n\n  @@id([item_name, shopId])\n}\n\nmodel Sellable {\n  id        String  @id @default(cuid())\n  item_name String\n  shopId    Int\n  amount    Int\n  price     Float\n  enabled   Boolean @default(true)\n\n  shop Shop @relation(fields: [shopId], references: [id], onDelete: Cascade)\n  item Item @relation(fields: [item_name, shopId], references: [item_name, shopId], onDelete: Cascade)\n\n  cartItems CartItem[]\n}\n\n//////////////////////\n// CART\n//////////////////////\n\nmodel Cart {\n  userId String @id\n\n  user      User       @relation(fields: [userId], references: [id], onDelete: Cascade, onUpdate: Cascade)\n  cartItems CartItem[]\n}\n\nmodel CartItem {\n  itemId   String @id\n  quantity Int\n  cartId   String\n\n  cart     Cart     @relation(fields: [cartId], references: [userId], onDelete: Cascade, onUpdate: Cascade)\n  sellable Sellable @relation(fields: [itemId], references: [id], onDelete: Cascade, onUpdate: Cascade)\n}\n\n//////////////////////\n// ADDRESS\n//////////////////////\n\nmodel Adress {\n  id     String @id @default(cuid())\n  userId String\n  adress String\n\n  user User @relation(fields: [userId], references: [id], onDelete: Cascade, onUpdate: Cascade)\n}\n",
+  "inlineSchema": "// This is your Prisma schema file,\n// learn more about it in the docs: https://pris.ly/d/prisma-schema\n\ngenerator client {\n  provider = \"prisma-client-js\"\n  output   = \"../generated/prisma\"\n}\n\ndatasource db {\n  provider = \"mysql\"\n  // NOTE: When using mysql or sqlserver, uncomment the @db.Text annotations in model Account below\n  // Further reading:\n  // https://next-auth.js.org/adapters/prisma#create-the-prisma-schema\n  // https://www.prisma.io/docs/reference/api-reference/prisma-schema-reference#string\n  url      = env(\"DATABASE_URL\")\n}\n\n// Necessary for Next auth\nmodel Account {\n  id                       String  @id @default(cuid())\n  userId                   String\n  type                     String\n  provider                 String\n  providerAccountId        String\n  refresh_token            String? @db.Text\n  access_token             String? // @db.Text\n  expires_at               Int?\n  token_type               String?\n  scope                    String?\n  id_token                 String? // @db.Text\n  session_state            String?\n  user                     User    @relation(fields: [userId], references: [id], onDelete: Cascade)\n  refresh_token_expires_in Int?\n\n  @@unique([provider, providerAccountId])\n}\n\nmodel Session {\n  id           String   @id @default(cuid())\n  sessionToken String   @unique\n  userId       String\n  expires      DateTime\n  user         User     @relation(fields: [userId], references: [id], onDelete: Cascade)\n}\n\nmodel User {\n  id            String    @id @default(cuid())\n  name          String?\n  email         String?   @unique\n  emailVerified DateTime?\n  image         String?\n  balance       Float     @default(1000)\n\n  accounts Account[]\n  sessions Session[]\n  shops    Shop[]\n  carts    Cart[]\n  adresses Adress[]\n}\n\nmodel VerificationToken {\n  identifier String\n  token      String   @unique\n  expires    DateTime\n\n  @@unique([identifier, token])\n}\n\n//////////////////////\n// SHOP\n//////////////////////\n\nmodel Shop {\n  id     Int    @id\n  userId String\n  label  String\n\n  user      User       @relation(fields: [userId], references: [id], onDelete: Cascade, onUpdate: Cascade)\n  items     Item[]\n  sellables Sellable[]\n}\n\nmodel Item {\n  item_name String\n  shopId    Int\n  stock     Int\n\n  shop      Shop       @relation(fields: [shopId], references: [id], onDelete: Cascade, onUpdate: Cascade)\n  sellables Sellable[]\n\n  @@id([item_name, shopId])\n}\n\nmodel Sellable {\n  id        String  @id @default(cuid())\n  item_name String\n  shopId    Int\n  amount    Int\n  price     Float\n  enabled   Boolean @default(true)\n\n  shop Shop @relation(fields: [shopId], references: [id], onDelete: Cascade)\n  item Item @relation(fields: [item_name, shopId], references: [item_name, shopId], onDelete: Cascade)\n\n  cartItems CartItem[]\n}\n\n//////////////////////\n// CART\n//////////////////////\n\nmodel Cart {\n  userId String @id\n\n  user      User       @relation(fields: [userId], references: [id], onDelete: Cascade, onUpdate: Cascade)\n  cartItems CartItem[]\n}\n\nmodel CartItem {\n  itemId   String\n  quantity Int\n  cartId   String\n\n  cart     Cart     @relation(fields: [cartId], references: [userId], onDelete: Cascade, onUpdate: Cascade)\n  sellable Sellable @relation(fields: [itemId], references: [id], onDelete: Cascade, onUpdate: Cascade)\n\n  @@id([cartId, itemId])\n}\n\n//////////////////////\n// ADDRESS\n//////////////////////\n\nmodel Adress {\n  id     String @id @default(cuid())\n  userId String\n  adress String\n\n  user User @relation(fields: [userId], references: [id], onDelete: Cascade, onUpdate: Cascade)\n}\n",
-  "inlineSchemaHash": "6067e34ba0a13fe49002e5198964784b3870ee91700e9649c3b9ffe64ee9c688",
+  "inlineSchemaHash": "f1f25ffbae59b74d980dd4ecdf5d9929994691bf2809d9a3468ab2985796fd99",
   "copyEngine": true
 }
 config.dirname = '/'

prisma/schema.prisma

@@ -117,12 +117,14 @@ model Cart {
 }
 
 model CartItem {
-  itemId   String @id
+  itemId   String
   quantity Int
   cartId   String
 
   cart     Cart     @relation(fields: [cartId], references: [userId], onDelete: Cascade, onUpdate: Cascade)
   sellable Sellable @relation(fields: [itemId], references: [id], onDelete: Cascade, onUpdate: Cascade)
+
+  @@id([cartId, itemId])
 }
 
 //////////////////////

src/app/api/buy/route.ts

@@ -24,7 +24,10 @@ export async function POST(request: Request) {
 
     // Fetch all cart items with related sellable and item to get shopId
     const cartItemsWithShop = await db.cartItem.findMany({
-      where: { itemId: { in: cart.map((c) => c.id) } },
+      where: {
+        cartId: userId,
+        itemId: { in: cart.map((c) => c.id) },
+      },
       include: {
         sellable: {
           include: {
@@ -49,10 +52,27 @@ export async function POST(request: Request) {
       itemsByShop[shopId] ??= []; // initialize if undefined or null
       itemsByShop[shopId].push({
         id: ci.sellable.item.item_name, // API expects item_name as id
-        quantity: ci.quantity,
+        quantity: ci.quantity * ci.sellable.amount, // total quantity based on cart item quantity and sellable amount
       });
     }
 
+    // Check if user has enough balance for all items
+    const totalCost = cartItemsWithShop.reduce((sum, ci) => {
+      return sum + ci.quantity * ci.sellable.price;
+    }, 0);
+
+    const user = await db.user.findUnique({
+      where: { id: userId },
+      select: { balance: true },
+    });
+
+    if (!user || user.balance < totalCost) {
+      return NextResponse.json(
+        { error: "Insufficient balance" },
+        { status: 400 },
+      );
+    }
+
     console.log(itemsByShop);
 
     // Send requests per shop
@@ -79,6 +99,27 @@ export async function POST(request: Request) {
         );
       }
 
+      // Deduct the total cost from the user's balance
+      await db.user.update({
+        where: { id: userId },
+        data: { balance: { decrement: totalCost } },
+      });
+
+      // Add balance to shop owner
+      console.log("Updating shop owner balance for shop:", shopId);
+      const shop = await db.shop.findUnique({
+        where: { id: Number(shopId) },
+        select: { userId: true },
+      });
+      console.log("Shop owner userId:", shop?.userId);
+      console.log("Total cost to add to shop owner:", totalCost);
+      if (shop) {
+        await db.user.update({
+          where: { id: shop.userId },
+          data: { balance: { increment: totalCost } },
+        });
+      }
+
       // Delete successfully sent items from cart
       const itemIds = items.map((i) => i.id);
       await db.cartItem.deleteMany({

src/app/api/cart/route.ts

@@ -39,29 +39,46 @@ export async function PATCH(request: Request) {
     });
 
     // Check if the item already exists in the cart
-    const existingCartItem = await db.cartItem.findUnique({
+    const existingCartItem = await db.cartItem.findFirst({
-      where: { itemId },
+      where: {
+        cartId: userId,
+        itemId,
+      },
     });
 
     if (existingCartItem) {
-      if (quantity <= 0 && quantity * -1 >= existingCartItem.quantity) {
+      const nextQuantity = existingCartItem.quantity + quantity;
-        await db.cartItem.delete({
+
-          where: { itemId },
+      if (nextQuantity <= 0) {
+        await db.cartItem.deleteMany({
+          where: {
+            cartId: userId,
+            itemId,
+          },
         });
       } else {
-        // Update quantity
+        await db.cartItem.updateMany({
-        await db.cartItem.update({
+          where: {
-          where: { itemId },
+            cartId: userId,
-          data: { quantity: existingCartItem.quantity + quantity },
+            itemId,
+          },
+          data: { quantity: nextQuantity },
         });
       }
     } else {
+      if (quantity < 0) {
+        return NextResponse.json(
+          { error: "Cannot remove an item that is not in the cart" },
+          { status: 400 },
+        );
+      }
+
       // Add new item
       await db.cartItem.create({
         data: {
           itemId,
           quantity,
-          cartId: userId,
+          cartId: cart.userId,
         },
       });
     }

src/app/api/sellable/route.ts

@@ -97,6 +97,10 @@ export async function DELETE(request: Request) {
     return NextResponse.json({ error: "Item not found" }, { status: 404 });
   }
 
+  await db.cartItem.deleteMany({
+    where: { itemId: item.id },
+  });
+
   await db.sellable.delete({
     where: {
       id: item.id,

src/app/api/user/route.ts

@@ -141,6 +141,22 @@ export async function POST(request: Request) {
   const shopsToCreate = body.shops.filter((s) => !currentShopIds.has(s.id));
 
   if (shopsToCreate.length > 0) {
+    const conflictingShops = await db.shop.findMany({
+      where: {
+        id: { in: shopsToCreate.map((s) => s.id) },
+        NOT: { userId: session.user.id },
+      },
+      select: { id: true },
+    });
+
+    if (conflictingShops.length > 0) {
+      const conflictIds = conflictingShops.map((s) => s.id).join(", ");
+      return NextResponse.json(
+        { error: `Shop ID(s) already claimed by another user: ${conflictIds}` },
+        { status: 409 },
+      );
+    }
+
     await db.shop.createMany({
       data: shopsToCreate.map((s) => ({
         id: s.id,