better item primary key and cart updates, balance updating WIP

src/app/api/buy/route.ts

@@ -0,0 +1,97 @@
+import { NextResponse } from "next/server";
+import { auth } from "~/server/auth";
+import { db } from "~/server/db";
+
+type Order = {
+  cart: { id: string; quantity: number }[];
+  address: string;
+};
+
+export async function POST(request: Request) {
+  const { address, cart } = (await request.json()) as Order;
+  const session = await auth();
+
+  if (!session) {
+    return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
+  }
+
+  const userId = session.user.id;
+
+  try {
+    if (!cart || cart.length === 0) {
+      return NextResponse.json({ error: "Cart is empty" }, { status: 400 });
+    }
+
+    // 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) } },
+      include: {
+        sellable: {
+          include: {
+            item: true, // include item to get shopId
+          },
+        },
+      },
+    });
+
+    if (cartItemsWithShop.length === 0) {
+      return NextResponse.json(
+        { error: "No valid items in cart" },
+        { status: 400 },
+      );
+    }
+
+    // Group items by shopId
+    const itemsByShop: Record<number, { id: string; quantity: number }[]> = {};
+
+    for (const ci of cartItemsWithShop) {
+      const shopId = ci.sellable.item.shopId; // get shopId from item
+      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,
+      });
+    }
+
+    console.log(itemsByShop);
+
+    // Send requests per shop
+    for (const [shopId, items] of Object.entries(itemsByShop)) {
+      const body = JSON.stringify({
+        shopId: Number(shopId),
+        address,
+        items,
+      });
+
+      console.log("Sending to shop:", shopId, body);
+
+      const response = await fetch(process.env.ITEM_SEND_API!, {
+        method: "POST",
+        headers: { "Content-Type": "application/json" },
+        body,
+      });
+
+      if (!response.ok) {
+        const errorText = await response.text();
+        return NextResponse.json(
+          { error: `Failed to send items to shop ${shopId}: ${errorText}` },
+          { status: response.status },
+        );
+      }
+
+      // Delete successfully sent items from cart
+      const itemIds = items.map((i) => i.id);
+      await db.cartItem.deleteMany({
+        where: {
+          cartId: userId,
+          sellable: { item_name: { in: itemIds } },
+        },
+      });
+    }
+
+    return NextResponse.json({ success: true });
+  } catch (error) {
+    console.error(error);
+    return NextResponse.json({ error: "Server error" }, { status: 500 });
+  }
+}