fix(webhook): handle Saleor legacy webhook payload format with snake_case fields

Saleor sends webhook payloads as arrays with snake_case fields:
- user_email instead of userEmail
- billing_address instead of billingAddress
- total_gross_amount instead of total.gross.amount
- etc.

Added convertPayloadToOrder() function to transform snake_case payload
to camelCase format expected by our email templates.

src/app/api/webhooks/saleor/route.ts

@@ -16,12 +16,49 @@ interface SaleorWebhookHeaders {
   "saleor-api-url": string;
 }
 
+// Saleor sends snake_case in webhook payloads
+interface SaleorLineItemPayload {
+  id: string;
+  product_name: string;
+  variant_name?: string;
+  quantity: number;
+  total_price_gross_amount: string;
+  currency: string;
+}
+
+interface SaleorAddressPayload {
+  first_name?: string;
+  last_name?: string;
+  street_address_1?: string;
+  street_address_2?: string;
+  city?: string;
+  postal_code?: string;
+  country?: string;
+  phone?: string;
+}
+
+interface SaleorOrderPayload {
+  id: string;
+  number: number;
+  user_email: string;
+  first_name?: string;
+  last_name?: string;
+  billing_address?: SaleorAddressPayload;
+  shipping_address?: SaleorAddressPayload;
+  lines: SaleorLineItemPayload[];
+  total_gross_amount: string;
+  shipping_price_gross_amount?: string;
+  currency: string;
+  language_code?: string;
+  metadata?: Record<string, string>;
+}
+
+// Internal camelCase interfaces for our code
 interface SaleorLineItem {
   id: string;
   productName: string;
   variantName?: string;
   quantity: number;
-  quantityUnit?: string;
   totalPrice: {
     gross: {
       amount: number;
@@ -84,6 +121,66 @@ const LANGUAGE_CODE_MAP: Record<string, string> = {
   FR: "fr",
 };
 
+// Convert Saleor snake_case payload to camelCase
+function convertPayloadToOrder(payload: SaleorOrderPayload): SaleorOrder {
+  return {
+    id: payload.id,
+    number: String(payload.number),
+    userEmail: payload.user_email,
+    user: payload.first_name || payload.last_name ? {
+      firstName: payload.first_name,
+      lastName: payload.last_name,
+      email: payload.user_email,
+    } : undefined,
+    billingAddress: payload.billing_address ? {
+      firstName: payload.billing_address.first_name,
+      lastName: payload.billing_address.last_name,
+      streetAddress1: payload.billing_address.street_address_1,
+      streetAddress2: payload.billing_address.street_address_2,
+      city: payload.billing_address.city,
+      postalCode: payload.billing_address.postal_code,
+      country: payload.billing_address.country,
+      phone: payload.billing_address.phone,
+    } : undefined,
+    shippingAddress: payload.shipping_address ? {
+      firstName: payload.shipping_address.first_name,
+      lastName: payload.shipping_address.last_name,
+      streetAddress1: payload.shipping_address.street_address_1,
+      streetAddress2: payload.shipping_address.street_address_2,
+      city: payload.shipping_address.city,
+      postalCode: payload.shipping_address.postal_code,
+      country: payload.shipping_address.country,
+      phone: payload.shipping_address.phone,
+    } : undefined,
+    lines: payload.lines.map((line) => ({
+      id: line.id,
+      productName: line.product_name,
+      variantName: line.variant_name,
+      quantity: line.quantity,
+      totalPrice: {
+        gross: {
+          amount: parseInt(line.total_price_gross_amount),
+          currency: line.currency,
+        },
+      },
+    })),
+    total: {
+      gross: {
+        amount: parseInt(payload.total_gross_amount),
+        currency: payload.currency,
+      },
+    },
+    shippingPrice: payload.shipping_price_gross_amount ? {
+      gross: {
+        amount: parseInt(payload.shipping_price_gross_amount),
+        currency: payload.currency,
+      },
+    } : undefined,
+    languageCode: payload.language_code?.toUpperCase(),
+    metadata: payload.metadata ? Object.entries(payload.metadata).map(([key, value]) => ({ key, value })) : undefined,
+  };
+}
+
 function getCustomerLanguage(order: SaleorOrder): string {
   if (order.languageCode && LANGUAGE_CODE_MAP[order.languageCode]) {
     return LANGUAGE_CODE_MAP[order.languageCode];
@@ -402,23 +499,24 @@ export async function POST(request: NextRequest) {
     console.log("Headers:", { event, domain, apiUrl, hasSignature: !!signature });
     console.log("Payload:", JSON.stringify(body).substring(0, 500));
     
-    // Handle Saleor subscription payload format (array of events)
-    let order = null;
-    if (Array.isArray(body)) {
-      // Find the order in the array
-      const orderEvent = body.find((item: any) => item.order);
-      if (orderEvent) {
-        order = orderEvent.order;
-      }
-    } else if (body.order) {
-      order = body.order;
+    // Handle Saleor legacy webhook payload format (array with snake_case fields)
+    let orderPayload: SaleorOrderPayload | null = null;
+    if (Array.isArray(body) && body.length > 0) {
+      // Legacy format: array with order objects directly
+      orderPayload = body[0] as SaleorOrderPayload;
+    } else if (body.data && Array.isArray(body.data)) {
+      // Subscription format: { data: [...] }
+      orderPayload = body.data[0] as SaleorOrderPayload;
     }
     
-    if (order) {
-      console.log("Order ID:", order.id);
-      console.log("Order number:", order.number);
-      console.log("User email:", order.userEmail);
+    if (!orderPayload) {
+      console.error("No order found in webhook payload");
+      return NextResponse.json({ error: "No order in payload" }, { status: 400 });
     }
+    
+    console.log("Order ID:", orderPayload.id);
+    console.log("Order number:", orderPayload.number);
+    console.log("User email:", orderPayload.user_email);
 
     if (!event) {
       return NextResponse.json({ error: "Missing saleor-event header" }, { status: 400 });
@@ -432,10 +530,8 @@ export async function POST(request: NextRequest) {
       return NextResponse.json({ success: true, message: "Event not supported" });
     }
 
-    if (!order) {
-      console.error("No order found in webhook payload");
-      return NextResponse.json({ error: "No order in payload" }, { status: 400 });
-    }
+    // Convert snake_case payload to camelCase
+    const order = convertPayloadToOrder(orderPayload);
 
     await handleSaleorWebhook(normalizedEvent, { order });