create a jwt token if there is a customerId, move the get customer id to the main utils folder. Need to add in more value to the env file. Updated the env sample.

framework/bigcommerce/api/endpoints/checkout/checkout.ts

@@ -1,4 +1,7 @@
 import type { CheckoutEndpoint } from '.'
+import getCustomerId from '../../utils/get-customer-id'
+import jwt from 'jsonwebtoken'
+import { uuid } from 'uuidv4'
 
 const fullCheckout = true
 
@@ -9,21 +12,44 @@ const checkout: CheckoutEndpoint['handlers']['checkout'] = async ({
 }) => {
   const { cookies } = req
   const cartId = cookies[config.cartCookie]
+  const customerToken = cookies[config.customerCookie]
+  let checkouturl: string
 
   if (!cartId) {
     res.redirect('/cart')
     return
   }
-
   const { data } = await config.storeApiFetch(
     `/v3/carts/${cartId}/redirect_urls`,
     {
       method: 'POST',
     }
   )
+  const customerId =
+    customerToken && (await getCustomerId({ customerToken, config }))
+  //if there is a customer create a jwt token
+  if (customerId >= 0) {
+    const dateCreated = Math.round(new Date().getTime() / 1000)
+    const payload = {
+      iss: config.storeApiClientId,
+      iat: dateCreated,
+      jti: uuid(),
+      operation: 'customer_login',
+      store_hash: config.storeHash,
+      customer_id: customerId,
+      channel_id: config.storeChannelId,
+      redirect_to: data.checkout_url,
+    }
+    let token = jwt.sign(payload, config.storeApiClientSecret, {
+      algorithm: 'HS256',
+    })
+    checkouturl = `${config.storeUrl}/login/token/${token}`
+  } else {
+    checkouturl = data.checkout_url
+  }
 
   if (fullCheckout) {
-    res.redirect(data.checkout_url)
+    res.redirect(checkouturl)
     return
   }