fix: add rate limiting with retry on 429 in sync-stock

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/app/api/creation/sync-stock/route.ts

@@ -80,19 +80,28 @@ export async function POST(req: NextRequest) {
         let updated = 0
         let errors = 0
 
+        const sleep = (ms: number) => new Promise(r => setTimeout(r, ms))
+
+        const shopifyFetch = async (url: string, opts: RequestInit, retries = 3): Promise<Response> => {
+          const res = await fetch(url, opts)
+          if (res.status === 429 && retries > 0) {
+            const retryAfter = parseInt(res.headers.get('Retry-After') ?? '2', 10)
+            await sleep(retryAfter * 1000)
+            return shopifyFetch(url, opts, retries - 1)
+          }
+          return res
+        }
+
         for (let i = 0; i < entries.length; i++) {
           const { shopifyId, stock, title } = entries[i]
           send({ type: 'progress', current: i + 1, total: entries.length, title })
           try {
-            // Récupérer le variant pour obtenir inventory_item_id
-            const pRes = await fetch(`${baseUrl}/products/${shopifyId}.json?fields=variants`, { headers })
-            if (pRes.status === 404) {
-              // Produit supprimé de Shopify, on ignore silencieusement
-              continue
-            }
+            await sleep(300) // éviter le rate limiting (2 req/s max)
+
+            const pRes = await shopifyFetch(`${baseUrl}/products/${shopifyId}.json?fields=variants`, { headers })
+            if (pRes.status === 404) continue
             if (!pRes.ok) {
-              const msg = `Produit ${shopifyId} erreur (${pRes.status})`
-              send({ type: 'error', title, message: msg })
+              send({ type: 'error', title, message: `Produit ${shopifyId} erreur (${pRes.status})` })
               errors++
               continue
             }
@@ -100,13 +109,14 @@ export async function POST(req: NextRequest) {
             const inventoryItemId = pData.product.variants[0]?.inventory_item_id
             if (!inventoryItemId) { errors++; continue }
 
-            // Connect (idempotent)
-            await fetch(`${baseUrl}/inventory_levels/connect.json`, {
+            await sleep(300)
+            await shopifyFetch(`${baseUrl}/inventory_levels/connect.json`, {
               method: 'POST', headers,
               body: JSON.stringify({ location_id: locationId, inventory_item_id: inventoryItemId }),
             })
 
-            const setRes = await fetch(`${baseUrl}/inventory_levels/set.json`, {
+            await sleep(300)
+            const setRes = await shopifyFetch(`${baseUrl}/inventory_levels/set.json`, {
               method: 'POST', headers,
               body: JSON.stringify({ location_id: locationId, inventory_item_id: inventoryItemId, available: stock }),
             })