fix: retry 429 avec backoff + sérialisation uploadAll + 409 traité comme skipped

src/lib/shopify.ts

@@ -118,20 +118,41 @@ export async function uploadProductImage(
   const existingUrl = await productImageExists(shopifyProductId, filename)
   if (existingUrl) return { url: existingUrl, skipped: true }
 
-  const res = await fetch(`${baseUrl}/products/${shopifyProductId}/images.json`, {
-    method: 'POST',
-    headers,
-    body: JSON.stringify({ image: { attachment: imageBase64, filename } }),
-  })
+  // Retry avec backoff exponentiel (gère le 429 rate limit)
+  const MAX_RETRIES = 4
+  let delay = 1000
 
-  if (!res.ok) {
-    const body = await res.text()
-    throw new Error(`Shopify upload error: ${res.status} — ${body}`)
+  for (let attempt = 0; attempt <= MAX_RETRIES; attempt++) {
+    const res = await fetch(`${baseUrl}/products/${shopifyProductId}/images.json`, {
+      method: 'POST',
+      headers,
+      body: JSON.stringify({ image: { attachment: imageBase64, filename } }),
+    })
+
+    // 409 Conflict = image déjà présente → traiter comme skipped
+    if (res.status === 409) {
+      return { url: `https://placeholder/already-exists/${filename}`, skipped: true }
+    }
+
+    // 429 Too Many Requests → attendre et réessayer
+    if (res.status === 429 && attempt < MAX_RETRIES) {
+      const retryAfter = parseInt(res.headers.get('Retry-After') ?? '0', 10)
+      await new Promise(r => setTimeout(r, retryAfter > 0 ? retryAfter * 1000 : delay))
+      delay *= 2
+      continue
+    }
+
+    if (!res.ok) {
+      const body = await res.text()
+      throw new Error(`Shopify upload error: ${res.status} — ${body}`)
+    }
+
+    const data = await res.json()
+    if (!data.image?.src) {
+      throw new Error('Shopify response invalide : champ image.src manquant')
+    }
+    return { url: data.image.src as string }
   }
 
-  const data = await res.json()
-  if (!data.image?.src) {
-    throw new Error('Shopify response invalide : champ image.src manquant')
-  }
-  return { url: data.image.src as string }
+  throw new Error('Shopify upload error: trop de tentatives (rate limit persistant)')
 }