feat: écriture de l'ID Shopify en col A du Sheets après création produit

Utilise un compte de service Google avec JWT pour authentifier les écritures
dans le Sheets — sans dépendance npm supplémentaire (crypto natif Node.js).

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

src/app/api/creation/execute/route.ts

@@ -1,7 +1,7 @@
 import { NextRequest } from 'next/server'
 import { getServerSession } from 'next-auth'
 import { authOptions } from '@/lib/auth'
-import { fetchPendingProducts } from '@/lib/creationSheets'
+import { fetchPendingProducts, writeShopifyIdToSheet } from '@/lib/creationSheets'
 import { generateDescriptions } from '@/lib/openaiClient'
 import { ensureMetafieldDefinition, setProductMetafield } from '@/lib/shopifyMetafields'
 import { addProductToCollection } from '@/lib/shopifyCollections'
@@ -92,6 +92,7 @@ export async function POST(req: NextRequest) {
             await prisma.productCreation.create({
               data: { userId, sheetTab: product.tab, sheetRow: product.rowNumber, shopifyId, sku: product.sku, title: product.title, status: 'success' },
             })
+            await writeShopifyIdToSheet(product.tab, product.rowNumber, shopifyId)
             created++
           } catch (err) {
             const message = err instanceof Error ? err.message : 'Erreur inconnue'

src/lib/creationSheets.ts

@@ -80,6 +80,53 @@ export function parseTabRows(tab: string, headers: string[], rows: string[][], d
     .filter((p): p is PendingProduct => p !== null)
 }
 
+/**
+ * Écrit l'ID Shopify en colonne A de la ligne correspondante dans Google Sheets.
+ * Utilise un compte de service avec accès éditeur sur la feuille.
+ */
+export async function writeShopifyIdToSheet(tab: string, rowNumber: number, shopifyId: string): Promise<void> {
+  const sheetId = process.env.GOOGLE_SHEETS_ID
+  const email = process.env.GOOGLE_SERVICE_ACCOUNT_EMAIL
+  const rawKey = process.env.GOOGLE_SERVICE_ACCOUNT_KEY
+  if (!sheetId || !email || !rawKey) return
+
+  // Génère un JWT pour l'authentification Google
+  const privateKey = rawKey.replace(/\\n/g, '\n')
+  const now = Math.floor(Date.now() / 1000)
+  const header = Buffer.from(JSON.stringify({ alg: 'RS256', typ: 'JWT' })).toString('base64url')
+  const payload = Buffer.from(JSON.stringify({
+    iss: email,
+    scope: 'https://www.googleapis.com/auth/spreadsheets',
+    aud: 'https://oauth2.googleapis.com/token',
+    iat: now,
+    exp: now + 3600,
+  })).toString('base64url')
+
+  const { createSign } = await import('crypto')
+  const sign = createSign('RSA-SHA256')
+  sign.update(`${header}.${payload}`)
+  const signature = sign.sign(privateKey, 'base64url')
+  const jwt = `${header}.${payload}.${signature}`
+
+  const tokenRes = await fetch('https://oauth2.googleapis.com/token', {
+    method: 'POST',
+    headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
+    body: new URLSearchParams({ grant_type: 'urn:ietf:params:oauth:grant-type:jwt-bearer', assertion: jwt }),
+  })
+  if (!tokenRes.ok) return
+  const { access_token } = await tokenRes.json() as { access_token: string }
+
+  const range = encodeURIComponent(`${tab}!A${rowNumber}`)
+  await fetch(
+    `https://sheets.googleapis.com/v4/spreadsheets/${sheetId}/values/${range}?valueInputOption=RAW`,
+    {
+      method: 'PUT',
+      headers: { Authorization: `Bearer ${access_token}`, 'Content-Type': 'application/json' },
+      body: JSON.stringify({ range: `${tab}!A${rowNumber}`, majorDimension: 'ROWS', values: [[shopifyId]] }),
+    },
+  )
+}
+
 export async function fetchPendingProducts(
   alreadyCreatedRows: Set<string>,
   tabFilter?: string,