feat: real Brevo API verifier, auto-reset if campaign missing, and update existing campaign support

src/app/page.tsx

@@ -370,7 +370,7 @@ export default function Home() {
     saveAs(blob, `coop-newsletter-${new Date().toISOString().split('T')[0]}.zip`);
   };
 
-  const handleExportBrevo = async () => {
+  const handleExportBrevo = async (updateExisting = false) => {
     setIsExportingBrevo(true);
     try {
       const rawHtml = renderEmailHtml(campaign);
@@ -391,14 +391,22 @@ export default function Home() {
         body: JSON.stringify({
           campaignName: `${campaign.title} - ${new Date().toLocaleDateString('sk-SK')}`,
           subject: campaign.title,
-          htmlContent: finalHtml
+          htmlContent: finalHtml,
+          updateExisting: updateExisting,
+          existingCampaignId: campaign.brevoCampaignId
         })
       });
 
       const resData = await response.json();
 
       if (resData.success && resData.campaignId) {
+        setCampaign((prev) => ({
+          ...prev,
+          brevoCampaignId: resData.campaignId,
+          status: 'exported'
+        }));
         setBrevoUrl(resData.brevoUrl);
+
         if (campaign.id) {
           await supabase
             .from('templates')
@@ -408,7 +416,12 @@ export default function Home() {
             })
             .eq('id', campaign.id);
         }
-        alert('Kampaň bola úspešne odoslaná do Brevo!');
+        alert(
+          resData.message ||
+            (updateExisting
+              ? 'Kampaň bola v Brevo úspešne aktualizovaná!'
+              : 'Kampaň bola úspešne odoslaná do Brevo!')
+        );
       } else {
         alert(`Chyba pri exporte do Brevo: ${resData.error || 'Neznáma chyba'}`);
       }
@@ -419,6 +432,17 @@ export default function Home() {
     }
   };
 
+  const handleClearBrevoId = async () => {
+    setCampaign((prev) => ({ ...prev, brevoCampaignId: undefined }));
+    setBrevoUrl(null);
+    if (campaign.id) {
+      await supabase
+        .from('templates')
+        .update({ brevo_campaign_id: null })
+        .eq('id', campaign.id);
+    }
+  };
+
   // Vybraný produkt pre editor cenoviek
   let targetProduct: ProductItem | null = null;
   if (targetProductIdForBadge && selectedModule?.data?.products) {
@@ -465,6 +489,7 @@ export default function Home() {
         isExportingBrevo={isExportingBrevo}
         brevoCampaignUrl={brevoUrl}
         brevoListingUrl="https://app.brevo.com/campaigns/listing"
+        onClearBrevoId={handleClearBrevoId}
         onAddModule={handleAddModule}
       />