feat(hackathon): draft winner certificate

apps/hackathon/src/utils/certificate.ts

@@ -15,6 +15,16 @@ export const encodeCertificateId = async (teamId: string, submissionId: string,
   return encryptText(combined, SECRET_KEY);
 };
 
+/**
+ * Encode winner certificate ID (team-based)
+ * @param teamId - Winner team ID
+ * @returns Encoded winner certificate ID
+ */
+export const encodeWinnerCertificateId = async (teamId: string): Promise<string> => {
+  const combined = `winner::${teamId}`;
+  return encryptText(combined, SECRET_KEY);
+};
+
 /**
  * Decode certificate ID back to teamId, submissionId, and userId
  * @param certId - The encoded certificate ID
@@ -40,6 +50,27 @@ export const decodeCertificateId = async (certId: string): Promise<{ teamId: str
   }
 };
 
+/**
+ * Decode winner certificate ID back to teamId
+ * @param certId - The encoded winner certificate ID
+ * @returns Object containing teamId
+ */
+export const decodeWinnerCertificateId = async (certId: string): Promise<{ teamId: string }> => {
+  try {
+    const decoded = await decryptText(certId, SECRET_KEY);
+    const parts = decoded.split('::');
+
+    // winner::teamId
+    if (parts.length === 2 && parts[0] === 'winner') {
+      return { teamId: parts[1] };
+    }
+
+    throw new Error('Invalid winner certificate format');
+  } catch {
+    throw new Error('Invalid certificate ID');
+  }
+};
+
 /**
  * For development: Create a certId using created_at timestamp
  * @param teamId - The team ID