Fix federated interactions and reply threads

src/lib/utils/federation.ts

@@ -0,0 +1,32 @@
+import { z } from 'zod';
+
+const localHandlePattern = /^[a-zA-Z0-9_]{3,20}$/;
+const hostnameLabel = '[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?';
+const nodeDomainPattern = `(?:localhost|127\\.0\\.0\\.1|${hostnameLabel}(?:\\.${hostnameLabel})+)(?::\\d{1,5})?`;
+const federatedHandlePattern = new RegExp(`^[a-zA-Z0-9_]{3,20}(?:@${nodeDomainPattern})?$`);
+const nodeDomainRegex = new RegExp(`^${nodeDomainPattern}$`);
+
+export const localHandleSchema = z
+  .string()
+  .min(3)
+  .max(20)
+  .regex(localHandlePattern, 'Handle must be 3-20 characters, alphanumeric and underscores only');
+
+export const federatedHandleSchema = z
+  .string()
+  .min(3)
+  .max(255)
+  .regex(
+    federatedHandlePattern,
+    'Handle must be a local handle or a federated handle like user@example.com'
+  );
+
+export const nodeDomainSchema = z
+  .string()
+  .min(1)
+  .max(255)
+  .regex(nodeDomainRegex, 'Invalid node domain format');
+
+export function isValidNodeDomain(value: string): boolean {
+  return nodeDomainRegex.test(value);
+}