update and fix messanger

apps/frontend/lib/chat-date-utils.ts

@@ -0,0 +1,33 @@
+export function getChatDateKey(value: string | Date) {
+  const date = typeof value === 'string' ? new Date(value) : value;
+  return `${date.getFullYear()}-${date.getMonth()}-${date.getDate()}`;
+}
+
+export function formatChatDateLabel(value: string, now = new Date()) {
+  const date = new Date(value);
+  const today = new Date(now.getFullYear(), now.getMonth(), now.getDate());
+  const target = new Date(date.getFullYear(), date.getMonth(), date.getDate());
+  const diffDays = Math.round((today.getTime() - target.getTime()) / 86_400_000);
+
+  if (diffDays === 0) return 'Сегодня';
+  if (diffDays === 1) return 'Вчера';
+
+  return new Intl.DateTimeFormat('ru-RU', {
+    day: '2-digit',
+    month: '2-digit',
+    year: 'numeric'
+  }).format(date);
+}
+
+export function shouldShowChatDateSeparator(currentCreatedAt: string, previousCreatedAt?: string) {
+  if (!previousCreatedAt) return true;
+  return getChatDateKey(currentCreatedAt) !== getChatDateKey(previousCreatedAt);
+}
+
+export function toDateInputValue(value: string) {
+  const date = new Date(value);
+  const year = date.getFullYear();
+  const month = String(date.getMonth() + 1).padStart(2, '0');
+  const day = String(date.getDate()).padStart(2, '0');
+  return `${year}-${month}-${day}`;
+}