lang

src/lib/groupItemsByDate.ts

@@ -0,0 +1,47 @@
+import {
+  formatChatDateLabel,
+  parseMessageDate,
+} from "@/lib/chat/formatMessageTime";
+import { DEFAULT_LANGUAGE, type AppLanguage } from "@/lib/i18n/registry";
+
+export type DateGroupedItem<T> =
+  | { type: "date"; label: string; key: string }
+  | { type: "item"; item: T; key: string };
+
+function dayKey(createdAt?: string | null): string {
+  const d = parseMessageDate(createdAt);
+  if (d) return d.toDateString();
+  return "unknown-day";
+}
+
+export function groupItemsByDate<T>(
+  items: T[],
+  getCreatedAt: (item: T) => string | null | undefined,
+  getItemKey: (item: T, index: number) => string,
+  lang: AppLanguage = DEFAULT_LANGUAGE
+): DateGroupedItem<T>[] {
+  const groups: DateGroupedItem<T>[] = [];
+  let lastDay = "";
+
+  items.forEach((item, index) => {
+    const createdAt = getCreatedAt(item);
+    const dk = dayKey(createdAt);
+
+    if (dk !== lastDay) {
+      lastDay = dk;
+      groups.push({
+        type: "date",
+        label: formatChatDateLabel(createdAt, lang),
+        key: `date-${dk}`,
+      });
+    }
+
+    groups.push({
+      type: "item",
+      item,
+      key: getItemKey(item, index),
+    });
+  });
+
+  return groups;
+}