campaign sending prototype

webui/src/utils/datetime.ts

@@ -0,0 +1,46 @@
+const HAS_TIMEZONE_OFFSET = /(?:Z|[+-]\d{2}:?\d{2})$/i;
+
+function normalizeServerDateTime(value: string): string {
+  const trimmed = value.trim();
+  if (!trimmed) return trimmed;
+  return HAS_TIMEZONE_OFFSET.test(trimmed) ? trimmed : `${trimmed}Z`;
+}
+
+export function parseServerDateTime(value?: string | null): Date | null {
+  if (!value) return null;
+  const date = new Date(normalizeServerDateTime(value));
+  return Number.isNaN(date.getTime()) ? null : date;
+}
+
+export type FormatDateTimeOptions = Intl.DateTimeFormatOptions & {
+  fallback?: string;
+};
+
+export const defaultDateTimeFormatOptions: Intl.DateTimeFormatOptions = {
+  year: "numeric",
+  month: "short",
+  day: "2-digit",
+  hour: "2-digit",
+  minute: "2-digit",
+  timeZoneName: "short"
+};
+
+export function formatDateTime(value?: string | null, options: FormatDateTimeOptions = {}): string {
+  const fallback = options.fallback ?? "—";
+  if (!value) return fallback;
+  const date = parseServerDateTime(value);
+  if (!date) return value;
+  const { fallback: _fallback, ...intlOptions } = options;
+  return date.toLocaleString(undefined, {
+    ...defaultDateTimeFormatOptions,
+    ...intlOptions
+  });
+}
+
+export function formatDateTimeFromDate(value: Date, options: FormatDateTimeOptions = {}): string {
+  const { fallback: _fallback, ...intlOptions } = options;
+  return value.toLocaleString(undefined, {
+    ...defaultDateTimeFormatOptions,
+    ...intlOptions
+  });
+}