feat: improve audit exports and admin analytics

ai_knowledge_base_v2/apps/user-client/src/utils/dateTime.ts

@@ -0,0 +1,76 @@
+export const BUSINESS_TIME_ZONE = "Asia/Shanghai";
+const BUSINESS_OFFSET = "+08:00";
+const DATE_ONLY_PATTERN = /^\d{4}-\d{2}-\d{2}$/;
+const EXPLICIT_OFFSET_PATTERN = /(?:Z|[+-]\d{2}:?\d{2})$/i;
+
+export function parseApiDateTime(value?: string | Date | null): Date | null {
+  if (!value) return null;
+  if (value instanceof Date) return Number.isNaN(value.getTime()) ? null : value;
+  const text = value.trim();
+  if (!text) return null;
+  const isoText = text.includes(" ") ? text.replace(" ", "T") : text;
+  const normalized = DATE_ONLY_PATTERN.test(isoText)
+    ? `${isoText}T00:00:00${BUSINESS_OFFSET}`
+    : EXPLICIT_OFFSET_PATTERN.test(isoText)
+      ? isoText
+      : `${isoText}Z`;
+  const parsed = new Date(normalized);
+  return Number.isNaN(parsed.getTime()) ? null : parsed;
+}
+
+function businessParts(value?: string | Date | null) {
+  const parsed = parseApiDateTime(value);
+  if (!parsed) return null;
+  const parts = new Intl.DateTimeFormat("zh-CN", {
+    timeZone: BUSINESS_TIME_ZONE,
+    year: "numeric",
+    month: "2-digit",
+    day: "2-digit",
+    hour: "2-digit",
+    minute: "2-digit",
+    second: "2-digit",
+    hour12: false,
+    hourCycle: "h23",
+  }).formatToParts(parsed);
+  return Object.fromEntries(parts.map((part) => [part.type, part.value]));
+}
+
+export function formatDate(value?: string | Date | null, fallback = "-") {
+  const parts = businessParts(value);
+  return parts ? `${parts.year}-${parts.month}-${parts.day}` : fallback;
+}
+
+export function formatTime(value?: string | Date | null, fallback = "-") {
+  const parts = businessParts(value);
+  return parts ? `${parts.hour}:${parts.minute}` : fallback;
+}
+
+export function formatDateTime(value?: string | Date | null, fallback = "-") {
+  const parts = businessParts(value);
+  return parts
+    ? `${parts.year}-${parts.month}-${parts.day} ${parts.hour}:${parts.minute}:${parts.second}`
+    : fallback;
+}
+
+export function businessDateKey(value?: string | Date | null): string | null {
+  const parts = businessParts(value);
+  return parts ? `${parts.year}-${parts.month}-${parts.day}` : null;
+}
+
+export function formatSessionTime(
+  value?: string | Date | null,
+  now: Date = new Date(),
+): string {
+  const targetKey = businessDateKey(value);
+  const todayKey = businessDateKey(now);
+  const time = formatTime(value, "");
+  if (!targetKey || !todayKey || !time) return "";
+  const dayNumber = (key: string) => {
+    const [year, month, day] = key.split("-").map(Number);
+    return Date.UTC(year, month - 1, day) / 86_400_000;
+  };
+  const days = dayNumber(todayKey) - dayNumber(targetKey);
+  if (days === 0) return time;
+  if (days === 1) return `昨天 ${time}`;
+  return `${targetKey.slice(5).replace("-", "/")} ${time}`;
+}