first commit

src/auth/activity.ts

@@ -0,0 +1,24 @@
+const key = 'safety-last-activity-at'
+const throttleMs = 30_000
+
+export const activity = {
+  get: () => Number(localStorage.getItem(key) || 0),
+  record(force = false) {
+    const now = Date.now()
+    if (force || now - this.get() >= throttleMs) localStorage.setItem(key, String(now))
+  },
+  clear: () => localStorage.removeItem(key),
+  start(checkRefresh: () => void) {
+    const onActivity = () => { this.record(); checkRefresh() }
+    const onVisible = () => { if (document.visibilityState === 'visible') checkRefresh() }
+    const events = ['click', 'keydown', 'touchstart'] as const
+    events.forEach((event) => window.addEventListener(event, onActivity, { passive: true }))
+    window.addEventListener('popstate', onActivity)
+    document.addEventListener('visibilitychange', onVisible)
+    return () => {
+      events.forEach((event) => window.removeEventListener(event, onActivity))
+      window.removeEventListener('popstate', onActivity)
+      document.removeEventListener('visibilitychange', onVisible)
+    }
+  },
+}