feat: warn when the local clock is far off the homeserver's (#158)

Incident 2026-09-17: a wrong Windows clock broke calls and media keys while the server answered 200 to everything, with no hint in the UI. Measurement needs no extra requests and no CORS-exposed headers: every live event carries origin_server_ts and unsigned.age (our server's now − ts at response time), so localTimestamp − origin_server_ts is the skew. Only RoomEvent.Timeline live events count (cache replays have stale age and are already flagged liveEvent=false by the SDK); the initial network sync qualifies, so a wrong clock is flagged within seconds of startup. Median of the last 5 samples, ≥3 needed; warn at |skew| > 30 s, clear below 15 s. UI: a banner in the sync-status slot — "Your computer's clock is 14 minutes ahead of the server. Encrypted messages and voice calls will fail until it is fixed." with a per-OS How-to-fix hint and Dismiss for 24 h — plus the same line in the call status bar while in a call. Never auto-corrects anything. Unit-tested (median, hysteresis, stale-age rejection, wording); verified headless with Playwright's clock skewed +14 min and −3 h (banner, hint, in-call line, dismiss) and in sync (nothing shown). Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01PPmy3tPq869XDW4njjVaKA
2026-09-19 12:52:03 -04:00
parent 464951edf4
commit 84c906fe33
7 changed files with 372 additions and 1 deletions
@@ -0,0 +1,82 @@
+import React, { useCallback, useState } from 'react';
+import { useAtomValue } from 'jotai';
+import { Box, Button, config, Line, Text } from 'folds';
+import { clockSkewAtom } from '../../state/clockSkew';
+import { ContainerColor } from '../../styles/ContainerColor.css';
+import { clockFixHint, describeSkewVsServer, detectClockFixPlatform } from '../../utils/clockSkew';
+
+const DISMISS_KEY = 'lotus-clock-skew-dismissed-until';
+const DISMISS_MS = 24 * 60 * 60 * 1000;
+
+const readDismissedUntil = (): number => {
+  try {
+    const raw = localStorage.getItem(DISMISS_KEY);
+    const n = raw ? Number(raw) : 0;
+    return Number.isFinite(n) ? n : 0;
+  } catch {
+    return 0;
+  }
+};
+
+/**
+ * [Gitea #158] "Your computer's clock is 14 minutes ahead of the server."
+ * Same slot and style as the sync banners. Shown while the skew monitor is
+ * over its threshold; the direction matters, so it is said. Dismissable for
+ * 24 h; never auto-corrects anything.
+ */
+export function ClockSkewBanner() {
+  const { skewMs, warning } = useAtomValue(clockSkewAtom);
+  const [dismissedUntil, setDismissedUntil] = useState(readDismissedUntil);
+  const [showHint, setShowHint] = useState(false);
+
+  const dismiss = useCallback(() => {
+    const until = Date.now() + DISMISS_MS;
+    try {
+      localStorage.setItem(DISMISS_KEY, String(until));
+    } catch {
+      // storage unavailable — dismiss for this session only
+    }
+    setDismissedUntil(until);
+  }, []);
+
+  if (!warning || skewMs === null || Date.now() < dismissedUntil) return null;
+
+  return (
+    <Box direction="Column" shrink="No">
+      <Box
+        className={ContainerColor({ variant: 'Warning' })}
+        style={{ padding: `${config.space.S100} ${config.space.S300}` }}
+        direction="Column"
+        alignItems="Center"
+        gap="100"
+        role="alert"
+      >
+        <Box alignItems="Center" gap="300" wrap="Wrap" justifyContent="Center">
+          <Text size="L400" align="Center">
+            Your computer&apos;s clock is <b>{describeSkewVsServer(skewMs)}</b>. Encrypted messages
+            and voice calls will fail until it is fixed.
+          </Text>
+          <Button
+            size="300"
+            variant="Warning"
+            fill="Soft"
+            radii="300"
+            onClick={() => setShowHint((v) => !v)}
+            aria-expanded={showHint}
+          >
+            <Text size="B300">How to fix</Text>
+          </Button>
+          <Button size="300" variant="Warning" fill="None" radii="300" onClick={dismiss}>
+            <Text size="B300">Dismiss for 24 h</Text>
+          </Button>
+        </Box>
+        {showHint && (
+          <Text size="T200" align="Center">
+            {clockFixHint(detectClockFixPlatform(navigator.userAgent))}
+          </Text>
+        )}
+      </Box>
+      <Line variant="Warning" size="300" />
+    </Box>
+  );
+}