实现账号绑定、持久登录与跨设备对局恢复

public/js/skland/scan.js

@@ -0,0 +1,70 @@
+// Serial QR requests: a refresh cannot replace a scan while its confirmation poll is still in flight.
+export const SCAN_POLL_MS = 2_000;
+export const SCAN_REFRESH_MS = 10_000;
+export const SCAN_CONFIRM_REFRESH_MS = 60_000;
+
+export function createQrLogin({ request, encode, onQr, onPending, onError, onConfirmed, onBusy,
+  now = Date.now, timers = globalThis, isHidden = () => false }) {
+  let stopped = false, completed = false, confirmed = false, active = false, busy = false, timer;
+  let ready = false, awaiting = false, manual = true;
+  let refreshAt = Infinity, pollAt = Infinity;
+  const clear = () => { timers.clearTimeout(timer); timer = undefined; };
+  const schedule = () => {
+    clear();
+    if (stopped || completed || !active || busy) return;
+    const due = manual ? now() : ready ? Math.min(refreshAt, pollAt) : refreshAt;
+    timer = timers.setTimeout(tick, isHidden() ? SCAN_POLL_MS : Math.max(0, due - now()));
+  };
+  const generate = async () => {
+    manual = false; ready = false; awaiting = false;
+    // Keep the displayed image until its replacement is encoded; refreshing only changes the existing img's src.
+    onBusy(true); onPending(false); onError(null);
+    try {
+      const result = await request('scan/start', {});
+      if (stopped) return;
+      if (!result.ok || !result.scanUrl) throw new Error(result.error || 'scan_response');
+      const image = await encode(result.scanUrl);
+      if (stopped) return;
+      ready = true; refreshAt = now() + SCAN_REFRESH_MS; pollAt = now() + SCAN_POLL_MS;
+      onQr(image);
+    } finally { if (!stopped) onBusy(false); }
+  };
+  async function tick() {
+    clear();
+    if (stopped || completed || !active || busy) return;
+    if (isHidden()) { schedule(); return; }
+    busy = true;
+    try {
+      if (confirmed) { manual = false; await onConfirmed(); completed = true; }
+      else if (manual || !ready) await generate();
+      else {
+        // Poll once before an automatic refresh too: a just-scanned QR gets its full confirmation window.
+        const result = await request('scan/poll', {});
+        if (stopped) return;
+        if (!result.ok || result.error) throw new Error(result.error || 'scan_response');
+        if (result.state === 'confirmed') {
+          confirmed = true; onQr(null);
+          await onConfirmed();
+          completed = true;
+          return;
+        }
+        if (result.state !== 'waiting') throw new Error('scan_expired');
+        if (result.awaitingConfirmation && !awaiting) {
+          awaiting = true; refreshAt = now() + SCAN_CONFIRM_REFRESH_MS; onPending(true);
+        }
+        pollAt = now() + SCAN_POLL_MS;
+        if (active && !isHidden() && (manual || now() >= refreshAt)) await generate();
+      }
+    } catch (error) {
+      if (!stopped) {
+        ready = false; refreshAt = now() + SCAN_REFRESH_MS;
+        awaiting = false; onPending(false); onQr(null); onError(error);
+      }
+    } finally { busy = false; schedule(); }
+  }
+  return {
+    setActive(value) { active = value; schedule(); },
+    refresh() { manual = true; schedule(); },
+    stop() { stopped = true; clear(); },
+  };
+}