feat: retry planning sync automatically (#365)

frontend/dashboard.js

@@ -148,12 +148,13 @@
       refreshMyWorkView();
       warmTodayOffline();
     },
-    onStatus: state => {
+    onStatus: (state, detail = {}) => {
       const status = qs('#today-sync-status');
       status.textContent = state === 'saved' ? 'Today saved to account.' :
-        (state === 'pending' ? 'Today saved on this device · sync pending.' :
+        (state === 'retrying' ? `Today saved on this device · retrying in ${Math.ceil(detail.delayMs / 1000)}s.` :
+          (state === 'pending' ? 'Today saved on this device · sync pending.' :
           (state === 'full' ? 'Another device filled Today · showing its saved plan.' :
-            'Today sync unavailable · changes stay on this device.'));
+            'Today sync unavailable · changes stay on this device.')));
     },
   });
   todaySync.startLifecycle({ window, document });
@@ -180,10 +181,11 @@
       if (!planningOwnerLogin || !laterWork.adopt(records)) return;
       refreshMyWorkView();
     },
-    onStatus: state => {
+    onStatus: (state, detail = {}) => {
       qs('#later-sync-status').textContent = state === 'saved' ? 'Later saved to account.' :
-        (state === 'pending' ? 'Later saved on this device · sync pending.' :
-          'Later sync unavailable · changes stay on this device.');
+        (state === 'retrying' ? `Later saved on this device · retrying in ${Math.ceil(detail.delayMs / 1000)}s.` :
+          (state === 'pending' ? 'Later saved on this device · sync pending.' :
+            'Later sync unavailable · changes stay on this device.'));
     },
   });
   laterSync.startLifecycle({ window, document });
@@ -198,6 +200,8 @@
       const error = new Error(payload.error || payload.detail?.message || payload.detail || 'Review request failed.');
       error.status = response.status;
       error.code = payload.detail?.code;
+      const retryAfter = response.headers.get('Retry-After');
+      error.retryAfter = retryAfter === null ? undefined : Number(retryAfter);
       throw error;
     }
     return payload;

frontend/later-sync.js

@@ -1,10 +1,34 @@
-function createLaterSync({ storage, getLogin, fetchJson, onRemoteRecords, onStatus, createOperationId, createChannel }) {
+function createLaterSync({ storage, getLogin, fetchJson, onRemoteRecords, onStatus, createOperationId, createChannel,
+  setTimer = globalThis.setTimeout, clearTimer = globalThis.clearTimeout, retryBaseMs = 1000, retryMaxMs = 30000 }) {
   const prefix = 'stackchain.later-sync.v1.';
   const migrationPrefix = 'stackchain.later-sync-migrated.v1.';
   const snapshotPrefix = 'stackchain.later-sync-snapshot.v1.';
   let flushing = null;
   let channel = null;
   let channelKey = '';
+  let retryTimer = null;
+  let retryAttempt = 0;
+
+  function cancelRetry() {
+    if (retryTimer !== null) clearTimer?.(retryTimer);
+    retryTimer = null;
+  }
+
+  function scheduleRetry(error, ownerKey) {
+    if (retryTimer !== null || !pending().length || !ownerKey) return;
+    const advised = Number(error?.retryAfter);
+    const delayMs = Number.isFinite(advised) && advised >= 0
+      ? advised * 1000
+      : Math.min(retryMaxMs, retryBaseMs * (2 ** retryAttempt));
+    retryAttempt += 1;
+    onStatus?.('retrying', { delayMs });
+    retryTimer = setTimer?.(async () => {
+      retryTimer = null;
+      if (key() !== ownerKey) return false;
+      return flush();
+    }, delayMs);
+    retryTimer?.unref?.();
+  }
 
   function key() {
     const login = String(getLogin?.() || '').trim().toLowerCase();
@@ -118,12 +142,14 @@ function createLaterSync({ storage, getLogin, fetchJson, onRemoteRecords, onStat
   }
 
   async function run() {
-    if (!key()) return false;
+    const ownerKey = key();
+    if (!ownerKey) return false;
     ensureChannel();
     try {
       let plan = await fetchJson('api/v1/later');
       let operations = pending();
       while (operations.length) {
+        if (key() !== ownerKey) return false;
         const operation = operations[0];
         plan = await fetchJson('api/v1/later', {
           method: 'PATCH',
@@ -139,9 +165,12 @@ function createLaterSync({ storage, getLogin, fetchJson, onRemoteRecords, onStat
       }
       adopt(plan);
       onStatus?.(pending().length ? 'pending' : 'saved');
+      retryAttempt = 0;
+      cancelRetry();
       return true;
-    } catch (_error) {
-      onStatus?.(pending().length ? 'pending' : 'error');
+    } catch (error) {
+      if (pending().length) scheduleRetry(error, ownerKey);
+      else onStatus?.('error');
       return false;
     }
   }

frontend/service-worker.js

@@ -1,6 +1,6 @@
 const BASE = new URL('./', self.location.href).pathname;
 importScripts(BASE + 'static/background-issue-sync.js');
-const CACHE = 'stackchain-dashboard-shell-v48';
+const CACHE = 'stackchain-dashboard-shell-v49';
 const OUTAGE_STATUSES = new Set([500, 502, 503, 504]);
 const NAVIGATION_TIMEOUT_MS = self.__STACKCHAIN_NAVIGATION_TIMEOUT_MS || 4000;
 const SHELL = [

frontend/today-sync.js

@@ -1,10 +1,34 @@
-function createTodaySync({ storage, getLogin, fetchJson, onRemoteIds, onStatus, createOperationId, createChannel }) {
+function createTodaySync({ storage, getLogin, fetchJson, onRemoteIds, onStatus, createOperationId, createChannel,
+  setTimer = globalThis.setTimeout, clearTimer = globalThis.clearTimeout, retryBaseMs = 1000, retryMaxMs = 30000 }) {
   const prefix = 'stackchain.today-sync.v1.';
   const migrationPrefix = 'stackchain.today-sync-migrated.v1.';
   const snapshotPrefix = 'stackchain.today-sync-snapshot.v1.';
   let flushing = null;
   let channel = null;
   let channelKey = '';
+  let retryTimer = null;
+  let retryAttempt = 0;
+
+  function cancelRetry() {
+    if (retryTimer !== null) clearTimer?.(retryTimer);
+    retryTimer = null;
+  }
+
+  function scheduleRetry(error, ownerKey) {
+    if (retryTimer !== null || !pending().length || !ownerKey) return;
+    const advised = Number(error?.retryAfter);
+    const delayMs = Number.isFinite(advised) && advised >= 0
+      ? advised * 1000
+      : Math.min(retryMaxMs, retryBaseMs * (2 ** retryAttempt));
+    retryAttempt += 1;
+    onStatus?.('retrying', { delayMs });
+    retryTimer = setTimer?.(async () => {
+      retryTimer = null;
+      if (key() !== ownerKey) return false;
+      return flush();
+    }, delayMs);
+    retryTimer?.unref?.();
+  }
 
   function key() {
     const login = String(getLogin?.() || '').trim().toLowerCase();
@@ -114,12 +138,14 @@ function createTodaySync({ storage, getLogin, fetchJson, onRemoteIds, onStatus,
   }
 
   async function run() {
-    if (!key()) return false;
+    const ownerKey = key();
+    if (!ownerKey) return false;
     ensureChannel();
     try {
       let plan = await fetchJson('api/v1/today');
       const operations = pending();
       for (const operation of operations) {
+        if (key() !== ownerKey) return false;
         try {
           plan = await fetchJson('api/v1/today', {
             method: 'PATCH',
@@ -132,6 +158,8 @@ function createTodaySync({ storage, getLogin, fetchJson, onRemoteIds, onStatus,
           save(rejected.filter(candidate => candidate.operation_id !== operation.operation_id));
           adopt(plan);
           onStatus?.('full');
+          retryAttempt = 0;
+          cancelRetry();
           return false;
         }
         const remaining = pending();
@@ -139,9 +167,12 @@ function createTodaySync({ storage, getLogin, fetchJson, onRemoteIds, onStatus,
       }
       adopt(plan);
       onStatus?.(pending().length ? 'pending' : 'saved');
+      retryAttempt = 0;
+      cancelRetry();
       return true;
-    } catch (_error) {
-      onStatus?.(pending().length ? 'pending' : 'error');
+    } catch (error) {
+      if (pending().length) scheduleRetry(error, ownerKey);
+      else onStatus?.('error');
       return false;
     }
   }