fix(sync): 数据同步合并化 + 排行榜缓存与游标分页

- storage: 新增 mergeRecords,云端记录与本地按 id 去重合并,restore
  不再覆盖,解决训练中冷启动丢记录与多设备记录丢失
- storage: 新增 recomputeStreak,restore 后基于合并记录重算 streak,
  不再信任云端 streak 值
- storage: 新增 _local_changed_at 标记,settings/profile/customPlans
  在本地有未同步改动时保留本地,避免被云端旧值覆盖
- app: _restoreFromCloud 改合并 + 时间戳保护 + streak 重算;Case 2
  合并后回推让两端收敛
- leaderboard: 模块级 60s 缓存 + 游标分页(_id > lastId)替代 skip,
  全表扫描从每次打开降到 60s 内一次

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

app.js

@@ -67,14 +67,17 @@ App({
 
         if (!hasLocal && hasCloud) {
           // Case 1: Fresh install on a new device — restore from cloud
-          this._restoreFromCloud(cloudData)
+          this._restoreFromCloud(cloudData, cloudTs)
           wx.setStorageSync('_cloud_sync_at', cloudTs)
         } else if (hasLocal && hasCloud) {
           // Case 2: Both sides have data — compare timestamps
           if (cloudTs > localSyncAt) {
-            // Cloud is newer (another device synced after our last push)
-            this._restoreFromCloud(cloudData)
+            // Cloud is newer (another device synced after our last push).
+            // Merge cloud into local, then push the merged result back so
+            // both sides converge (records union + local's unsynced edits).
+            this._restoreFromCloud(cloudData, cloudTs)
             wx.setStorageSync('_cloud_sync_at', cloudTs)
+            cloud.pushAll()
           } else {
             // Local is at least as current — push
             cloud.pushAll()
@@ -90,26 +93,33 @@ App({
     }
   },
 
-  _restoreFromCloud(cloudData) {
+  _restoreFromCloud(cloudData, cloudTs) {
     if (!cloudData) return
     try {
-      if (cloudData.records && Object.keys(cloudData.records).length > 0) {
-        // Guard: only restore if at least one month has actual records.
-        // Pre-6d19928 duplicates could leave docs with month keys but
-        // empty arrays, which would wipe local data on restore.
-        const hasAny = Object.values(cloudData.records).some(
+      // Records: MERGE instead of overwrite. A training saved during the
+      // async pullAll (or edits from another device) would otherwise be
+      // wiped by the cloud's older snapshot.
+      if (cloudData.records) {
+        const merged = storage.mergeRecords(cloudData.records)
+        const hasAny = Object.values(merged).some(
           arr => Array.isArray(arr) && arr.length > 0
         )
         if (hasAny) {
-          wx.setStorageSync('training_records', cloudData.records)
+          wx.setStorageSync('training_records', merged)
         }
       }
+
+      // Single-value fields: only adopt the cloud version if the local
+      // side hasn't changed since the cloud snapshot. Otherwise we'd
+      // clobber unsynced local edits (e.g. a setting flipped mid-sync).
+      const localChangedAt = wx.getStorageSync('_local_changed_at') || 0
+      const keepLocal = cloudTs > 0 && localChangedAt > cloudTs
+      if (keepLocal) {
+        console.log('[cloud] restore: keeping local single-value fields (local changed after cloud snapshot)')
+      } else {
         if (cloudData.settings) {
           wx.setStorageSync('user_settings', cloudData.settings)
         }
-      if (cloudData.streak) {
-        wx.setStorageSync('current_streak', cloudData.streak)
-      }
         if (cloudData.customPlans && typeof cloudData.customPlans === 'object') {
           wx.setStorageSync('custom_plans', cloudData.customPlans)
         }
@@ -119,6 +129,11 @@ App({
         if (cloudData.themeId) {
           themeMod.setTheme(cloudData.themeId)
         }
+      }
+
+      // Streak: never trust the cloud value - recompute from the merged
+      // records so it reflects actual history on this device.
+      storage.recomputeStreak()
     } catch (e) {
       console.error('Cloud restore failed:', e)
     }

cloudfunctions/leaderboard/index.js

@@ -15,6 +15,59 @@ const pad = (n) => String(n).padStart(2, '0')
 // other timezones, switch back to a client-provided date.
 const TZ_OFFSET_MS = 8 * 60 * 60 * 1000
 
+// In-instance cache of the latest doc per openid. The full-collection
+// scan + dedup is the expensive part of building the board; cache it for
+// a short TTL so repeated board opens (and day/month/year switches within
+// a session) reuse one scan. Cold starts just re-scan. Not persistent
+// across instances, which is fine - the board needn't be real-time.
+const CACHE_TTL = 60 * 1000
+let _docsCache = null  // { latestByOpenid: Map, ts }
+
+const tsOf = (d) => {
+  if (!d.updatedAt) return 0
+  // CloudBase returns Date objects in the SDK, but be defensive in case
+  // a stringified ISO timestamp sneaks through (older SDKs / migrations).
+  if (d.updatedAt instanceof Date) return d.updatedAt.getTime()
+  const t = new Date(d.updatedAt).getTime()
+  return Number.isFinite(t) ? t : 0
+}
+
+// Page through the collection keeping only the most-recently-updated doc
+// per openid. Uses cursor pagination (_id > lastId) instead of skip(N):
+// skip is O(N) and degrades as the collection grows; a cursor is constant
+// cost per page, and default get() order (_id ascending) won't drop/dup.
+const _fetchLatestByOpenid = async () => {
+  if (_docsCache && (Date.now() - _docsCache.ts) < CACHE_TTL) {
+    return _docsCache.latestByOpenid
+  }
+  const latestByOpenid = new Map()
+  // Exclude accounts that haven't synced in 90+ days to bound the scan.
+  // Docs without an updatedAt field (pre-fix legacy) are included as well.
+  const ninetyDaysAgo = new Date(Date.now() - 90 * 24 * 60 * 60 * 1000)
+  let lastId = ''
+  while (true) {
+    const cond = lastId
+      ? _.and([
+          _.or([{ updatedAt: _.gte(ninetyDaysAgo) }, { updatedAt: _.exists(false) }]),
+          { _id: _.gt(lastId) }
+        ])
+      : _.or([{ updatedAt: _.gte(ninetyDaysAgo) }, { updatedAt: _.exists(false) }])
+    const res = await db.collection(COLLECTION).where(cond).limit(PAGE_SIZE).get()
+    if (!res.data || res.data.length === 0) break
+    for (const doc of res.data) {
+      const openid = doc._openid || 'unknown'
+      const current = latestByOpenid.get(openid)
+      if (!current || tsOf(doc) > tsOf(current)) {
+        latestByOpenid.set(openid, doc)
+      }
+    }
+    if (res.data.length < PAGE_SIZE) break
+    lastId = res.data[res.data.length - 1]._id
+  }
+  _docsCache = { latestByOpenid, ts: Date.now() }
+  return latestByOpenid
+}
+
 exports.main = async (event) => {
   const { period, maxRank } = event || {}
   const limit = Math.max(1, Math.min(parseInt(maxRank) || DEFAULT_MAX_RANK, 500))
@@ -36,57 +89,13 @@ exports.main = async (event) => {
   else return { err: 'invalid period' }
 
   const userMap = new Map()
-  let skip = 0
 
-  // Defense-in-depth: if a user somehow ends up with multiple docs in the
-  // collection (e.g. before the client-side fix to _doPush landed, or via
-  // a buggy data migration), only the doc with the latest `updatedAt`
-  // counts for each openid. Otherwise we'd sum the same records N times
-  // and inflate the board.
-  //
-  // Why "latest updatedAt" instead of "first one we see": paginated reads
-  // come back in `_id` ascending order, so "first one" is the OLDEST doc.
-  // Records content is identical across duplicates (both came from the
-  // same local state), so duration/sessions are unaffected — but the
-  // oldest doc carries the OLDEST profile.nickname. Picking the latest
-  // doc gives the freshest nickname even before admin-dedupe runs.
-  const tsOf = (d) => {
-    if (!d.updatedAt) return 0
-    // CloudBase returns Date objects in the SDK, but be defensive in case
-    // a stringified ISO timestamp sneaks through (older SDKs / migrations).
-    if (d.updatedAt instanceof Date) return d.updatedAt.getTime()
-    const t = new Date(d.updatedAt).getTime()
-    return Number.isFinite(t) ? t : 0
-  }
-
-  const latestByOpenid = new Map()
-
-  // Exclude accounts that haven't synced in 90+ days to bound the scan.
-  // Docs without an updatedAt field (pre-fix legacy) are included as well.
-  const ninetyDaysAgo = new Date(Date.now() - 90 * 24 * 60 * 60 * 1000)
-
-  while (true) {
-    const res = await db.collection(COLLECTION)
-      .where(_.or([
-        { updatedAt: _.gte(ninetyDaysAgo) },
-        { updatedAt: _.exists(false) }
-      ]))
-      .skip(skip)
-      .limit(PAGE_SIZE)
-      .get()
-    if (!res.data || res.data.length === 0) break
-
-    for (const doc of res.data) {
-      const openid = doc._openid || 'unknown'
-      const current = latestByOpenid.get(openid)
-      if (!current || tsOf(doc) > tsOf(current)) {
-        latestByOpenid.set(openid, doc)
-      }
-    }
-
-    if (res.data.length < PAGE_SIZE) break
-    skip += PAGE_SIZE
-  }
+  // Latest doc per openid (cached + cursor-paginated in _fetchLatestByOpenid).
+  // Dedup rationale: a user may have multiple docs from the pre-fix cold-
+  // start add() bug; only the latest updatedAt counts, else we'd sum the
+  // same records N times and inflate the board. Latest (not first) also
+  // gives the freshest profile.nickname before admin-dedupe runs.
+  const latestByOpenid = await _fetchLatestByOpenid()
 
   // Second pass: each openid appears exactly once, so the accumulation
   // logic doesn't need any dedup guards.

utils/storage.js

@@ -9,6 +9,17 @@ const PROFILE_KEY = 'user_profile'
 
 let _idSeq = 0
 
+/**
+ * Record the timestamp of the last local mutation to single-value fields
+ * (settings / profile / customPlans / theme). _restoreFromCloud compares
+ * this against the cloud doc's updatedAt: if local changed after the cloud
+ * snapshot, we keep local to avoid clobbering unsynced edits. Records are
+ * exempt - they go through mergeRecords() which never loses data.
+ */
+const _markLocalChanged = () => {
+  try { wx.setStorageSync('_local_changed_at', Date.now()) } catch (e) {}
+}
+
 /**
  * Backfill an `id` for any record that doesn't have one.
  * Older records (e.g. data restored from cloud or migrated from a build
@@ -90,6 +101,49 @@ const deleteRecord = (recordId) => {
   cloud.pushAll()
 }
 
+/**
+ * Merge cloud records into local records WITHOUT losing either side.
+ *
+ * Why this exists: _restoreFromCloud used to overwrite training_records
+ * with the cloud doc verbatim. If the user finished a training during the
+ * async pullAll on launch, saveRecord had already written locally, and the
+ * subsequent restore wiped that fresh record with the cloud's older
+ * snapshot. Same hazard for multi-device edits.
+ *
+ * Dedup: records with a real (non-legacy) id dedup by id; legacy/idless
+ * records dedup by `date|duration` so old migrated data doesn't double up.
+ * Result is re-bucketed by month and sorted newest-first.
+ */
+const mergeRecords = (cloudRecords) => {
+  const local = wx.getStorageSync(RECORDS_KEY) || {}
+  const cloud = (cloudRecords && typeof cloudRecords === 'object') ? cloudRecords : {}
+  const seen = new Set()
+  const out = []
+  const push = (r) => {
+    if (!r) return
+    const id = r.id
+    const isRealId = id != null && id !== '' && !String(id).startsWith('legacy-')
+    const key = isRealId ? `id:${id}` : `c:${r.date}|${r.duration}`
+    if (seen.has(key)) return
+    seen.add(key)
+    out.push(r)
+  }
+  Object.keys(local).forEach((m) => (local[m] || []).forEach(push))
+  Object.keys(cloud).forEach((m) => (cloud[m] || []).forEach(push))
+
+  const merged = {}
+  out.forEach((r) => {
+    const mo = (r.date && r.date.substring) ? r.date.substring(0, 7) : 'unknown'
+    if (!merged[mo]) merged[mo] = []
+    merged[mo].push(r)
+  })
+  Object.keys(merged).forEach((mo) => {
+    merged[mo].sort((a, b) => (b.date || '').localeCompare(a.date || ''))
+  })
+  _ensureRecordIds(merged)
+  return merged
+}
+
 const getRecordsByMonth = (month) => {
   const records = getRecords()
   return records[month] || []
@@ -118,6 +172,7 @@ const getSettings = () => wx.getStorageSync(SETTINGS_KEY) || {
 
 const saveSettings = (settings) => {
   wx.setStorageSync(SETTINGS_KEY, settings)
+  _markLocalChanged()
   cloud.pushAll()
 }
 
@@ -145,6 +200,7 @@ const saveProfile = (profile) => {
     clean.avatarUrl = profile.avatarUrl
   }
   wx.setStorageSync(PROFILE_KEY, clean)
+  _markLocalChanged()
   cloud.pushAll()
   return clean
 }
@@ -170,6 +226,7 @@ const saveCustomPlan = (planId, planData) => {
   const plans = getCustomPlans()
   plans[planId] = planData
   wx.setStorageSync(CUSTOM_PLANS_KEY, plans)
+  _markLocalChanged()
   cloud.pushAll()
 }
 
@@ -179,6 +236,7 @@ const resetCustomPlan = (planId) => {
   if (!(planId in plans)) return
   delete plans[planId]
   wx.setStorageSync(CUSTOM_PLANS_KEY, plans)
+  _markLocalChanged()
   cloud.pushAll()
 }
 
@@ -252,6 +310,41 @@ const validateStreak = () => {
   return streak
 }
 
+/**
+ * Fully recompute the streak from actual training records. Used after a
+ * cloud restore/merge: the cloud doc's streak may be stale or belong to
+ * another device, so we trust the merged records over the cloud value.
+ */
+const recomputeStreak = () => {
+  const records = getRecords()
+  const allDates = new Set()
+  Object.values(records).forEach((monthRecs) => {
+    monthRecs.forEach((r) => allDates.add(dateOnly(r.date)))
+  })
+  const sorted = Array.from(allDates).sort().reverse()
+  if (sorted.length === 0) {
+    const empty = { count: 0, lastDate: '' }
+    wx.setStorageSync(STREAK_KEY, empty)
+    return empty
+  }
+  let count = 1
+  let prev = sorted[0]
+  for (let i = 1; i < sorted.length; i++) {
+    const prevDate = new Date(prev.replace(/-/g, '/'))
+    const curDate = new Date(sorted[i].replace(/-/g, '/'))
+    const diff = Math.round((prevDate - curDate) / (1000 * 60 * 60 * 24))
+    if (diff === 1) {
+      count++
+      prev = sorted[i]
+    } else {
+      break
+    }
+  }
+  const streak = { count, lastDate: sorted[0] }
+  wx.setStorageSync(STREAK_KEY, streak)
+  return streak
+}
+
 const updateStreak = (date) => {
   const streak = getStreak()
   const todayFull = date || getToday()
@@ -310,6 +403,7 @@ module.exports = {
   getRecords,
   saveRecord,
   deleteRecord,
+  mergeRecords,
   getRecordsByMonth,
   getTotalStats,
   getSettings,
@@ -321,6 +415,7 @@ module.exports = {
   saveProfile,
   getStreak,
   validateStreak,
+  recomputeStreak,
   updateStreak,
   getToday,
   getDateOffset,