优化选择

src/components/Export/ExportDateRangeDialog.scss

@@ -212,6 +212,11 @@
     display: inline-flex;
     align-items: center;
     justify-content: center;
+
+    &:disabled {
+      cursor: not-allowed;
+      opacity: 0.45;
+    }
   }
 }
 
@@ -251,11 +256,23 @@
     transform: translateY(-1px);
   }
 
+  &:disabled:hover {
+    border-color: transparent;
+    transform: none;
+  }
+
   &.outside {
     color: var(--text-quaternary);
     opacity: 0.72;
   }
 
+  &.disabled {
+    cursor: not-allowed;
+    opacity: 0.35;
+    transform: none;
+    border-color: transparent;
+  }
+
   &.in-range {
     background: rgba(var(--primary-rgb), 0.1);
     color: var(--primary);

src/components/Export/ExportDateRangeDialog.tsx

@@ -25,6 +25,8 @@ interface ExportDateRangeDialogProps {
   open: boolean
   value: ExportDateRangeSelection
   title?: string
+  minDate?: Date | null
+  maxDate?: Date | null
   onClose: () => void
   onConfirm: (value: ExportDateRangeSelection) => void
 }
@@ -35,19 +37,65 @@ interface ExportDateRangeDialogDraft extends ExportDateRangeSelection {
   panelMonth: Date
 }
 
-const buildDialogDraft = (value: ExportDateRangeSelection): ExportDateRangeDialogDraft => ({
+const resolveBounds = (minDate?: Date | null, maxDate?: Date | null): { minDate: Date; maxDate: Date } | null => {
-  ...cloneExportDateRangeSelection(value),
+  if (!(minDate instanceof Date) || Number.isNaN(minDate.getTime())) return null
-  panelMonth: toMonthStart(value.dateRange.start)
+  if (!(maxDate instanceof Date) || Number.isNaN(maxDate.getTime())) return null
-})
+  const normalizedMin = startOfDay(minDate)
+  const normalizedMax = endOfDay(maxDate)
+  if (normalizedMin.getTime() > normalizedMax.getTime()) return null
+  return {
+    minDate: normalizedMin,
+    maxDate: normalizedMax
+  }
+}
+
+const clampSelectionToBounds = (
+  value: ExportDateRangeSelection,
+  minDate?: Date | null,
+  maxDate?: Date | null
+): ExportDateRangeSelection => {
+  const bounds = resolveBounds(minDate, maxDate)
+  if (!bounds) return cloneExportDateRangeSelection(value)
+
+  const rawStart = value.useAllTime ? bounds.minDate : startOfDay(value.dateRange.start)
+  const rawEnd = value.useAllTime ? bounds.maxDate : endOfDay(value.dateRange.end)
+  const nextStart = new Date(Math.min(Math.max(rawStart.getTime(), bounds.minDate.getTime()), bounds.maxDate.getTime()))
+  const nextEndCandidate = new Date(Math.min(Math.max(rawEnd.getTime(), bounds.minDate.getTime()), bounds.maxDate.getTime()))
+  const nextEnd = nextEndCandidate.getTime() < nextStart.getTime() ? endOfDay(nextStart) : nextEndCandidate
+  const changed = nextStart.getTime() !== rawStart.getTime() || nextEnd.getTime() !== rawEnd.getTime()
+
+  return {
+    preset: value.useAllTime ? value.preset : (changed ? 'custom' : value.preset),
+    useAllTime: value.useAllTime,
+    dateRange: {
+      start: nextStart,
+      end: nextEnd
+    }
+  }
+}
+
+const buildDialogDraft = (
+  value: ExportDateRangeSelection,
+  minDate?: Date | null,
+  maxDate?: Date | null
+): ExportDateRangeDialogDraft => {
+  const nextValue = clampSelectionToBounds(value, minDate, maxDate)
+  return {
+    ...nextValue,
+    panelMonth: toMonthStart(nextValue.dateRange.start)
+  }
+}
 
 export function ExportDateRangeDialog({
   open,
   value,
   title = '时间范围设置',
+  minDate,
+  maxDate,
   onClose,
   onConfirm
 }: ExportDateRangeDialogProps) {
-  const [draft, setDraft] = useState<ExportDateRangeDialogDraft>(() => buildDialogDraft(value))
+  const [draft, setDraft] = useState<ExportDateRangeDialogDraft>(() => buildDialogDraft(value, minDate, maxDate))
   const [activeBoundary, setActiveBoundary] = useState<ActiveBoundary>('start')
   const [dateInput, setDateInput] = useState({
     start: formatDateInputValue(value.dateRange.start),
@@ -57,7 +105,7 @@ export function ExportDateRangeDialog({
 
   useEffect(() => {
     if (!open) return
-    const nextDraft = buildDialogDraft(value)
+    const nextDraft = buildDialogDraft(value, minDate, maxDate)
     setDraft(nextDraft)
     setActiveBoundary('start')
     setDateInput({
@@ -65,7 +113,7 @@ export function ExportDateRangeDialog({
       end: formatDateInputValue(nextDraft.dateRange.end)
     })
     setDateInputError({ start: false, end: false })
-  }, [open, value])
+  }, [maxDate, minDate, open, value])
 
   useEffect(() => {
     if (!open) return
@@ -76,8 +124,24 @@ export function ExportDateRangeDialog({
     setDateInputError({ start: false, end: false })
   }, [draft.dateRange.end.getTime(), draft.dateRange.start.getTime(), open])
 
-  const setRangeStart = useCallback((targetDate: Date) => {
+  const bounds = useMemo(() => resolveBounds(minDate, maxDate), [maxDate, minDate])
+  const clampStartDate = useCallback((targetDate: Date) => {
     const start = startOfDay(targetDate)
+    if (!bounds) return start
+    if (start.getTime() < bounds.minDate.getTime()) return bounds.minDate
+    if (start.getTime() > bounds.maxDate.getTime()) return startOfDay(bounds.maxDate)
+    return start
+  }, [bounds])
+  const clampEndDate = useCallback((targetDate: Date) => {
+    const end = endOfDay(targetDate)
+    if (!bounds) return end
+    if (end.getTime() < bounds.minDate.getTime()) return endOfDay(bounds.minDate)
+    if (end.getTime() > bounds.maxDate.getTime()) return bounds.maxDate
+    return end
+  }, [bounds])
+
+  const setRangeStart = useCallback((targetDate: Date) => {
+    const start = clampStartDate(targetDate)
     setDraft(prev => {
       const nextEnd = prev.dateRange.end < start ? endOfDay(start) : prev.dateRange.end
       return {
@@ -91,12 +155,12 @@ export function ExportDateRangeDialog({
         panelMonth: toMonthStart(start)
       }
     })
-  }, [])
+  }, [clampStartDate])
 
   const setRangeEnd = useCallback((targetDate: Date) => {
-    const end = endOfDay(targetDate)
+    const end = clampEndDate(targetDate)
     setDraft(prev => {
-      const nextStart = prev.useAllTime ? startOfDay(targetDate) : prev.dateRange.start
+      const nextStart = prev.useAllTime ? clampStartDate(targetDate) : prev.dateRange.start
       const nextEnd = end < nextStart ? endOfDay(nextStart) : end
       return {
         ...prev,
@@ -109,11 +173,13 @@ export function ExportDateRangeDialog({
         panelMonth: toMonthStart(targetDate)
       }
     })
-  }, [])
+  }, [clampEndDate, clampStartDate])
 
   const applyPreset = useCallback((preset: Exclude<ExportDateRangePreset, 'custom'>) => {
     if (preset === 'all') {
-      const previewRange = createDefaultDateRange()
+      const previewRange = bounds
+        ? { start: bounds.minDate, end: bounds.maxDate }
+        : createDefaultDateRange()
       setDraft(prev => ({
         ...prev,
         preset,
@@ -125,7 +191,11 @@ export function ExportDateRangeDialog({
       return
     }
 
-    const range = createDateRangeByPreset(preset)
+    const range = clampSelectionToBounds({
+      preset,
+      useAllTime: false,
+      dateRange: createDateRangeByPreset(preset)
+    }, minDate, maxDate).dateRange
     setDraft(prev => ({
       ...prev,
       preset,
@@ -134,7 +204,7 @@ export function ExportDateRangeDialog({
       panelMonth: toMonthStart(range.start)
     }))
     setActiveBoundary('start')
-  }, [])
+  }, [bounds, maxDate, minDate])
 
   const commitStartFromInput = useCallback(() => {
     const parsed = parseDateInputValue(dateInput.start)
@@ -200,6 +270,10 @@ export function ExportDateRangeDialog({
   }, [draft])
 
   const calendarCells = useMemo(() => buildCalendarCells(draft.panelMonth), [draft.panelMonth])
+  const minPanelMonth = bounds ? toMonthStart(bounds.minDate) : null
+  const maxPanelMonth = bounds ? toMonthStart(bounds.maxDate) : null
+  const canShiftPrev = !minPanelMonth || draft.panelMonth.getTime() > minPanelMonth.getTime()
+  const canShiftNext = !maxPanelMonth || draft.panelMonth.getTime() < maxPanelMonth.getTime()
 
   const isStartSelected = useCallback((date: Date) => (
     !draft.useAllTime && isSameDay(date, draft.dateRange.start)
@@ -215,6 +289,12 @@ export function ExportDateRangeDialog({
     startOfDay(date).getTime() <= startOfDay(draft.dateRange.end).getTime()
   ), [draft])
 
+  const isDateSelectable = useCallback((date: Date) => {
+    if (!bounds) return true
+    const target = startOfDay(date).getTime()
+    return target >= startOfDay(bounds.minDate).getTime() && target <= startOfDay(bounds.maxDate).getTime()
+  }, [bounds])
+
   const hintText = draft.useAllTime
     ? '选择开始或结束日期后，会自动切换为自定义时间范围'
     : (activeBoundary === 'start' ? '下一次点击将设置开始日期' : '下一次点击将设置结束日期')
@@ -323,10 +403,10 @@ export function ExportDateRangeDialog({
               <strong>{formatCalendarMonthTitle(draft.panelMonth)}</strong>
             </div>
             <div className="export-date-range-calendar-nav">
-              <button type="button" onClick={() => shiftPanelMonth(-1)} aria-label="上个月">
+              <button type="button" onClick={() => shiftPanelMonth(-1)} aria-label="上个月" disabled={!canShiftPrev}>
                 <ChevronLeft size={14} />
               </button>
-              <button type="button" onClick={() => shiftPanelMonth(1)} aria-label="下个月">
+              <button type="button" onClick={() => shiftPanelMonth(1)} aria-label="下个月" disabled={!canShiftNext}>
                 <ChevronRight size={14} />
               </button>
             </div>
@@ -341,13 +421,16 @@ export function ExportDateRangeDialog({
               const startSelected = isStartSelected(cell.date)
               const endSelected = isEndSelected(cell.date)
               const inRange = isDateInRange(cell.date)
+              const selectable = isDateSelectable(cell.date)
               return (
                 <button
                   key={cell.date.getTime()}
                   type="button"
+                  disabled={!selectable}
                   className={[
                     'export-date-range-calendar-day',
                     cell.inCurrentMonth ? '' : 'outside',
+                    selectable ? '' : 'disabled',
                     inRange ? 'in-range' : '',
                     startSelected ? 'range-start' : '',
                     endSelected ? 'range-end' : '',

src/pages/ExportPage.tsx

@@ -52,10 +52,13 @@ import { ExportDefaultsSettingsForm, type ExportDefaultsSettingsPatch } from '..
 import type { SnsPost } from '../types/sns'
 import {
   cloneExportDateRange,
+  cloneExportDateRangeSelection,
   createDefaultDateRange,
   createDefaultExportDateRangeSelection,
   getExportDateRangeLabel,
   resolveExportDateRangeConfig,
+  startOfDay,
+  endOfDay,
   type ExportDateRangeSelection
 } from '../utils/exportDateRange'
 import './ExportPage.scss'
@@ -830,6 +833,13 @@ interface SessionContentMetric {
   transferMessages?: number
   redPacketMessages?: number
   callMessages?: number
+  firstTimestamp?: number
+  lastTimestamp?: number
+}
+
+interface TimeRangeBounds {
+  minDate: Date
+  maxDate: Date
 }
 
 interface SessionExportCacheMeta {
@@ -1049,27 +1059,74 @@ const normalizeMessageCount = (value: unknown): number | undefined => {
   return Math.floor(parsed)
 }
 
+const normalizeTimestampSeconds = (value: unknown): number | undefined => {
+  const parsed = Number(value)
+  if (!Number.isFinite(parsed) || parsed <= 0) return undefined
+  return Math.floor(parsed)
+}
+
+const clampExportSelectionToBounds = (
+  selection: ExportDateRangeSelection,
+  bounds: TimeRangeBounds | null
+): ExportDateRangeSelection => {
+  if (!bounds) return cloneExportDateRangeSelection(selection)
+
+  const boundedStart = startOfDay(bounds.minDate)
+  const boundedEnd = endOfDay(bounds.maxDate)
+  const originalStart = selection.useAllTime ? boundedStart : startOfDay(selection.dateRange.start)
+  const originalEnd = selection.useAllTime ? boundedEnd : endOfDay(selection.dateRange.end)
+  const nextStart = new Date(Math.min(Math.max(originalStart.getTime(), boundedStart.getTime()), boundedEnd.getTime()))
+  const nextEndCandidate = new Date(Math.min(Math.max(originalEnd.getTime(), boundedStart.getTime()), boundedEnd.getTime()))
+  const nextEnd = nextEndCandidate.getTime() < nextStart.getTime() ? endOfDay(nextStart) : nextEndCandidate
+  const rangeChanged = nextStart.getTime() !== originalStart.getTime() || nextEnd.getTime() !== originalEnd.getTime()
+
+  return {
+    preset: selection.useAllTime ? selection.preset : (rangeChanged ? 'custom' : selection.preset),
+    useAllTime: selection.useAllTime,
+    dateRange: {
+      start: nextStart,
+      end: nextEnd
+    }
+  }
+}
+
+const areExportSelectionsEqual = (left: ExportDateRangeSelection, right: ExportDateRangeSelection): boolean => (
+  left.preset === right.preset &&
+  left.useAllTime === right.useAllTime &&
+  left.dateRange.start.getTime() === right.dateRange.start.getTime() &&
+  left.dateRange.end.getTime() === right.dateRange.end.getTime()
+)
+
 const pickSessionMediaMetric = (
   metricRaw: SessionExportMetric | SessionContentMetric | undefined
 ): SessionContentMetric | null => {
   if (!metricRaw) return null
+  const totalMessages = normalizeMessageCount(metricRaw.totalMessages)
   const voiceMessages = normalizeMessageCount(metricRaw.voiceMessages)
   const imageMessages = normalizeMessageCount(metricRaw.imageMessages)
   const videoMessages = normalizeMessageCount(metricRaw.videoMessages)
   const emojiMessages = normalizeMessageCount(metricRaw.emojiMessages)
+  const firstTimestamp = normalizeTimestampSeconds(metricRaw.firstTimestamp)
+  const lastTimestamp = normalizeTimestampSeconds(metricRaw.lastTimestamp)
   if (
+    typeof totalMessages !== 'number' &&
     typeof voiceMessages !== 'number' &&
     typeof imageMessages !== 'number' &&
     typeof videoMessages !== 'number' &&
-    typeof emojiMessages !== 'number'
+    typeof emojiMessages !== 'number' &&
+    typeof firstTimestamp !== 'number' &&
+    typeof lastTimestamp !== 'number'
   ) {
     return null
   }
   return {
+    totalMessages,
     voiceMessages,
     imageMessages,
     videoMessages,
-    emojiMessages
+    emojiMessages,
+    firstTimestamp,
+    lastTimestamp
   }
 }
 
@@ -1520,6 +1577,8 @@ function ExportPage() {
   const [snsExportLivePhotos, setSnsExportLivePhotos] = useState(false)
   const [snsExportVideos, setSnsExportVideos] = useState(false)
   const [isTimeRangeDialogOpen, setIsTimeRangeDialogOpen] = useState(false)
+  const [isResolvingTimeRangeBounds, setIsResolvingTimeRangeBounds] = useState(false)
+  const [timeRangeBounds, setTimeRangeBounds] = useState<TimeRangeBounds | null>(null)
   const [isExportDefaultsModalOpen, setIsExportDefaultsModalOpen] = useState(false)
   const [timeRangeSelection, setTimeRangeSelection] = useState<ExportDateRangeSelection>(() => createDefaultExportDateRangeSelection())
   const [exportDefaultFormat, setExportDefaultFormat] = useState<TextExportFormat>('excel')
@@ -2686,7 +2745,9 @@ function ExportPage() {
         typeof emojiMessages !== 'number' &&
         typeof transferMessages !== 'number' &&
         typeof redPacketMessages !== 'number' &&
-        typeof callMessages !== 'number'
+        typeof callMessages !== 'number' &&
+        typeof normalizeTimestampSeconds(metricRaw.firstTimestamp) !== 'number' &&
+        typeof normalizeTimestampSeconds(metricRaw.lastTimestamp) !== 'number'
       ) {
         continue
       }
@@ -2699,7 +2760,9 @@ function ExportPage() {
         emojiMessages,
         transferMessages,
         redPacketMessages,
-        callMessages
+        callMessages,
+        firstTimestamp: normalizeTimestampSeconds(metricRaw.firstTimestamp),
+        lastTimestamp: normalizeTimestampSeconds(metricRaw.lastTimestamp)
       }
       if (typeof totalMessages === 'number') {
         nextMessageCounts[sessionId] = totalMessages
@@ -2743,7 +2806,9 @@ function ExportPage() {
             previous.emojiMessages === nextMetric.emojiMessages &&
             previous.transferMessages === nextMetric.transferMessages &&
             previous.redPacketMessages === nextMetric.redPacketMessages &&
-            previous.callMessages === nextMetric.callMessages
+            previous.callMessages === nextMetric.callMessages &&
+            previous.firstTimestamp === nextMetric.firstTimestamp &&
+            previous.lastTimestamp === nextMetric.lastTimestamp
           ) {
             continue
           }
@@ -3898,6 +3963,7 @@ function ExportPage() {
   const openExportDialog = useCallback((payload: Omit<ExportDialogState, 'open'>) => {
     setExportDialog({ open: true, ...payload })
     setIsTimeRangeDialogOpen(false)
+    setTimeRangeBounds(null)
     setTimeRangeSelection(exportDefaultDateRangeSelection)
 
     setOptions(prev => {
@@ -3960,11 +4026,108 @@ function ExportPage() {
   const closeExportDialog = useCallback(() => {
     setExportDialog(prev => ({ ...prev, open: false }))
     setIsTimeRangeDialogOpen(false)
+    setTimeRangeBounds(null)
   }, [])
 
+  const resolveChatExportTimeRangeBounds = useCallback(async (sessionIds: string[]): Promise<TimeRangeBounds | null> => {
+    const normalizedSessionIds = Array.from(new Set((sessionIds || []).map(id => String(id || '').trim()).filter(Boolean)))
+    if (normalizedSessionIds.length === 0) return null
+
+    let minTimestamp: number | undefined
+    let maxTimestamp: number | undefined
+    const resolvedSessionIds = new Set<string>()
+
+    const absorbMetric = (sessionId: string, metric?: { firstTimestamp?: number; lastTimestamp?: number } | null) => {
+      if (!metric) return
+      const firstTimestamp = normalizeTimestampSeconds(metric.firstTimestamp)
+      const lastTimestamp = normalizeTimestampSeconds(metric.lastTimestamp)
+      if (typeof firstTimestamp !== 'number' || typeof lastTimestamp !== 'number') return
+      resolvedSessionIds.add(sessionId)
+      if (minTimestamp === undefined || firstTimestamp < minTimestamp) minTimestamp = firstTimestamp
+      if (maxTimestamp === undefined || lastTimestamp > maxTimestamp) maxTimestamp = lastTimestamp
+    }
+
+    for (const sessionId of normalizedSessionIds) {
+      absorbMetric(sessionId, sessionContentMetrics[sessionId])
+      if (sessionDetail?.wxid === sessionId) {
+        absorbMetric(sessionId, {
+          firstTimestamp: sessionDetail.firstMessageTime,
+          lastTimestamp: sessionDetail.latestMessageTime
+        })
+      }
+    }
+
+    const applyStatsResult = (result?: {
+      success: boolean
+      data?: Record<string, SessionExportMetric>
+    } | null) => {
+      if (!result?.success || !result.data) return
+      applySessionMediaMetricsFromStats(result.data)
+      for (const sessionId of normalizedSessionIds) {
+        absorbMetric(sessionId, result.data[sessionId])
+      }
+    }
+
+    const missingSessionIds = () => normalizedSessionIds.filter(sessionId => !resolvedSessionIds.has(sessionId))
+
+    if (missingSessionIds().length > 0) {
+      applyStatsResult(await window.electronAPI.chat.getExportSessionStats(
+        missingSessionIds(),
+        { includeRelations: false, allowStaleCache: true, cacheOnly: true }
+      ))
+    }
+
+    if (missingSessionIds().length > 0) {
+      applyStatsResult(await window.electronAPI.chat.getExportSessionStats(
+        missingSessionIds(),
+        { includeRelations: false, allowStaleCache: true }
+      ))
+    }
+
+    if (resolvedSessionIds.size !== normalizedSessionIds.length) {
+      return null
+    }
+    if (typeof minTimestamp !== 'number' || typeof maxTimestamp !== 'number') {
+      return null
+    }
+
+    return {
+      minDate: new Date(minTimestamp * 1000),
+      maxDate: new Date(maxTimestamp * 1000)
+    }
+  }, [applySessionMediaMetricsFromStats, sessionContentMetrics, sessionDetail])
+
   const openTimeRangeDialog = useCallback(() => {
+    void (async () => {
+      if (isResolvingTimeRangeBounds) return
+      setIsResolvingTimeRangeBounds(true)
+      try {
+        let nextBounds: TimeRangeBounds | null = null
+        if (exportDialog.scope !== 'sns') {
+          nextBounds = await resolveChatExportTimeRangeBounds(exportDialog.sessionIds)
+        }
+        setTimeRangeBounds(nextBounds)
+        if (nextBounds) {
+          const nextSelection = clampExportSelectionToBounds(timeRangeSelection, nextBounds)
+          if (!areExportSelectionsEqual(nextSelection, timeRangeSelection)) {
+            setTimeRangeSelection(nextSelection)
+            setOptions(prev => ({
+              ...prev,
+              useAllTime: nextSelection.useAllTime,
+              dateRange: cloneExportDateRange(nextSelection.dateRange)
+            }))
+          }
+        }
         setIsTimeRangeDialogOpen(true)
-  }, [])
+      } catch (error) {
+        console.error('导出页解析时间范围边界失败', error)
+        setTimeRangeBounds(null)
+        setIsTimeRangeDialogOpen(true)
+      } finally {
+        setIsResolvingTimeRangeBounds(false)
+      }
+    })()
+  }, [exportDialog.scope, exportDialog.sessionIds, isResolvingTimeRangeBounds, resolveChatExportTimeRangeBounds, timeRangeSelection])
 
   const closeTimeRangeDialog = useCallback(() => {
     setIsTimeRangeDialogOpen(false)
@@ -7753,8 +7916,9 @@ function ExportPage() {
                     type="button"
                     className="time-range-trigger"
                     onClick={openTimeRangeDialog}
+                    disabled={isResolvingTimeRangeBounds}
                   >
-                    <span>{timeRangeSummaryLabel}</span>
+                    <span>{isResolvingTimeRangeBounds ? '正在统计可选时间...' : timeRangeSummaryLabel}</span>
                     <span className="time-range-arrow">&gt;</span>
                   </button>
                 </div>
@@ -7840,6 +8004,8 @@ function ExportPage() {
             <ExportDateRangeDialog
               open={isTimeRangeDialogOpen}
               value={timeRangeSelection}
+              minDate={timeRangeBounds?.minDate}
+              maxDate={timeRangeBounds?.maxDate}
               onClose={closeTimeRangeDialog}
               onConfirm={(nextSelection) => {
                 setTimeRangeSelection(nextSelection)

src/services/config.ts

@@ -580,6 +580,8 @@ export interface ExportSessionContentMetricCacheEntry {
   imageMessages?: number
   videoMessages?: number
   emojiMessages?: number
+  firstTimestamp?: number
+  lastTimestamp?: number
 }
 
 export interface ExportSessionContentMetricCacheItem {
@@ -742,6 +744,12 @@ export async function getExportSessionContentMetricCache(scopeKey: string): Prom
     if (typeof source.emojiMessages === 'number' && Number.isFinite(source.emojiMessages) && source.emojiMessages >= 0) {
       metric.emojiMessages = Math.floor(source.emojiMessages)
     }
+    if (typeof source.firstTimestamp === 'number' && Number.isFinite(source.firstTimestamp) && source.firstTimestamp > 0) {
+      metric.firstTimestamp = Math.floor(source.firstTimestamp)
+    }
+    if (typeof source.lastTimestamp === 'number' && Number.isFinite(source.lastTimestamp) && source.lastTimestamp > 0) {
+      metric.lastTimestamp = Math.floor(source.lastTimestamp)
+    }
     if (Object.keys(metric).length === 0) continue
     metrics[sessionId] = metric
   }
@@ -781,6 +789,12 @@ export async function setExportSessionContentMetricCache(
     if (typeof rawMetric.emojiMessages === 'number' && Number.isFinite(rawMetric.emojiMessages) && rawMetric.emojiMessages >= 0) {
       metric.emojiMessages = Math.floor(rawMetric.emojiMessages)
     }
+    if (typeof rawMetric.firstTimestamp === 'number' && Number.isFinite(rawMetric.firstTimestamp) && rawMetric.firstTimestamp > 0) {
+      metric.firstTimestamp = Math.floor(rawMetric.firstTimestamp)
+    }
+    if (typeof rawMetric.lastTimestamp === 'number' && Number.isFinite(rawMetric.lastTimestamp) && rawMetric.lastTimestamp > 0) {
+      metric.lastTimestamp = Math.floor(rawMetric.lastTimestamp)
+    }
     if (Object.keys(metric).length === 0) continue
     normalized[sessionId] = metric
   }