perf(mileage): stream workbook export rows

vehicle-data-platform/apps/web/src/v2/pages/StatisticsPage.tsx

@@ -4,7 +4,7 @@ import { FormEvent, useEffect, useMemo, useRef, useState } from 'react';
 import { useSearchParams } from 'react-router-dom';
 import { api } from '../../api/client';
 import type { DailyMileageRow, MileageStatistics, Page, VehicleRow } from '../../api/types';
-import { downloadMileageWorkbook } from '../domain/mileageExport';
+import { createMileageExportStream, type MileageExportStream } from '../domain/mileageExport';
 import { formatZhNumber } from '../domain/formatters';
 import { InlineError } from '../shared/AsyncState';
 import { QUERY_MEMORY, retainPreviousPageWithinScope } from '../queryPolicy';
@@ -347,6 +347,7 @@ export default function StatisticsPage() {
     };
     setIsExporting(true);
     setExportFeedback('');
+    let exportStream: MileageExportStream | undefined;
     try {
       let vehicles: VehicleOption[] = criteria.vehicles.map((vehicle) => ({ ...vehicle }));
       if (!vehicles.length) {
@@ -362,7 +363,14 @@ export default function StatisticsPage() {
           if (offset >= result.total) break;
         }
       }
-      const mileageRows: DailyMileageRow[] = [];
+      const plateByVin = new Map(vehicles.filter((vehicle) => vehicle.plate).map((vehicle) => [vehicle.vin, vehicle.plate]));
+      exportStream = createMileageExportStream({
+        dateFrom: criteria.dateFrom,
+        dateTo: criteria.dateTo,
+        dates,
+        sources: criteria.sources.filter((source) => source.enabled),
+        exportedAt: new Date()
+      }, controller.signal);
       const vehicleBatches = criteria.vehicles.length
         ? Array.from({ length: Math.ceil(vehicles.length / EXPORT_VIN_BATCH_SIZE) }, (_, index) => vehicles.slice(index * EXPORT_VIN_BATCH_SIZE, (index + 1) * EXPORT_VIN_BATCH_SIZE))
         : [[] as VehicleOption[]];
@@ -375,24 +383,17 @@ export default function StatisticsPage() {
         while (true) {
           const params = mileageParams({ ...criteria, vehicles: vehicleBatch }, offset);
           const result = await api.dailyMileage(params, controller.signal);
-          mileageRows.push(...result.items);
+          for (const row of result.items) if (row.plate) plateByVin.set(row.vin, row.plate);
+          exportStream.appendRows(result.items);
           offset += result.items.length;
           reportProgress({ label: mileageLabel, completed: offset, total: result.total });
           if (!result.items.length || offset >= result.total) break;
         }
       }
-      const plateByVin = new Map(mileageRows.filter((row) => row.plate).map((row) => [row.vin, row.plate]));
       vehicles = vehicles.map((vehicle) => ({ ...vehicle, plate: vehicle.plate || plateByVin.get(vehicle.vin) || '' }));
       reportProgress({ label: '正在后台生成 Excel 文件' });
-      await downloadMileageWorkbook({
-        dateFrom: criteria.dateFrom,
-        dateTo: criteria.dateTo,
-        dates,
-        vehicles,
-        mileageRows,
-        sources: criteria.sources.filter((source) => source.enabled),
-        exportedAt: new Date()
-      }, controller.signal);
+      await exportStream.finish(vehicles);
+      exportStream = undefined;
       if (mountedRef.current) setExportFeedback(`已导出 ${vehicles.length} 辆车`);
     } catch (error) {
       if (mountedRef.current) {
@@ -401,6 +402,7 @@ export default function StatisticsPage() {
           : error instanceof Error ? `导出失败：${error.message}` : '导出失败，请稍后重试');
       }
     } finally {
+      exportStream?.dispose();
       if (exportControllerRef.current === controller) exportControllerRef.current = null;
       if (mountedRef.current) {
         setIsExporting(false);