feat(admin-web): 批量下载改为逐个下载到用户选择的目录

- 先弹出目录选择对话框让用户指定保存位置
- 逐个下载合同 PDF 到指定目录
- 显示下载进度（已下载数/总数）

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

frontend/admin-web/src/app/(dashboard)/contracts/page.tsx

@@ -141,8 +141,6 @@ export default function ContractsPage() {
 
   // 批量下载状态
   const [batchDownloading, setBatchDownloading] = useState(false);
-  const [batchProgress, setBatchProgress] = useState(0);
-  const [downloadStage, setDownloadStage] = useState<'idle' | 'packaging' | 'downloading'>('idle');
   const [downloadProgress, setDownloadProgress] = useState(0);
 
   // 轮询任务状态直到完成
@@ -151,7 +149,7 @@ export default function ContractsPage() {
     for (let i = 0; i < maxAttempts; i++) {
       try {
         const status = await contractService.getBatchDownloadStatus(taskNo);
-        setBatchProgress(status.progress);
+        // 打包进度（未使用）
 
         if (status.status === 'COMPLETED' && status.resultFileUrl) {
           return status.resultFileUrl;
@@ -169,124 +167,106 @@ export default function ContractsPage() {
     throw new Error('任务处理超时');
   };
 
-  // 使用 File System Access API 让用户选择保存位置（Chrome/Edge 支持）
+  // 下载进度详情
-  const saveFileWithPicker = async (url: string, suggestedName: string): Promise<boolean> => {
+  const [downloadedCount, setDownloadedCount] = useState(0);
-    try {
+  const [totalCount, setTotalCount] = useState(0);
-      // 检查浏览器是否支持 File System Access API
-      if ('showSaveFilePicker' in window) {
-        // 弹出保存对话框让用户选择位置（先选择再下载）
-        const fileHandle = await (window as unknown as { showSaveFilePicker: (options: unknown) => Promise<FileSystemFileHandle> }).showSaveFilePicker({
-          suggestedName,
-          types: [{
-            description: 'ZIP 压缩文件',
-            accept: { 'application/zip': ['.zip'] },
-          }],
-        });
 
-        // 用户选择了保存位置后，开始下载并显示进度
+  // 批量下载（先选择保存目录，再逐个下载合同）
-        setDownloadStage('downloading');
-        setDownloadProgress(0);
-
-        const response = await fetch(url);
-        const contentLength = response.headers.get('content-length');
-        const total = contentLength ? parseInt(contentLength, 10) : 0;
-
-        if (!response.body) {
-          throw new Error('无法读取响应流');
-        }
-
-        const reader = response.body.getReader();
-        const chunks: ArrayBuffer[] = [];
-        let loaded = 0;
-
-        while (true) {
-          const { done, value } = await reader.read();
-          if (done) break;
-
-          chunks.push(value.buffer as ArrayBuffer);
-          loaded += value.length;
-
-          if (total > 0) {
-            const progress = Math.round((loaded / total) * 100);
-            setDownloadProgress(progress);
-          }
-        }
-
-        // 合并所有 chunks 为 Blob
-        const blob = new Blob(chunks, { type: 'application/zip' });
-
-        // 写入文件
-        const writable = await fileHandle.createWritable();
-        await writable.write(blob);
-        await writable.close();
-
-        setDownloadProgress(100);
-        return true;
-      }
-    } catch (error) {
-      // 用户取消或浏览器不支持，回退到普通下载
-      console.log('File System Access API 不可用或用户取消，使用普通下载');
-    }
-    return false;
-  };
-
-  // 批量下载（创建下载任务并等待完成后自动下载）
   const handleBatchDownload = async () => {
+    // 检查浏览器是否支持选择目录
+    if (!('showDirectoryPicker' in window)) {
+      toast.error('当前浏览器不支持选择保存目录，请使用 Chrome 或 Edge 浏览器');
+      return;
+    }
+
+    // 第一步：让用户选择保存目录
+    let dirHandle: FileSystemDirectoryHandle;
+    try {
+      dirHandle = await (window as unknown as { showDirectoryPicker: () => Promise<FileSystemDirectoryHandle> }).showDirectoryPicker();
+    } catch (error: unknown) {
+      const err = error as Error;
+      if (err.name === 'AbortError') {
+        toast.info('已取消');
+      } else {
+        toast.error('选择保存目录失败');
+      }
+      return;
+    }
+
+    // 第二步：获取已签署的合同列表
     setBatchDownloading(true);
-    setBatchProgress(0);
-    setDownloadStage('packaging');
     setDownloadProgress(0);
+    setDownloadedCount(0);
+    setTotalCount(0);
 
     try {
-      toast.info('正在准备批量下载，请稍候...');
+      toast.info('正在获取合同列表...');
 
-      const result = await contractService.createBatchDownload({
+      // 获取所有已签署的合同
-        filters: {
+      const result = await contractService.getContracts({
-          signedAfter: filters.signedAfter || undefined,
+        signedAfter: filters.signedAfter || undefined,
-          signedBefore: filters.signedBefore || undefined,
+        signedBefore: filters.signedBefore || undefined,
-          provinceCode: filters.provinceCode || undefined,
+        provinceCode: filters.provinceCode || undefined,
-          cityCode: filters.cityCode || undefined,
+        cityCode: filters.cityCode || undefined,
-        },
+        status: 'SIGNED',
+        page: 1,
+        pageSize: 10000, // 获取所有
       });
 
-      // 轮询等待任务完成
+      const contracts = result.items.filter(c => c.signedPdfUrl);
-      const downloadUrl = await pollTaskUntilComplete(result.taskNo);
+      const total = contracts.length;
+      setTotalCount(total);
 
-      if (downloadUrl) {
+      if (total === 0) {
-        // 生成文件名
+        toast.warning('没有可下载的已签署合同');
-        const today = new Date().toISOString().split('T')[0].replace(/-/g, '');
+        return;
-        const suggestedName = `contracts_${today}.zip`;
-
-        // 优先使用 File System Access API 让用户选择保存位置
-        toast.info('请选择保存位置...');
-        const saved = await saveFileWithPicker(downloadUrl, suggestedName);
-
-        if (saved) {
-          toast.success('文件保存成功！');
-        } else {
-          // 浏览器不支持或用户取消，使用备用方法
-          const link = document.createElement('a');
-          link.href = downloadUrl;
-          link.download = suggestedName;
-          document.body.appendChild(link);
-          link.click();
-          document.body.removeChild(link);
-          toast.success('下载已开始');
-        }
-
-        // 保存当前时间作为最后下载时间
-        const now = new Date().toISOString();
-        localStorage.setItem('contract_last_download_time', now);
-        setLastDownloadTime(now);
       }
+
+      toast.info(`开始下载 ${total} 份合同...`);
+
+      // 第三步：逐个下载合同到用户选择的目录
+      let downloaded = 0;
+      for (const contract of contracts) {
+        try {
+          // 生成文件名
+          const fileName = `${contract.contractNo}_${contract.userRealName || '未实名'}_${contract.treeCount}棵.pdf`;
+
+          // 下载 PDF
+          const downloadUrl = contractService.getDownloadUrl(contract.orderNo);
+          const response = await fetch(downloadUrl);
+          if (!response.ok) {
+            console.error(`下载失败: ${contract.orderNo}`);
+            continue;
+          }
+
+          const blob = await response.blob();
+
+          // 保存到用户选择的目录
+          const fileHandle = await dirHandle.getFileHandle(fileName, { create: true });
+          const writable = await fileHandle.createWritable();
+          await writable.write(blob);
+          await writable.close();
+
+          downloaded++;
+          setDownloadedCount(downloaded);
+          setDownloadProgress(Math.round((downloaded / total) * 100));
+        } catch (err) {
+          console.error(`下载合同失败: ${contract.orderNo}`, err);
+        }
+      }
+
+      toast.success(`下载完成！成功 ${downloaded}/${total} 份`);
+
+      // 保存当前时间作为最后下载时间
+      const now = new Date().toISOString();
+      localStorage.setItem('contract_last_download_time', now);
+      setLastDownloadTime(now);
     } catch (error) {
       console.error('批量下载失败:', error);
       toast.error('批量下载失败，请重试');
     } finally {
       setBatchDownloading(false);
-      setBatchProgress(0);
+                  setDownloadProgress(0);
-      setDownloadStage('idle');
-      setDownloadProgress(0);
     }
   };
 
@@ -297,60 +277,91 @@ export default function ContractsPage() {
       return;
     }
 
+    // 检查浏览器是否支持选择目录
+    if (!('showDirectoryPicker' in window)) {
+      toast.error('当前浏览器不支持选择保存目录，请使用 Chrome 或 Edge 浏览器');
+      return;
+    }
+
+    // 第一步：让用户选择保存目录
+    let dirHandle: FileSystemDirectoryHandle;
+    try {
+      dirHandle = await (window as unknown as { showDirectoryPicker: () => Promise<FileSystemDirectoryHandle> }).showDirectoryPicker();
+    } catch (error: unknown) {
+      const err = error as Error;
+      if (err.name === 'AbortError') {
+        toast.info('已取消');
+      } else {
+        toast.error('选择保存目录失败');
+      }
+      return;
+    }
+
+    // 第二步：获取增量合同列表
     setBatchDownloading(true);
-    setBatchProgress(0);
+            setDownloadProgress(0);
-    setDownloadStage('packaging');
+    setDownloadedCount(0);
-    setDownloadProgress(0);
+    setTotalCount(0);
 
     try {
-      toast.info('正在准备增量下载，请稍候...');
+      toast.info('正在获取新增合同列表...');
 
-      const result = await contractService.createBatchDownload({
+      // 获取上次下载后新签署的合同
-        filters: {
+      const result = await contractService.getContracts({
-          signedAfter: lastDownloadTime,
+        signedAfter: lastDownloadTime,
-          provinceCode: filters.provinceCode || undefined,
+        provinceCode: filters.provinceCode || undefined,
-          cityCode: filters.cityCode || undefined,
+        cityCode: filters.cityCode || undefined,
-        },
+        status: 'SIGNED',
+        page: 1,
+        pageSize: 10000,
       });
 
-      // 轮询等待任务完成
+      const contracts = result.items.filter(c => c.signedPdfUrl);
-      const downloadUrl = await pollTaskUntilComplete(result.taskNo);
+      const total = contracts.length;
+      setTotalCount(total);
 
-      if (downloadUrl) {
+      if (total === 0) {
-        // 生成文件名
+        toast.info('没有新增的合同需要下载');
-        const today = new Date().toISOString().split('T')[0].replace(/-/g, '');
+        return;
-        const suggestedName = `contracts_incremental_${today}.zip`;
-
-        // 优先使用 File System Access API 让用户选择保存位置
-        toast.info('请选择保存位置...');
-        const saved = await saveFileWithPicker(downloadUrl, suggestedName);
-
-        if (saved) {
-          toast.success('文件保存成功！');
-        } else {
-          // 浏览器不支持或用户取消，使用备用方法
-          const link = document.createElement('a');
-          link.href = downloadUrl;
-          link.download = suggestedName;
-          document.body.appendChild(link);
-          link.click();
-          document.body.removeChild(link);
-          toast.success('下载已开始');
-        }
-
-        // 更新最后下载时间
-        const now = new Date().toISOString();
-        localStorage.setItem('contract_last_download_time', now);
-        setLastDownloadTime(now);
       }
+
+      toast.info(`开始下载 ${total} 份新增合同...`);
+
+      // 第三步：逐个下载合同
+      let downloaded = 0;
+      for (const contract of contracts) {
+        try {
+          const fileName = `${contract.contractNo}_${contract.userRealName || '未实名'}_${contract.treeCount}棵.pdf`;
+          const downloadUrl = contractService.getDownloadUrl(contract.orderNo);
+          const response = await fetch(downloadUrl);
+          if (!response.ok) continue;
+
+          const blob = await response.blob();
+          const fileHandle = await dirHandle.getFileHandle(fileName, { create: true });
+          const writable = await fileHandle.createWritable();
+          await writable.write(blob);
+          await writable.close();
+
+          downloaded++;
+          setDownloadedCount(downloaded);
+          setDownloadProgress(Math.round((downloaded / total) * 100));
+        } catch (err) {
+          console.error(`下载合同失败: ${contract.orderNo}`, err);
+        }
+      }
+
+      toast.success(`下载完成！成功 ${downloaded}/${total} 份`);
+
+      // 更新最后下载时间
+      const now = new Date().toISOString();
+      localStorage.setItem('contract_last_download_time', now);
+      setLastDownloadTime(now);
     } catch (error) {
       console.error('增量下载失败:', error);
       toast.error('增量下载失败，请重试');
     } finally {
       setBatchDownloading(false);
-      setBatchProgress(0);
+                  setDownloadProgress(0);
-      setDownloadStage('idle');
-      setDownloadProgress(0);
     }
   };
 
@@ -460,10 +471,8 @@ export default function ContractsPage() {
           <div className={styles.contracts__actions}>
             <Button variant="primary" onClick={handleBatchDownload} disabled={batchDownloading}>
               {batchDownloading
-                ? downloadStage === 'packaging'
+                ? `下载中 ${downloadedCount}/${totalCount}`
-                  ? `打包中 ${batchProgress}%`
+                : '批量下载'}
-                  : `下载中 ${downloadProgress}%`
-                : '批量下载 ZIP'}
             </Button>
             {lastDownloadTime && (
               <Button variant="outline" onClick={handleIncrementalDownload} disabled={batchDownloading}>
@@ -477,16 +486,16 @@ export default function ContractsPage() {
         {batchDownloading && (
           <div className={styles.contracts__progressContainer}>
             <div className={styles.contracts__progressLabel}>
-              {downloadStage === 'packaging' ? '正在打包合同文件...' : '正在下载到本地...'}
+              正在下载合同文件... ({downloadedCount}/{totalCount})
             </div>
             <div className={styles.contracts__progressBar}>
               <div
                 className={styles.contracts__progressFill}
-                style={{ width: `${downloadStage === 'packaging' ? batchProgress : downloadProgress}%` }}
+                style={{ width: `${downloadProgress}%` }}
               />
             </div>
             <div className={styles.contracts__progressText}>
-              {downloadStage === 'packaging' ? batchProgress : downloadProgress}%
+              {downloadProgress}%
             </div>
           </div>
         )}