added download list

src/app/actions/get-available-downloads.ts

@@ -0,0 +1,63 @@
+'use server';
+
+import { readdirSync, unlinkSync } from 'fs';
+import { join } from 'path';
+import { requireAdmin } from '@/lib/auth';
+
+interface DownloadFile {
+  name: string;
+  url: string;
+}
+
+export async function getAvailableDownloads(datasetId: number): Promise<DownloadFile[]> {
+  const result = await requireAdmin();
+  if (!result.authenticated || !result.admin) {
+    throw new Error('Unauthorized');
+  }
+
+  try {
+    const downloadsDir = join(process.cwd(), 'public', 'downloads');
+    const files = readdirSync(downloadsDir);
+    
+    const pattern = new RegExp(`^dataset-${datasetId}-export-`);
+    const matching = files.filter(file => pattern.test(file) && file.endsWith('.zip'));
+    
+    // Sort by timestamp descending (most recent first)
+    matching.sort().reverse();
+    
+    return matching.map(file => ({
+      name: file,
+      url: `/public/downloads/${file}`
+    }));
+  } catch (error) {
+    console.error('Error fetching available downloads:', error);
+    throw new Error('Failed to fetch available downloads');
+  }
+}
+
+export async function deleteDownload(fileName: string): Promise<void> {
+  const result = await requireAdmin();
+  if (!result.authenticated || !result.admin) {
+    throw new Error('Unauthorized');
+  }
+
+  try {
+    // Validate filename to prevent directory traversal attacks
+    if (fileName.includes('..') || fileName.includes('/') || fileName.includes('\\')) {
+      throw new Error('Invalid filename');
+    }
+
+    const downloadsDir = join(process.cwd(), 'public', 'downloads');
+    const filePath = join(downloadsDir, fileName);
+    
+    // Ensure the file is within the downloads directory
+    if (!filePath.startsWith(downloadsDir)) {
+      throw new Error('Invalid file path');
+    }
+
+    unlinkSync(filePath);
+  } catch (error) {
+    console.error('Error deleting download:', error);
+    throw new Error('Failed to delete download');
+  }
+}