feat: add functionality to upload and update dataset metadata via CSV files

src/app/api/update-metadata/route.ts

@@ -0,0 +1,74 @@
+import { writeFile, mkdir, rm } from 'fs/promises';
+import { join } from 'path';
+import { existsSync } from 'fs';
+import { NextRequest, NextResponse } from 'next/server';
+import { requireAdmin } from '@/lib/auth';
+
+export async function POST(request: NextRequest) {
+  try {
+    const result = await requireAdmin();
+    if (!result.authenticated || !result.admin) {
+      return NextResponse.json(
+        { error: 'Unauthorized' },
+        { status: 401 }
+      );
+    }
+
+    const formData = await request.formData();
+    const file = formData.get('file') as File;
+    const datasetId = formData.get('datasetId') as string;
+
+    if (!file) {
+      return NextResponse.json(
+        { error: 'No file provided' },
+        { status: 400 }
+      );
+    }
+
+    if (!file.name.endsWith('.csv')) {
+      return NextResponse.json(
+        { error: 'File must be a CSV file' },
+        { status: 400 }
+      );
+    }
+
+    const tempDir = join(process.cwd(), 'tmp', `update-metadata-${Date.now()}`);
+
+    try {
+      // Create temp directory
+      await mkdir(tempDir, { recursive: true });
+
+      // Save uploaded CSV file as metadata.csv
+      const arrayBuffer = await file.arrayBuffer();
+      const buffer = Buffer.from(arrayBuffer);
+      const metadataPath = join(tempDir, 'metadata.csv');
+      await writeFile(metadataPath, buffer);
+
+      return NextResponse.json({
+        success: true,
+        tempDir,
+        message: `Successfully uploaded metadata.csv. Ready for processing.`,
+      });
+    } catch (error) {
+      // Clean up on error
+      try {
+        if (existsSync(tempDir)) {
+          await rm(tempDir, { recursive: true, force: true });
+        }
+      } catch (cleanupError) {
+        console.error('Error cleaning up temp directory:', cleanupError);
+      }
+
+      throw error;
+    }
+  } catch (error) {
+    console.error('Error uploading metadata CSV:', error);
+    const errorMsg =
+      error instanceof Error ? error.message : 'Failed to upload metadata CSV';
+    return NextResponse.json(
+      { error: errorMsg },
+      { status: 500 }
+    );
+  }
+}
+