Initial commit: teaching institution management API.

Express/MongoDB backend with JWT auth, RBAC, S3 uploads, notifications, and scheduled jobs.

components/files/fileService.js

@@ -0,0 +1,55 @@
+// /components/files/fileService.js
+
+const path = require('path');
+const {
+  uploadToTempBucket,
+  commitTempFile,
+  generatePresignedUrl,
+  deleteFromBucket
+} = require('../../utils/s3Client');
+const AppError = require('../../utils/AppError');
+
+const uploadTempFile = async (fileBuffer, originalName, mimeType) => {
+  if (!fileBuffer || !originalName) {
+    throw new AppError('FILE_REQUIRED');
+  }
+
+  const ext = path.extname(originalName);
+  const uniquePrefix = `${Date.now()}-${Math.round(Math.random() * 1E9)}`;
+  const tempFileName = `temp-${uniquePrefix}${ext}`;
+
+  const result = await uploadToTempBucket(fileBuffer, tempFileName, mimeType);
+  return {
+    tempFileName: result.tempFileName,
+    originalName,
+    mimeType
+  };
+};
+
+const getPresignedUrl = async (filename, bucket = null) => {
+  if (!filename) {
+    throw new AppError('VALIDATION_FAILED', null, 'Filename is required');
+  }
+
+  const signedUrl = await generatePresignedUrl(filename, bucket || undefined);
+  return {
+    filename,
+    presignedUrl: signedUrl,
+    expiresInSeconds: 900
+  };
+};
+
+const commitFile = async (tempFileName, targetFileName = null) => {
+  return commitTempFile(tempFileName, targetFileName);
+};
+
+const deleteFile = async (filename, bucket = null) => {
+  return deleteFromBucket(filename, bucket);
+};
+
+module.exports = {
+  uploadTempFile,
+  getPresignedUrl,
+  commitFile,
+  deleteFile
+};