Import source: backend/src/utils/gdrive

Import the existing local project snapshot. This commit organizes existing files; it does not represent newly developed functionality.

backend/src/utils/gdrive.ts

@@ -0,0 +1,69 @@
+import { google } from 'googleapis';
+import type { Readable } from 'node:stream';
+import { env } from '../config/env.js';
+
+const auth = new google.auth.OAuth2(env.gdriveClientId, env.gdriveClientSecret);
+auth.setCredentials({ refresh_token: env.gdriveRefreshToken });
+
+const drive = google.drive({ version: 'v3', auth });
+
+/**
+ * Upload a stream directly to Google Drive.
+ * Uses the Drive API's resumable upload — no rclone process, no disk writes.
+ * Returns the new file's Drive ID.
+ */
+export async function uploadStream(
+  stream: Readable,
+  filename: string,
+  mimeType: string,
+): Promise<string> {
+  const res = await drive.files.create({
+    requestBody: {
+      name: filename,
+      parents: [env.gdriveFolderId],
+    },
+    media: {
+      mimeType: mimeType || 'application/octet-stream',
+      body: stream,
+    },
+    fields: 'id',
+  });
+
+  if (!res.data.id) throw new Error('GDrive upload returned no file ID');
+  return res.data.id;
+}
+
+/**
+ * Stream file content from Drive for inline preview.
+ * Returns a readable stream — no disk writes on the server.
+ */
+export async function getStream(fileId: string): Promise<Readable> {
+  const res = await drive.files.get(
+    { fileId, alt: 'media' },
+    { responseType: 'stream' },
+  );
+  return res.data as unknown as Readable;
+}
+
+/** Permanently delete a file from Drive. Silently ignores 404. */
+export async function deleteFile(fileId: string): Promise<void> {
+  await drive.files.delete({ fileId }).catch((err: { code?: number }) => {
+    if (err.code !== 404) throw err;
+  });
+}
+
+/** Direct download URL — bypasses Drive's antivirus interstitial for large files. */
+export function downloadUrl(fileId: string): string {
+  return `https://drive.usercontent.google.com/download?id=${fileId}&export=download&confirm=t`;
+}
+
+/** Lightweight connectivity check: lists 1 file in our folder. Returns false on any error. */
+export async function checkGdriveHealth(): Promise<boolean> {
+  if (!env.gdriveClientId) return false;
+  try {
+    await drive.files.list({ q: `'${env.gdriveFolderId}' in parents`, pageSize: 1, fields: 'files(id)' });
+    return true;
+  } catch {
+    return false;
+  }
+}