download: use head for filename (nx)

Signed-off-by: Varun Patil <radialapps@gmail.com>

lib/Controller/DownloadController.php

@@ -90,7 +90,11 @@ class DownloadController extends GenericApiController
             $session = \OC::$server->get(ISession::class);
             $key = "memories_download_{$handle}";
             $info = $session->get($key);
+
+            // Remove handle from session unless HEAD request
+            if ('HEAD' !== $this->request->getMethod()) {
                 $session->remove($key);
+            }
 
             if (null === $info) {
                 throw Exceptions::NotFound('handle');
@@ -171,13 +175,17 @@ class DownloadController extends GenericApiController
             $out->setHeader('Content-Type: '.$file->getMimeType());
 
             // Make sure the browser downloads the file
-            $out->setHeader('Content-Disposition: attachment; filename="'.$file->getName().'"');
+            $filename = str_replace('"', '\\"', $file->getName());
+            $out->setHeader('Content-Disposition: attachment; filename="'.$filename.'"');
 
             // Prevent output from being buffered
             $out->setHeader('Content-Encoding: none');
             $out->setHeader('X-Content-Encoded-By: none');
             $out->setHeader('X-Accel-Buffering: no');
 
+            // Quit if HEAD request
+            if ('HEAD' === $this->request->getMethod()) return;
+
             // Open file to send
             $res = $file->fopen('rb');
 
@@ -255,6 +263,9 @@ class DownloadController extends GenericApiController
             // Create a zip file
             $streamer->sendHeaders($name);
 
+            // Quit if HEAD request
+            if ('HEAD' === $this->request->getMethod()) return;
+
             // Multiple files might have the same name
             // So we need to add a number to the end of the name
             $nameCounts = [];

src/native.ts

@@ -1,3 +1,4 @@
+import axios from '@nextcloud/axios';
 import type { IDay, IPhoto } from './types';
 
 const BASE_URL = 'http://127.0.0.1';
@@ -17,7 +18,7 @@ export const API = {
 export type NativeX = {
   isNative: () => boolean;
   setThemeColor: (color: string, isDark: boolean) => void;
-  downloadFromUrl: (url: string) => void;
+  downloadFromUrl: (url: string, filename: string) => void;
 };
 
 /** The native interface is a global object that is injected by the native app. */
@@ -45,7 +46,18 @@ export const setTheme = (color?: string, dark?: boolean) => {
 /**
  * Download a file from the given URL.
  */
-export const downloadFromUrl = (url: string) => nativex?.downloadFromUrl?.(url);
+export const downloadFromUrl = async (url: string) => {
+  // Make HEAD request to get filename
+  const res = await axios.head(url);
+  let filename = res.headers['content-disposition'];
+  if (res.status !== 200 || !filename) return;
+
+  // Extract filename from header without quotes
+  filename = filename.split('filename="')[1].slice(0, -1);
+
+  // Hand off to download manager
+  nativex?.downloadFromUrl?.(url, filename);
+};
 
 /**
  * Extend a list of days with local days.