WebUI/WebAPI: Support downloading torrent via search plugin

This adds support for downloading a torrent via a search plugin's `download_torrent` function. This primarily affects torrents that use a private tracker requiring a login.

Closes #18334.
PR #23163.

src/webui/www/private/addtorrent.html

@@ -49,6 +49,13 @@
             const windowId = searchParams.get("windowId");
             window.qBittorrent.AddTorrent.setWindowId(windowId);
 
+            const downloader = searchParams.get("downloader");
+            if (downloader?.length > 0) {
+                const downloaderInput = document.getElementById("downloader");
+                downloaderInput.value = downloader;
+                downloaderInput.disabled = false;
+            }
+
             document.getElementById("uploadForm").addEventListener("submit", (event) => {
                 submitted = true;
                 window.qBittorrent.AddTorrent.submitForm();
@@ -81,7 +88,7 @@
             window.qBittorrent.TorrentContent.init("addTorrentFilesTableDiv", window.qBittorrent.DynamicTable.AddTorrentFilesTable);
 
             if (fetchMetadata)
-                window.qBittorrent.AddTorrent.loadMetadata(source);
+                window.qBittorrent.AddTorrent.loadMetadata(source, downloader);
         });
     </script>
 
@@ -144,6 +151,7 @@
     <form action="api/v2/torrents/add" enctype="multipart/form-data" method="post" id="uploadForm" style="text-align: center; padding: 10px 12px;" target="upload_frame" autocorrect="off" autocapitalize="none">
         <input type="hidden" id="urls" name="urls">
         <input type="hidden" id="filePriorities" name="filePriorities">
+        <input type="hidden" id="downloader" name="downloader" disabled>
         <div class="container">
             <div class="column">
                 <fieldset class="settings" style="text-align: left;">

src/webui/www/private/scripts/addtorrent.js

@@ -42,6 +42,7 @@ window.qBittorrent.AddTorrent ??= (() => {
     let defaultTempPathEnabled = false;
     let windowId = "";
     let source = "";
+    let downloader = "";
 
     const localPreferences = new window.qBittorrent.LocalPreferences.LocalPreferences();
 
@@ -214,14 +215,17 @@ window.qBittorrent.AddTorrent ??= (() => {
     };
 
     let loadMetadataTimer = -1;
-    const loadMetadata = (sourceUrl = undefined) => {
+    const loadMetadata = (sourceUrl = undefined, downloaderName = undefined) => {
         if (sourceUrl !== undefined)
             source = sourceUrl;
+        if (downloaderName !== undefined)
+            downloader = downloaderName;
 
         fetch("api/v2/torrents/fetchMetadata", {
                 method: "POST",
                 body: new URLSearchParams({
-                    source: source
+                    source: source,
+                    downloader: downloader
                 })
             })
             .then(async (response) => {

src/webui/www/private/scripts/client.js

@@ -130,7 +130,7 @@ window.qBittorrent.Client ??= (() => {
         return showingLogViewer;
     };
 
-    const createAddTorrentWindow = (title, source, metadata = undefined) => {
+    const createAddTorrentWindow = (title, source, metadata = undefined, downloader = undefined) => {
         const isFirefox = navigator.userAgent.includes("Firefox");
         const isSafari = navigator.userAgent.includes("AppleWebKit") && !navigator.userAgent.includes("Chrome");
         let height = 855;
@@ -147,7 +147,8 @@ window.qBittorrent.Client ??= (() => {
             v: "${CACHEID}",
             source: source,
             fetch: metadata === undefined,
-            windowId: id
+            windowId: id,
+            downloader: downloader ?? ""
         });
 
         new MochaUI.Window({

src/webui/www/private/scripts/search.js

@@ -561,8 +561,8 @@ window.qBittorrent.Search ??= (() => {
 
     const downloadSearchTorrent = () => {
         for (const rowID of searchResultsTable.selectedRowsIds()) {
-            const { fileName, fileUrl } = searchResultsTable.getRow(rowID).full_data;
-            qBittorrent.Client.createAddTorrentWindow(fileName, fileUrl);
+            const { engineName, fileName, fileUrl } = searchResultsTable.getRow(rowID).full_data;
+            qBittorrent.Client.createAddTorrentWindow(fileName, fileUrl, undefined, engineName);
         }
     };