From 037bda30c6c52aeb37f8b6bdae06a4fe0bf8fe22 Mon Sep 17 00:00:00 2001
From: GitHub Copilot <copilot@openai.com>
Date: Tue, 5 May 2026 11:49:02 +0800
Subject: [PATCH] fix: download output files via CDN with required query params
 (fixes #369)

---
 src/api/base.ts                      | 43 ++++++++++++++++++++++++++--
 src/core/remoteFileSystemProvider.ts | 10 ++++++-
 2 files changed, 50 insertions(+), 3 deletions(-)

diff --git a/src/api/base.ts b/src/api/base.ts
index f81f1d76..55470237 100644
--- a/src/api/base.ts
+++ b/src/api/base.ts
@@ -21,6 +21,8 @@ export interface NewProjectResponseSchema {
 export interface CompileResponseSchema {
     status: 'success' | 'failure' | 'error';
     compileGroup: string;
+    clsiServerId?: string;
+    pdfDownloadDomain?: string;
     outputFiles: Array<OutputFileEntity>;
     stats: {
         "latexmk-errors":number, "pdf-size":number,
@@ -684,9 +686,20 @@ export class BaseAPI {
         return this.request('POST', `project/${projectId}/settings`, setting);
     }
 
-    async getFileFromClsi(identity:Identity, url:string, compileGroup:string) {
-        url = url.replace(/^\/+/g, '');
+    async getFileFromClsi(identity:Identity, url:string, compileGroup:string, clsiServerId?:string, pdfDownloadDomain?:string) {
+        // If we have a CDN download domain, construct the full URL with required query params.
+        // The CDN is cross-origin, so we must NOT send web frontend cookies.
+        if (pdfDownloadDomain && clsiServerId) {
+            const cdnUrl = `${pdfDownloadDomain.replace(/\/+$/, '')}/${url.replace(/^\/+/g, '')}` +
+                `?compileGroup=${encodeURIComponent(compileGroup)}` +
+                `&clsiserverid=${encodeURIComponent(clsiServerId)}` +
+                `&enable_pdf_caching=true`;
+            const content = await this._downloadAbsolute(cdnUrl, false);
+            return { type: 'success', content: new Uint8Array(content) };
+        }
 
+        // Fallback: download from web frontend (legacy path)
+        url = url.replace(/^\/+/g, '');
         this.setIdentity(identity);
         const content = await this.download(url);
         return {
@@ -695,6 +708,32 @@ export class BaseAPI {
         };
     }
 
+    /** Download from an absolute URL, optionally including web frontend cookies. */
+    private async _downloadAbsolute(absoluteUrl: string, includeCookies: boolean): Promise<Buffer> {
+        const headers: Record<string, string> = {
+            'Connection': 'keep-alive',
+        };
+        if (includeCookies && this.identity) {
+            headers['Cookie'] = this.identity.cookies;
+        }
+        let content: Buffer[] = [];
+        while (true) {
+            const res = await fetch(absoluteUrl, {
+                method: 'GET', redirect: 'manual', agent: this.agent,
+                headers
+            });
+            if (res.status === 200) {
+                content.push(await res.buffer());
+                break;
+            } else if (res.status === 206) {
+                content.push(await res.buffer());
+            } else {
+                break;
+            }
+        }
+        return Buffer.concat(content);
+    }
+
     async proxySyncPdf(identity:Identity, projectId:string, page:number, h:number, v:number, buildId:string) {
         this.setIdentity(identity);
         const request = `project/${projectId}/sync/pdf?page=${page}&h=${h.toFixed(2)}&v=${v.toFixed(2)}&editorId=${uuidv4()}&buildId=${buildId}`;
diff --git a/src/core/remoteFileSystemProvider.ts b/src/core/remoteFileSystemProvider.ts
index 176e8ac5..7c0a8eec 100644
--- a/src/core/remoteFileSystemProvider.ts
+++ b/src/core/remoteFileSystemProvider.ts
@@ -118,6 +118,9 @@ export class VirtualFileSystem extends vscode.Disposable {
     private initializing?: Promise<ProjectEntity>;
     private retryConnection: number = 0;
     private outputBuildId?: string;
+    private compileGroup?: string;
+    private clsiServerId?: string;
+    private pdfDownloadDomain?: string;
     private notify: (events:vscode.FileChangeEvent[])=>void;
     private clientManagerItem?: {manager: ClientManager, triggers: vscode.Disposable[]};
     private scmCollectionItem?: {collection: SCMCollectionProvider, triggers: vscode.Disposable[]};
@@ -531,9 +534,10 @@ export class VirtualFileSystem extends vscode.Disposable {
                 return new TextEncoder().encode(content);
             }
         } else if (fileType==='outputs') {
+            const {compileGroup, clsiServerId, pdfDownloadDomain} = this;
             return GlobalStateManager.authenticate(this.context, this.serverName)
             .then((identity) => {
-                return this.api.getFileFromClsi(identity, (fileEntity as OutputFileEntity).url, 'standard')
+                return this.api.getFileFromClsi(identity, (fileEntity as OutputFileEntity).url, compileGroup || 'standard', clsiServerId, pdfDownloadDomain)
                 .then((res) => {
                     if (res.type==='success') {
                         EventBus.fire('fileWillOpenEvent', {uri});
@@ -896,6 +900,10 @@ export class VirtualFileSystem extends vscode.Disposable {
             }
             const res = await this.api.compile(identity, this.projectId, rootResourcePath, draft, stopOnFirstError);
             if (res.type==='success' && res.compile?.status==='success') {
+                // Store CDN download info from the response for subsequent output file requests
+                this.compileGroup = res.compile.compileGroup;
+                this.clsiServerId = res.compile.clsiServerId;
+                this.pdfDownloadDomain = res.compile.pdfDownloadDomain;
                 this.updateOutputs(res.compile.outputFiles);
                 return true;
             } else {