From f75adfe6a3d71f9629d6ad73f844e128506aa62c Mon Sep 17 00:00:00 2001
From: Elian Doran <contact@eliandoran.me>
Date: Sun, 12 Apr 2026 19:03:07 +0300
Subject: [PATCH] fix(standalone): PDFjs not working in dev mode

---
 apps/client-standalone/src/sw.ts       | 18 ++++--
 apps/client-standalone/vite.config.mts | 83 ++++++++++++++++++++++----
 2 files changed, 87 insertions(+), 14 deletions(-)

diff --git a/apps/client-standalone/src/sw.ts b/apps/client-standalone/src/sw.ts
index 630d09acd9..4e5b5831f7 100644
--- a/apps/client-standalone/src/sw.ts
+++ b/apps/client-standalone/src/sw.ts
@@ -85,12 +85,22 @@ async function networkFirst(request) {
     }
 }
 
-async function forwardToClientLocalServer(request, clientId) {
-    // Find a client to handle the request (prefer the initiating client if available)
-    let client = clientId ? await self.clients.get(clientId) : null;
+async function forwardToClientLocalServer(request, _clientId) {
+    // Find the main app window to handle the request
+    // We must route to the main app (which has the local bridge), not iframes like PDF.js viewer
+    // @ts-expect-error - self.clients is valid in service worker context
+    const all = await self.clients.matchAll({ type: "window", includeUncontrolled: true });
 
+    // Find the main app window - it's the one NOT serving pdfjs or other embedded content
+    // The main app has the local bridge handler for LOCAL_FETCH messages
+    let client = all.find((c: { url: string }) => {
+        const url = new URL(c.url);
+        // Main app is at root or index.html, not in /pdfjs/ or other iframe paths
+        return !url.pathname.startsWith("/pdfjs/");
+    }) || null;
+
+    // If no main app window found, fall back to any available client
     if (!client) {
-        const all = await self.clients.matchAll({ type: "window", includeUncontrolled: true });
         client = all[0] || null;
     }
 
diff --git a/apps/client-standalone/vite.config.mts b/apps/client-standalone/vite.config.mts
index ea92dd7855..0d5a7a9c9d 100644
--- a/apps/client-standalone/vite.config.mts
+++ b/apps/client-standalone/vite.config.mts
@@ -1,7 +1,9 @@
-import prefresh from '@prefresh/vite';
-import { join } from 'path';
-import { defineConfig } from 'vite';
-import { viteStaticCopy } from 'vite-plugin-static-copy';
+import fs from "fs";
+import { join } from "path";
+
+import prefresh from "@prefresh/vite";
+import { defineConfig, type Plugin } from "vite";
+import { viteStaticCopy } from "vite-plugin-static-copy";
 
 const clientAssets = ["assets", "stylesheets", "fonts", "translations"];
 
@@ -9,15 +11,15 @@ const isDev = process.env.NODE_ENV === "development";
 
 // Watch client files and trigger reload in development
 const clientWatchPlugin = () => ({
-    name: 'client-watch',
+    name: "client-watch",
     configureServer(server: any) {
         if (isDev) {
             // Watch client source files (adjusted for new root)
-            server.watcher.add('../../client/src/**/*');
-            server.watcher.on('change', (file: string) => {
-                if (file.includes('../../client/src/')) {
+            server.watcher.add("../../client/src/**/*");
+            server.watcher.on("change", (file: string) => {
+                if (file.includes("../../client/src/")) {
                     server.ws.send({
-                        type: 'full-reload'
+                        type: "full-reload"
                     });
                 }
             });
@@ -25,6 +27,53 @@ const clientWatchPlugin = () => ({
     }
 });
 
+// Serve PDF.js files directly in dev mode to bypass SPA fallback
+const pdfjsServePlugin = (): Plugin => ({
+    name: "pdfjs-serve",
+    configureServer(server) {
+        const pdfjsRoot = join(__dirname, "../../packages/pdfjs-viewer/dist");
+
+        server.middlewares.use((req, res, next) => {
+            if (!req.url?.startsWith("/pdfjs/")) {
+                return next();
+            }
+
+            // Map /pdfjs/web/... to dist/web/...
+            // Map /pdfjs/build/... to dist/build/...
+            // Strip query string (e.g., ?v=0.102.2) before resolving path
+            const urlWithoutQuery = req.url.split("?")[0];
+            const relativePath = urlWithoutQuery.replace(/^\/pdfjs\//, "");
+            const filePath = join(pdfjsRoot, relativePath);
+
+            // Security: ensure we're still within pdfjsRoot
+            if (!filePath.startsWith(pdfjsRoot)) {
+                return next();
+            }
+
+            if (fs.existsSync(filePath) && fs.statSync(filePath).isFile()) {
+                const ext = filePath.split(".").pop() || "";
+                const mimeTypes: Record<string, string> = {
+                    html: "text/html",
+                    css: "text/css",
+                    js: "application/javascript",
+                    mjs: "application/javascript",
+                    wasm: "application/wasm",
+                    png: "image/png",
+                    svg: "image/svg+xml",
+                    json: "application/json"
+                };
+                res.setHeader("Content-Type", mimeTypes[ext] || "application/octet-stream");
+                // Match isolation headers from main page for iframe compatibility
+                res.setHeader("Cross-Origin-Opener-Policy", "same-origin");
+                res.setHeader("Cross-Origin-Embedder-Policy", "require-corp");
+                fs.createReadStream(filePath).pipe(res);
+            } else {
+                next();
+            }
+        });
+    }
+});
+
 // Always copy SQLite WASM files so they're available to the module
 const sqliteWasmPlugin = viteStaticCopy({
     targets: [
@@ -65,10 +114,24 @@ let plugins: any = [
             }
         ]
     }),
+    // PDF.js viewer for PDF preview support
+    viteStaticCopy({
+        targets: [
+            {
+                src: join(__dirname, "../../packages/pdfjs-viewer/dist/web/**/*"),
+                dest: "pdfjs/web",
+            },
+            {
+                src: join(__dirname, "../../packages/pdfjs-viewer/dist/build/**/*"),
+                dest: "pdfjs/build",
+            }
+        ]
+    }),
     // Watch client files for changes in development
     ...(isDev ? [
         prefresh(),
-        clientWatchPlugin()
+        clientWatchPlugin(),
+        pdfjsServePlugin()
     ] : [])
 ];