feat(opensearch): Add BASE_URL config to support reverse proxy deployments

src/app/api/config/route.ts

@@ -1,5 +1,6 @@
 import {
   getAnthropicApiKey,
+  getBaseUrl,
   getCustomOpenaiApiKey,
   getCustomOpenaiApiUrl,
   getCustomOpenaiModelName,
@@ -60,6 +61,7 @@ export const GET = async (req: Request) => {
     config['customOpenaiApiUrl'] = getCustomOpenaiApiUrl();
     config['customOpenaiApiKey'] = getCustomOpenaiApiKey();
     config['customOpenaiModelName'] = getCustomOpenaiModelName();
+    config['baseUrl'] = getBaseUrl();
 
     return Response.json({ ...config }, { status: 200 });
   } catch (err) {

src/app/api/opensearch/route.ts

@@ -1,11 +1,10 @@
 import { NextResponse } from 'next/server';
+import { getBaseUrl } from '@/lib/config';
 
-export async function GET(request: Request) {
-  // Get the host from the request
-  const url = new URL(request.url);
-  const origin = url.origin;
-
-  // Create the OpenSearch XML with the correct origin
+/**
+ * Creates an OpenSearch XML response with the given origin URL
+ */
+function generateOpenSearchResponse(origin: string): NextResponse {
   const opensearchXml = `<?xml version="1.0" encoding="utf-8"?>
 <OpenSearchDescription xmlns="http://a9.com/-/spec/opensearch/1.1/" xmlns:moz="http://www.mozilla.org/2006/browser/search/">
   <ShortName>Perplexica</ShortName>
@@ -17,10 +16,48 @@ export async function GET(request: Request) {
   <Url type="application/opensearchdescription+xml" rel="self" template="${origin}/api/opensearch"/>
 </OpenSearchDescription>`;
 
-  // Return the XML with the correct content type
   return new NextResponse(opensearchXml, {
     headers: {
       'Content-Type': 'application/opensearchdescription+xml',
     },
   });
 }
+
+export async function GET(request: Request) {
+  // Check if a BASE_URL is explicitly configured
+  const configBaseUrl = getBaseUrl();
+  
+  // If BASE_URL is configured, use it, otherwise detect from request
+  if (configBaseUrl) {
+    // Remove any trailing slashes for consistency
+    let origin = configBaseUrl.replace(/\/+$/, '');
+    return generateOpenSearchResponse(origin);
+  }
+  
+  // Detect the correct origin, taking into account reverse proxy headers
+  const url = new URL(request.url);
+  let origin = url.origin;
+  
+  // Extract headers
+  const headers = Object.fromEntries(request.headers);
+  
+  // Check for X-Forwarded-Host and related headers to handle reverse proxies
+  if (headers['x-forwarded-host']) {
+    // Determine protocol: prefer X-Forwarded-Proto, fall back to original or https
+    const protocol = headers['x-forwarded-proto'] || url.protocol.replace(':', '');
+    // Build the correct public-facing origin
+    origin = `${protocol}://${headers['x-forwarded-host']}`;
+    
+    // Handle non-standard ports if specified in X-Forwarded-Port
+    if (headers['x-forwarded-port']) {
+      const port = headers['x-forwarded-port'];
+      // Don't append standard ports (80 for HTTP, 443 for HTTPS)
+      if (!((protocol === 'http' && port === '80') || (protocol === 'https' && port === '443'))) {
+        origin = `${origin}:${port}`;
+      }
+    }
+  }
+  
+  // Generate and return the OpenSearch response
+  return generateOpenSearchResponse(origin);
+}

src/lib/config.ts

@@ -15,6 +15,7 @@ interface Config {
   GENERAL: {
     SIMILARITY_MEASURE: string;
     KEEP_ALIVE: string;
+    BASE_URL?: string;
   };
   MODELS: {
     OPENAI: {
@@ -70,6 +71,8 @@ export const getSimilarityMeasure = () =>
 
 export const getKeepAlive = () => loadConfig().GENERAL.KEEP_ALIVE;
 
+export const getBaseUrl = () => loadConfig().GENERAL.BASE_URL;
+
 export const getOpenaiApiKey = () => loadConfig().MODELS.OPENAI.API_KEY;
 
 export const getGroqApiKey = () => loadConfig().MODELS.GROQ.API_KEY;