fix: preserve POST across redirects in Stalwart JMAP passthrough #627

app/api/account/stalwart/jmap/route.ts

@@ -1,6 +1,7 @@
 import { NextRequest, NextResponse } from 'next/server';
 import { logger } from '@/lib/logger';
 import { getStalwartCredentials } from '@/lib/stalwart/credentials';
+import { JmapRedirectError, fetchJmapSession, postJmap, rebaseApiUrl } from '@/lib/stalwart/jmap-api';
 
 /**
  * POST /api/account/stalwart/jmap
@@ -23,14 +24,26 @@ export async function POST(request: NextRequest) {
 
     const body = await request.text();
 
-    const response = await fetch(`${creds.serverUrl}/jmap/`, {
-      method: 'POST',
-      headers: {
-        'Authorization': creds.authHeader,
-        'Content-Type': 'application/json',
-      },
-      body,
-    });
+    const directUrl = `${creds.serverUrl}/jmap/`;
+    let response = await postJmap(directUrl, creds.authHeader, body);
+
+    if (response.status === 404) {
+      // `${serverUrl}/jmap/` is not the API endpoint on this deployment
+      // (path prefix, non-Stalwart URL layout). Resolve the session's
+      // advertised apiUrl on the same host and retry once.
+      const session = await fetchJmapSession(creds.serverUrl, creds.authHeader);
+      const apiUrl = rebaseApiUrl(session, creds.serverUrl);
+      if (apiUrl && apiUrl !== directUrl) {
+        response = await postJmap(apiUrl, creds.authHeader, body);
+      }
+    }
+
+    if (!response.ok) {
+      logger.warn('Stalwart JMAP passthrough upstream error', {
+        status: response.status,
+        serverUrl: creds.serverUrl,
+      });
+    }
 
     const responseText = await response.text();
     return new NextResponse(responseText, {
@@ -38,6 +51,10 @@ export async function POST(request: NextRequest) {
       headers: { 'Content-Type': response.headers.get('Content-Type') || 'application/json' },
     });
   } catch (error) {
+    if (error instanceof JmapRedirectError) {
+      logger.error('Stalwart JMAP passthrough redirect error', { error: error.message });
+      return NextResponse.json({ error: error.message }, { status: 502 });
+    }
     logger.error('Stalwart JMAP passthrough error', {
       error: error instanceof Error ? error.message : 'Unknown',
     });