fix: per-account push subscriptions so multi-account notifications work #298

app/api/push/preview/route.ts

@@ -1,10 +1,73 @@
+import { cookies } from 'next/headers';
 import { NextRequest, NextResponse } from 'next/server';
 import { logger } from '@/lib/logger';
-import { getStalwartCredentials } from '@/lib/stalwart/credentials';
+import { MAX_ACCOUNT_SLOTS } from '@/lib/account-utils';
+import { readStalwartAuthContextFromStore } from '@/lib/stalwart/auth-context';
+import {
+  getStalwartCredentials,
+  type StalwartCredentials,
+} from '@/lib/stalwart/credentials';
 
 export const runtime = 'nodejs';
 export const dynamic = 'force-dynamic';
 
+interface ResolvedTarget {
+  authHeader: string;
+  apiUrl: string;
+  accountId: string;
+}
+
+// When the SW passes ?accountId=, we need the slot whose JMAP session owns
+// that account - not just "the first signed-in slot", which is what
+// getStalwartCredentials() defaults to. Probe each candidate's session in
+// parallel and return the first match.
+async function resolveTargetForAccount(accountId: string): Promise<ResolvedTarget | null> {
+  const cookieStore = await cookies();
+  const probes: Promise<ResolvedTarget | null>[] = [];
+  for (let slot = 0; slot < MAX_ACCOUNT_SLOTS; slot++) {
+    const ctx = readStalwartAuthContextFromStore(cookieStore, slot);
+    if (!ctx) continue;
+    const serverUrl = ctx.serverUrl.replace(/\/+$/, '');
+    probes.push(
+      (async () => {
+        try {
+          const res = await fetch(`${serverUrl}/.well-known/jmap`, {
+            headers: { Authorization: ctx.authHeader },
+          });
+          if (!res.ok) return null;
+          const session = (await res.json()) as {
+            apiUrl?: string;
+            primaryAccounts?: Record<string, string>;
+          };
+          const mailAccountId = session.primaryAccounts?.['urn:ietf:params:jmap:mail'];
+          if (!session.apiUrl || !mailAccountId) return null;
+          if (mailAccountId !== accountId) return null;
+          return { authHeader: ctx.authHeader, apiUrl: session.apiUrl, accountId: mailAccountId };
+        } catch {
+          return null;
+        }
+      })(),
+    );
+  }
+  const results = await Promise.all(probes);
+  return results.find((r): r is ResolvedTarget => r !== null) ?? null;
+}
+
+async function resolveDefaultTarget(creds: StalwartCredentials): Promise<ResolvedTarget | null> {
+  const sessionRes = await fetch(`${creds.serverUrl}/.well-known/jmap`, {
+    headers: { Authorization: creds.authHeader },
+  });
+  if (!sessionRes.ok) return null;
+  const session = (await sessionRes.json()) as {
+    apiUrl?: string;
+    primaryAccounts?: Record<string, string>;
+  };
+  const apiUrl = session.apiUrl;
+  const accountId = session.primaryAccounts?.['urn:ietf:params:jmap:mail'];
+  if (!apiUrl || !accountId) return null;
+  return { authHeader: creds.authHeader, apiUrl, accountId };
+}
+
 /**
  * GET /api/push/preview
  *
@@ -19,31 +82,38 @@ export const dynamic = 'force-dynamic';
  */
 export async function GET(request: NextRequest) {
   try {
-    const creds = await getStalwartCredentials(request);
-    if (!creds) {
-      return NextResponse.json({ error: 'Not authenticated' }, { status: 401 });
+    // SW passes ?accountId=<jmap-account-id> derived from the push payload's
+    // StateChange so multi-account browsers fetch from the right slot. Older
+    // clients (and the manual /api/push/preview probe) omit it and fall back
+    // to the first signed-in slot.
+    const requestedAccountId = request.nextUrl.searchParams.get('accountId');
+
+    let target: ResolvedTarget | null = null;
+    let authHeader: string;
+    if (requestedAccountId) {
+      target = await resolveTargetForAccount(requestedAccountId);
+      if (!target) {
+        return NextResponse.json({ error: 'Not authenticated' }, { status: 401 });
+      }
+      authHeader = target.authHeader;
+    } else {
+      const creds = await getStalwartCredentials(request);
+      if (!creds) {
+        return NextResponse.json({ error: 'Not authenticated' }, { status: 401 });
+      }
+      target = await resolveDefaultTarget(creds);
+      if (!target) {
+        return NextResponse.json({ error: 'JMAP session failed' }, { status: 502 });
+      }
+      authHeader = creds.authHeader;
     }
 
-    const sessionRes = await fetch(`${creds.serverUrl}/.well-known/jmap`, {
-      headers: { Authorization: creds.authHeader },
-    });
-    if (!sessionRes.ok) {
-      return NextResponse.json({ error: 'JMAP session failed' }, { status: 502 });
-    }
-    const session = (await sessionRes.json()) as {
-      apiUrl?: string;
-      primaryAccounts?: Record<string, string>;
-    };
-    const apiUrl = session.apiUrl;
-    const accountId = session.primaryAccounts?.['urn:ietf:params:jmap:mail'];
-    if (!apiUrl || !accountId) {
-      return NextResponse.json({ error: 'Incomplete JMAP session' }, { status: 502 });
-    }
+    const { apiUrl, accountId } = target;
 
     const inboxRes = await fetch(apiUrl, {
       method: 'POST',
       headers: {
-        Authorization: creds.authHeader,
+        Authorization: authHeader,
         'Content-Type': 'application/json',
       },
       body: JSON.stringify({
@@ -119,7 +189,7 @@ export async function GET(request: NextRequest) {
     const jmapRes = await fetch(apiUrl, {
       method: 'POST',
       headers: {
-        Authorization: creds.authHeader,
+        Authorization: authHeader,
         'Content-Type': 'application/json',
       },
       body: JSON.stringify(requestBody),