fix: support Express IncomingHttpHeaders for client info extraction

- Add getHeaderValue() helper that works with multiple header formats:
  - Express req.get() method
  - Fetch API headers.get() method
  - Direct IncomingHttpHeaders object access
- Add isRequest() type guard to distinguish PayloadRequest from ClientInfo
- Use extractClientInfo() helper for consistent request/ClientInfo handling
- Apply same fix in auditAuthEvents.ts for hook context

This fixes the issue where PayloadRequest objects were incorrectly
detected as ClientInfo because IncomingHttpHeaders doesn't have .get()

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/hooks/auditAuthEvents.ts

@@ -62,19 +62,61 @@ export const auditAfterLogout: CollectionAfterLogoutHook = async ({ req }) => {
   console.log(`[Audit:Auth] Logout for ${user.email}`)
 }
 
+/**
+ * Extrahiert einen Header-Wert aus verschiedenen Header-Formaten
+ *
+ * Unterstützt:
+ * - Express/Node IncomingHttpHeaders (object mit lowercase keys)
+ * - Fetch API Headers (mit .get() Methode)
+ * - Request mit .get() Methode (Express-style)
+ */
+function getHeaderValue(req: PayloadRequest, headerName: string): string | undefined {
+  const lowerName = headerName.toLowerCase()
+
+  // 1. Versuche req.get() (Express Request Methode)
+  if (typeof (req as { get?: (name: string) => string | undefined }).get === 'function') {
+    const value = (req as { get: (name: string) => string | undefined }).get(lowerName)
+    if (value) return value
+  }
+
+  // 2. Versuche headers.get() (Fetch API Headers)
+  if (req.headers && typeof (req.headers as { get?: (name: string) => string | null }).get === 'function') {
+    const value = (req.headers as { get: (name: string) => string | null }).get(lowerName)
+    if (value) return value
+  }
+
+  // 3. Direkter Zugriff auf headers object (IncomingHttpHeaders)
+  if (req.headers && typeof req.headers === 'object') {
+    const headers = req.headers as Record<string, string | string[] | undefined>
+    const value = headers[lowerName]
+    if (typeof value === 'string') return value
+    if (Array.isArray(value) && value.length > 0) return value[0]
+  }
+
+  return undefined
+}
+
 /**
  * Extrahiert Client-Info aus einem PayloadRequest
+ *
+ * Funktioniert mit:
+ * - PayloadRequest (Express-basiert mit IncomingHttpHeaders)
+ * - Next.js Request (Fetch API basiert)
  */
 function extractClientInfo(req?: PayloadRequest): ClientInfo {
-  if (!req?.headers?.get) return {}
+  if (!req) return {}
 
-  const forwarded = req.headers.get('x-forwarded-for')
+  const forwarded = getHeaderValue(req, 'x-forwarded-for')
-  const realIp = req.headers.get('x-real-ip')
+  const realIp = getHeaderValue(req, 'x-real-ip')
-  const ipAddress =
-    (typeof forwarded === 'string' ? forwarded.split(',')[0]?.trim() : undefined) ||
-    (typeof realIp === 'string' ? realIp : undefined)
 
-  const userAgent = req.headers.get('user-agent') || undefined
+  let ipAddress: string | undefined
+  if (forwarded) {
+    ipAddress = forwarded.split(',')[0]?.trim()
+  } else if (realIp) {
+    ipAddress = realIp
+  }
+
+  const userAgent = getHeaderValue(req, 'user-agent')
 
   return { ipAddress, userAgent }
 }

src/lib/audit/audit-service.ts

@@ -50,21 +50,65 @@ export interface AuditLogInput {
   metadata?: Record<string, unknown>
 }
 
+/**
+ * Extrahiert einen Header-Wert aus verschiedenen Header-Formaten
+ *
+ * Unterstützt:
+ * - Express/Node IncomingHttpHeaders (object mit lowercase keys)
+ * - Fetch API Headers (mit .get() Methode)
+ * - Request mit .get() Methode (Express-style)
+ */
+function getHeaderValue(
+  req: PayloadRequest,
+  headerName: string,
+): string | undefined {
+  const lowerName = headerName.toLowerCase()
+
+  // 1. Versuche req.get() (Express Request Methode)
+  if (typeof (req as { get?: (name: string) => string | undefined }).get === 'function') {
+    const value = (req as { get: (name: string) => string | undefined }).get(lowerName)
+    if (value) return value
+  }
+
+  // 2. Versuche headers.get() (Fetch API Headers)
+  if (req.headers && typeof (req.headers as { get?: (name: string) => string | null }).get === 'function') {
+    const value = (req.headers as { get: (name: string) => string | null }).get(lowerName)
+    if (value) return value
+  }
+
+  // 3. Direkter Zugriff auf headers object (IncomingHttpHeaders)
+  if (req.headers && typeof req.headers === 'object') {
+    const headers = req.headers as Record<string, string | string[] | undefined>
+    const value = headers[lowerName]
+    if (typeof value === 'string') return value
+    if (Array.isArray(value) && value.length > 0) return value[0]
+  }
+
+  return undefined
+}
+
 /**
  * Extrahiert Client-Informationen aus dem Request
+ *
+ * Funktioniert mit:
+ * - PayloadRequest (Express-basiert mit IncomingHttpHeaders)
+ * - Next.js Request (Fetch API basiert)
  */
 function getClientInfo(req?: PayloadRequest): { ipAddress?: string; userAgent?: string } {
   if (!req) return {}
 
   // IP-Adresse aus verschiedenen Headern extrahieren
-  const forwarded = req.headers?.get?.('x-forwarded-for')
+  const forwarded = getHeaderValue(req, 'x-forwarded-for')
-  const realIp = req.headers?.get?.('x-real-ip')
+  const realIp = getHeaderValue(req, 'x-real-ip')
-  const ipAddress =
-    (typeof forwarded === 'string' ? forwarded.split(',')[0]?.trim() : undefined) ||
-    (typeof realIp === 'string' ? realIp : undefined) ||
-    'unknown'
 
-  const userAgent = req.headers?.get?.('user-agent') || undefined
+  let ipAddress: string | undefined
+  if (forwarded) {
+    ipAddress = forwarded.split(',')[0]?.trim()
+  } else if (realIp) {
+    ipAddress = realIp
+  }
+
+  const userAgent = getHeaderValue(req, 'user-agent')
 
   return { ipAddress, userAgent }
 }
@@ -156,6 +200,46 @@ export interface ClientInfo {
   userAgent?: string
 }
 
+/**
+ * Prüft ob ein Objekt ein Request ist (hat headers property)
+ * im Gegensatz zu einem einfachen ClientInfo-Objekt
+ */
+function isRequest(obj: unknown): obj is PayloadRequest {
+  if (!obj || typeof obj !== 'object') return false
+
+  // Ein Request hat typischerweise headers, method, url etc.
+  // ClientInfo hat nur ipAddress und/oder userAgent
+  const asRecord = obj as Record<string, unknown>
+
+  // Wenn es headers hat, ist es ein Request
+  if ('headers' in asRecord) return true
+
+  // Wenn es method oder url hat, ist es ein Request
+  if ('method' in asRecord || 'url' in asRecord) return true
+
+  // Wenn es NUR ipAddress und/oder userAgent hat, ist es ClientInfo
+  const keys = Object.keys(asRecord)
+  const clientInfoKeys = ['ipAddress', 'userAgent']
+  if (keys.every((key) => clientInfoKeys.includes(key))) return false
+
+  // Im Zweifel als Request behandeln
+  return true
+}
+
+/**
+ * Extrahiert ClientInfo aus einem Request oder gibt das übergebene ClientInfo zurück
+ */
+function extractClientInfo(reqOrClientInfo?: PayloadRequest | ClientInfo): ClientInfo {
+  if (!reqOrClientInfo) return {}
+
+  if (isRequest(reqOrClientInfo)) {
+    return getClientInfo(reqOrClientInfo)
+  }
+
+  // Es ist bereits ClientInfo
+  return reqOrClientInfo
+}
+
 /**
  * Loggt einen fehlgeschlagenen Login
  *
@@ -170,18 +254,7 @@ export async function logLoginFailed(
   reason: string,
   reqOrClientInfo?: PayloadRequest | ClientInfo,
 ): Promise<void> {
-  // Unterscheide zwischen PayloadRequest und direktem ClientInfo
+  const clientInfo = extractClientInfo(reqOrClientInfo)
-  let clientInfo: ClientInfo = {}
-
-  if (reqOrClientInfo) {
-    if ('headers' in reqOrClientInfo && typeof reqOrClientInfo.headers?.get === 'function') {
-      // Es ist ein PayloadRequest - extrahiere Client-Info
-      clientInfo = getClientInfo(reqOrClientInfo as PayloadRequest)
-    } else {
-      // Es ist direktes ClientInfo
-      clientInfo = reqOrClientInfo as ClientInfo
-    }
-  }
 
   await createAuditLog(
     payload,
@@ -211,16 +284,7 @@ export async function logPasswordReset(
   email: string,
   reqOrClientInfo?: PayloadRequest | ClientInfo,
 ): Promise<void> {
-  // Unterscheide zwischen PayloadRequest und direktem ClientInfo
+  const clientInfo = extractClientInfo(reqOrClientInfo)
-  let clientInfo: ClientInfo = {}
-
-  if (reqOrClientInfo) {
-    if ('headers' in reqOrClientInfo && typeof reqOrClientInfo.headers?.get === 'function') {
-      clientInfo = getClientInfo(reqOrClientInfo as PayloadRequest)
-    } else {
-      clientInfo = reqOrClientInfo as ClientInfo
-    }
-  }
 
   await createAuditLog(
     payload,