fix(portal): add invitation links and correct customer login routing

backend/src/routes/admin.ts

@@ -33,6 +33,7 @@ import { requireSystemAdmin } from "../utils/requireSystemAdmin";
 import { buildSystemStatus } from "../modules/system-status.service";
 import { s3 } from "../utils/s3";
 import { secrets } from "../utils/secrets";
+import { getPortalLoginUrl } from "../utils/portalUrl";
 
 export default async function adminRoutes(server: FastifyInstance) {
     await server.register(multipart, {
@@ -931,6 +932,17 @@ export default async function adminRoutes(server: FastifyInstance) {
                 return reply.code(400).send({ error: "Customer has no email address" });
             }
 
+            let portalUrl: string;
+            try {
+                portalUrl = getPortalLoginUrl({
+                    portalDomain: tenantRecord?.portalDomain,
+                    publicUrl: process.env.FEDEO_PUBLIC_URL,
+                    apiBaseUrl: secrets.API_BASE_URL,
+                });
+            } catch (err: any) {
+                return reply.code(503).send({ error: err.message });
+            }
+
             const generatedPassword = generateRandomPassword(14);
             const passwordHash = await hashPassword(generatedPassword);
 
@@ -1086,8 +1098,6 @@ export default async function adminRoutes(server: FastifyInstance) {
                     });
             }
 
-            const portalUrl = tenantRecord?.portalDomain ? `https://${tenantRecord.portalDomain}/login` : null;
-
             const mailResult = await sendMail(
                 email,
                 `FEDEO | Einladung ins Kundenportal`,
@@ -1097,7 +1107,8 @@ export default async function adminRoutes(server: FastifyInstance) {
                     <p><strong>E-Mail:</strong> ${email}</p>
                     <p><strong>Initialpasswort:</strong> ${generatedPassword}</p>
                     <p>Bitte ändern Sie dieses Passwort direkt nach dem ersten Login.</p>
-                    ${portalUrl ? `<p><strong>Login:</strong> <a href="${portalUrl}">${portalUrl}</a></p>` : ""}
+                    <p><a href="${portalUrl}">Zum Kundenportal anmelden</a></p>
+                    <p>Ihre Login-Adresse: ${portalUrl}</p>
                     <p>Viele Grüße<br>${tenantRecord?.name || "FEDEO"}</p>
                 `
             );

backend/src/routes/auth/auth.ts

@@ -7,6 +7,7 @@ import { authUsers } from "../../../db/schema";
 import { authTenantUsers } from "../../../db/schema";
 import { tenants } from "../../../db/schema";
 import { and, eq } from "drizzle-orm";
+import { resolveLoginTenant } from "../../utils/loginTenant";
 import {
     createAccessToken,
     issueRefreshToken,
@@ -127,7 +128,7 @@ export default async function authRoutes(server: FastifyInstance) {
             return reply.code(401).send({ error: "Invalid credentials" });
         }
 
-        const tenantId = req.tenant?.id ? Number(req.tenant.id) : null;
+        const tenantId = await resolveLoginTenant(server, user.id, req.tenant?.id ? Number(req.tenant.id) : null);
         const token = createAccessToken(user, tenantId);
         const refreshToken = await issueRefreshToken(server, user.id, tenantId);
 

backend/src/utils/loginTenant.ts

@@ -0,0 +1,33 @@
+import type { FastifyInstance } from "fastify"
+import { and, eq } from "drizzle-orm"
+import { authProfiles, authTenantUsers } from "../../db/schema"
+
+export async function resolveLoginTenant(server: FastifyInstance, userId: string, domainTenantId: number | null) {
+    const memberships = await server.db
+        .selectDistinct({
+            tenantId: authTenantUsers.tenant_id,
+            portalCustomerId: authProfiles.customer_for_portal,
+        })
+        .from(authTenantUsers)
+        .leftJoin(authProfiles, and(
+            eq(authProfiles.user_id, authTenantUsers.user_id),
+            eq(authProfiles.tenant_id, authTenantUsers.tenant_id),
+            eq(authProfiles.active, true)
+        ))
+        .where(eq(authTenantUsers.user_id, userId))
+
+    if (domainTenantId) {
+        if (!memberships.some((membership) => membership.tenantId === domainTenantId)) {
+            throw Object.assign(new Error("Not a member of this tenant"), { statusCode: 403 })
+        }
+        return domainTenantId
+    }
+
+    // Portal invitations assign one customer account. Load its profile immediately,
+    // even when the customer signs in through the shared FEDEO address.
+    if (memberships.length === 1 && memberships[0].portalCustomerId) {
+        return memberships[0].tenantId
+    }
+
+    return null
+}

backend/src/utils/portalUrl.ts

@@ -0,0 +1,29 @@
+type PortalUrlSettings = {
+    portalDomain?: string | null
+    publicUrl?: string
+    apiBaseUrl?: string
+}
+
+/** Use deployment configuration, never request headers, for links sent by email. */
+export function getPortalLoginUrl({ portalDomain, publicUrl, apiBaseUrl }: PortalUrlSettings) {
+    const domain = portalDomain?.trim()
+    const candidates = [
+        { value: domain ? (/^https?:\/\//i.test(domain) ? domain : `https://${domain}`) : undefined },
+        { value: publicUrl?.trim() },
+        { value: apiBaseUrl?.trim(), originOnly: true },
+    ]
+
+    for (const { value, originOnly } of candidates) {
+        if (!value) continue
+        try {
+            const url = new URL(value)
+            if (!["http:", "https:"].includes(url.protocol) || url.username || url.password) continue
+            url.pathname = `${originOnly ? "" : url.pathname.replace(/\/+$/, "")}/login`
+            url.search = ""
+            url.hash = ""
+            return url.toString()
+        } catch { /* Try the next configured address. */ }
+    }
+
+    throw new Error("Für die Portal-Einladung fehlt eine gültige öffentliche FEDEO-Adresse.")
+}