From 9e80aa1d7039dd6191c0135130dac877116eff41 Mon Sep 17 00:00:00 2001
From: Erik Silva <erik@stackbyte.cloud>
Date: Tue, 9 Dec 2025 03:04:28 -0300
Subject: [PATCH] feat: block unknown subdomains via tenant check

---
 backend/cmd/server/main.go                 |  1 +
 backend/internal/api/handlers/tenant.go    | 28 ++++++++++++++++++++++
 backend/internal/service/tenant_service.go |  5 ++++
 front-end-dash.aggios.app/middleware.ts    | 18 +++++++++++++-
 4 files changed, 51 insertions(+), 1 deletion(-)

diff --git a/backend/cmd/server/main.go b/backend/cmd/server/main.go
index df04750..6c981d6 100644
--- a/backend/cmd/server/main.go
+++ b/backend/cmd/server/main.go
@@ -92,6 +92,7 @@ func main() {
 	mux.HandleFunc("/api/admin/agencies/register", agencyHandler.RegisterAgency)
 	mux.HandleFunc("/api/admin/agencies", tenantHandler.ListAll)
 	mux.HandleFunc("/api/admin/agencies/", agencyHandler.HandleAgency)
+	mux.HandleFunc("/api/tenant/check", tenantHandler.CheckExists)
 
 	// Client registration (ADMIN_AGENCIA only - requires auth)
 	mux.Handle("/api/agencies/clients/register", authMiddleware(http.HandlerFunc(agencyHandler.RegisterClient)))
diff --git a/backend/internal/api/handlers/tenant.go b/backend/internal/api/handlers/tenant.go
index 2c60c56..45327ed 100644
--- a/backend/internal/api/handlers/tenant.go
+++ b/backend/internal/api/handlers/tenant.go
@@ -40,3 +40,31 @@ func (h *TenantHandler) ListAll(w http.ResponseWriter, r *http.Request) {
 	w.Header().Set("Content-Type", "application/json; charset=utf-8")
 	json.NewEncoder(w).Encode(tenants)
 }
+
+// CheckExists returns 200 if tenant exists by subdomain, otherwise 404
+func (h *TenantHandler) CheckExists(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodGet {
+		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
+		return
+	}
+
+	subdomain := r.URL.Query().Get("subdomain")
+	if subdomain == "" {
+		http.Error(w, "subdomain is required", http.StatusBadRequest)
+		return
+	}
+
+	tenant, err := h.tenantService.GetBySubdomain(subdomain)
+	if err != nil {
+		http.Error(w, "Internal server error", http.StatusInternalServerError)
+		return
+	}
+
+	if tenant == nil {
+		http.NotFound(w, r)
+		return
+	}
+
+	w.Header().Set("Content-Type", "application/json; charset=utf-8")
+	json.NewEncoder(w).Encode(map[string]string{"status": "ok"})
+}
diff --git a/backend/internal/service/tenant_service.go b/backend/internal/service/tenant_service.go
index b3d971e..f3a4d02 100644
--- a/backend/internal/service/tenant_service.go
+++ b/backend/internal/service/tenant_service.go
@@ -79,6 +79,11 @@ func (s *TenantService) ListAll() ([]*domain.Tenant, error) {
 	return s.tenantRepo.FindAll()
 }
 
+// GetBySubdomain returns tenant by subdomain or nil
+func (s *TenantService) GetBySubdomain(subdomain string) (*domain.Tenant, error) {
+	return s.tenantRepo.FindBySubdomain(subdomain)
+}
+
 // Delete removes a tenant by ID
 func (s *TenantService) Delete(id uuid.UUID) error {
 	if err := s.tenantRepo.Delete(id); err != nil {
diff --git a/front-end-dash.aggios.app/middleware.ts b/front-end-dash.aggios.app/middleware.ts
index e636880..2fd70b6 100644
--- a/front-end-dash.aggios.app/middleware.ts
+++ b/front-end-dash.aggios.app/middleware.ts
@@ -14,7 +14,23 @@ export function middleware(request: NextRequest) {
         return NextResponse.next();
     }
 
-    // Se for agência ({subdomain}.localhost) - rotas de tenant
+    // Se for agência ({subdomain}.localhost) - validar se existe
+    if (hostname.includes('.')) {
+        try {
+            const res = await fetch(`http://backend:8080/api/tenant/check?subdomain=${subdomain}`);
+            if (res.status === 404) {
+                // Redireciona para o host base (sem subdomínio)
+                const baseHost = hostname.split('.').slice(1).join('.') || hostname;
+                const redirectUrl = new URL(url.toString());
+                redirectUrl.hostname = baseHost;
+                redirectUrl.pathname = '/';
+                return NextResponse.redirect(redirectUrl);
+            }
+        } catch (err) {
+            // Em caso de erro de rede, não bloquear
+        }
+    }
+
     // Permitir /dashboard, /login, /clientes, etc.
     return NextResponse.next();
 }