// Package router — NSWatcher for multi-tenant mode.
//
// Listens for Namespaces labeled fission.io/managed=true and calls
// HTTPTriggerSet.AddNamespace so the router picks up HTTPTriggers and
// Functions in tenant namespaces without a restart.
package router

import (
	"context"

	"go.uber.org/zap"
	"k8s.io/client-go/kubernetes"

	"github.com/fission/fission/pkg/utils"
	"github.com/fission/fission/pkg/utils/manager"
)

// StartNSWatcher registers a Kubernetes Namespace Informer for the router.
// Whenever a Namespace with label fission.io/managed=true appears (or is relabeled),
// the router immediately subscribes to HTTPTriggers and Functions in that namespace.
func StartNSWatcher(
	ctx context.Context,
	logger *zap.Logger,
	kubeClient kubernetes.Interface,
	ts *HTTPTriggerSet,
	mgr manager.Interface,
) {
	_, handlers, err := utils.PrepareManagedNamespaceWatcher(ctx, logger, "router.NSWatcher", utils.DefaultNSResolver().Snapshot(), utils.NamespaceRemovalStrategyTrackOnly, NewNamespaceSubscriber(ts, mgr))
	if err != nil {
		logger.Error("router.NSWatcher: BootstrapAndDispatch failed", zap.Error(err))
	}
	utils.StartManagedNamespaceWatcher(ctx, logger, "router.NSWatcher", kubeClient, mgr, handlers)
}