package helper

import (
	"fmt"

	apierrors "k8s.io/apimachinery/pkg/api/errors"
	"k8s.io/apimachinery/pkg/api/meta"
	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
	"k8s.io/apimachinery/pkg/runtime"
	"k8s.io/klog/v2"

	"github.com/karmada-io/karmada/pkg/util/informermanager"
	"github.com/karmada-io/karmada/pkg/util/informermanager/keys"
	"github.com/karmada-io/karmada/pkg/util/restmapper"
)

// GetObjectFromCache gets full object information from cache by key in worker queue.
func GetObjectFromCache(restMapper meta.RESTMapper, manager informermanager.MultiClusterInformerManager,
	fedKey keys.FederatedKey) (*unstructured.Unstructured, error) {
	gvr, err := restmapper.GetGroupVersionResource(restMapper, fedKey.GroupVersionKind())
	if err != nil {
		klog.Errorf("Failed to get GVR from GVK %s. Error: %v", fedKey.GroupVersionKind(), err)
		return nil, err
	}

	singleClusterManager := manager.GetSingleClusterManager(fedKey.Cluster)
	if singleClusterManager == nil {
		// That may happen in case of multi-controllers sharing one informer. For example:
		// controller-A takes responsibility of initialize informer for clusters, but controller-B consumes
		// the informer before the initialization.
		// Usually this error will be eliminated during the controller reconciling loop.
		return nil, fmt.Errorf("the informer of cluster(%s) has not been initialized", fedKey.Cluster)
	}
	var obj runtime.Object
	lister := singleClusterManager.Lister(gvr)
	obj, err = lister.Get(fedKey.NamespaceKey())
	if err != nil {
		if apierrors.IsNotFound(err) {
			return nil, err
		}

		// print logs only for real error.
		klog.Errorf("Failed to get obj %s. error: %v.", fedKey.String(), err)

		return nil, err
	}
	return obj.(*unstructured.Unstructured), nil
}