// limitations under the License.

package xds

import (
	"context"
	"fmt"
	"sort"
	"strconv"
	"sync"
	"time"

	discovery "github.com/envoyproxy/go-control-plane/envoy/service/discovery/v3"
	"github.com/google/uuid"
	"go.uber.org/atomic"
	"golang.org/x/time/rate"
	"google.golang.org/grpc"

	"istio.io/istio/pilot/pkg/autoregistration"

	"istio.io/istio/pkg/log"
	"istio.io/istio/pkg/maps"
	"istio.io/istio/pkg/slices"
	"istio.io/istio/pkg/util/sets"
	"istio.io/istio/pkg/workloadapi"
)

// ServiceDiscovery is a mock discovery interface
type ServiceDiscovery struct {
	services map[host.Name]*model.Service

	handlers model.ControllerHandlers

	networkGateways []model.NetworkGateway
	model.NetworkGatewaysHandler

		ClusterID:           "cluster-1",
		DiscoveryController: discovery1,
	}

	registry2 := serviceregistry.Simple{
		ProviderID:          provider.Kubernetes,
		ClusterID:           "cluster-2",
		DiscoveryController: discovery2,
	}

	ctls := NewController(Options{})
	ctls.AddRegistry(registry1)
	ctls.AddRegistry(registry2)

	return ctls, discovery1, discovery2
}

func TestServicesForMultiCluster(t *testing.T) {

		fakeclient := apiclient.NewDryRunClientWithOpts(dryRunOpts)
		// As we know the return of Discovery() of the fake clientset is of type *fakediscovery.FakeDiscovery
		// we can convert it to that struct.
		fakeclientDiscovery, ok := fakeclient.Discovery().(*fakediscovery.FakeDiscovery)
		if !ok {
			return nil, errors.New("couldn't set fake discovery's server version")
		}
		// Lastly, set the right server version to be used

						Hints: &discovery.EndpointHints{
							ForZones: []discovery.ForZone{{Name: "zone-a-old"}},
						},
					},
					{
						Hints: &discovery.EndpointHints{
							ForZones: []discovery.ForZone{{Name: "zone-b-old"}},
						},
					},
				},
			},
			newEPS: &discovery.EndpointSlice{
				Endpoints: []discovery.Endpoint{
					{
						Hints: &discovery.EndpointHints{

		oldEndpointSlice    *discovery.EndpointSlice
		newEndpointSlice    *discovery.EndpointSlice
	}{
		"valid and identical slices": {
			oldEndpointSlice: &discovery.EndpointSlice{
				ObjectMeta:  standardMeta,
				AddressType: discovery.AddressTypeIPv6,
			},
			newEndpointSlice: &discovery.EndpointSlice{
				ObjectMeta:  standardMeta,
				AddressType: discovery.AddressTypeIPv6,
			},

			initialSlice: &discovery.EndpointSlice{
				ObjectMeta: objMeta,
				Ports:      []discovery.EndpointPort{port443},
				Endpoints:  []discovery.Endpoint{endpoint1, endpoint2},
			},
			updatedSlice: &discovery.EndpointSlice{
				ObjectMeta: objMeta,
				Ports:      []discovery.EndpointPort{port443},
				Endpoints:  []discovery.Endpoint{endpoint1, endpoint2},
			},
			expectChanged: false,

		}),
	)
	populateEndpointSlices(proxier,
		makeTestEndpointSlice(svcPortName.Namespace, svcPortName.Name, 1, func(eps *discovery.EndpointSlice) {
			eps.AddressType = discovery.AddressTypeIPv4
			eps.Endpoints = []discovery.Endpoint{{
				Addresses: []string{epIpAddressRemote},
			}}
			eps.Ports = []discovery.EndpointPort{{
				Name:     ptr.To(svcPortName.Port),
				Port:     ptr.To(int32(svcPort)),

	p.connectedMutex.Unlock()
}

func (p *XdsProxy) forwardDeltaToTap(resp *discovery.DeltaDiscoveryResponse) {
	select {
	// Convert back to a SotW response
	case p.tapResponseChannel <- &discovery.DiscoveryResponse{
		VersionInfo:  resp.SystemVersionInfo,
		Resources:    slices.Map(resp.Resources, (*discovery.Resource).GetResource),
		Canary:       false,
		TypeUrl:      resp.TypeUrl,

					return nil, err
				}
				return map[string]*discovery.DiscoveryResponse{
					CpInfo(response).ID: response,
				}, nil
			}
		}
		return nil, err
	}
	return mapShards(responses)
}

func mapShards(responses []*discovery.DiscoveryResponse) (map[string]*discovery.DiscoveryResponse, error) {
	retval := map[string]*discovery.DiscoveryResponse{}

	for _, response := range responses {