package servicemirror

import (
	"context"
	"fmt"
	"log"
	"strings"

	"github.com/go-test/deep"
	"github.com/linkerd/linkerd2/controller/gen/apis/link/v1alpha3"
	"github.com/linkerd/linkerd2/controller/k8s"
	consts "github.com/linkerd/linkerd2/pkg/k8s"
	logging "github.com/sirupsen/logrus"
	corev1 "k8s.io/api/core/v1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/client-go/util/workqueue"
	"sigs.k8s.io/yaml"
)

const (
	clusterName        = "remote"
	clusterDomain      = "cluster.local"
	defaultProbePath   = "/probe"
	defaultProbePort   = 12345
	defaultProbePeriod = "60"
)

var (
	defaultProbeSpec = v1alpha3.ProbeSpec{
		Path:   defaultProbePath,
		Port:   fmt.Sprintf("%d", defaultProbePort),
		Period: defaultProbePeriod,
	}
	defaultSelector, _                = metav1.ParseToLabelSelector(consts.DefaultExportedServiceSelector + "=true")
	defaultRemoteDiscoverySelector, _ = metav1.ParseToLabelSelector(consts.DefaultExportedServiceSelector + "=remote-discovery")
)

type testEnvironment struct {
	events          []interface{}
	remoteResources []string
	localResources  []string
	link            v1alpha3.Link
}

func (te *testEnvironment) runEnvironment(watcherQueue workqueue.TypedRateLimitingInterface[any]) (*k8s.API, error) {
	remoteAPI, err := k8s.NewFakeAPI(te.remoteResources...)
	if err != nil {
		return nil, err
	}
	localAPI, err := k8s.NewFakeAPIWithL5dClient(te.localResources...)
	if err != nil {
		return nil, err
	}
	linksAPI := k8s.NewNamespacedAPI(nil, nil, localAPI.L5dClient, "default", "local", k8s.Link)
	remoteAPI.Sync(nil)
	localAPI.Sync(nil)
	linksAPI.Sync(nil)

	watcher := RemoteClusterServiceWatcher{
		link:                    &te.link,
		remoteAPIClient:         remoteAPI,
		localAPIClient:          localAPI,
		linksAPIClient:          linksAPI,
		stopper:                 nil,
		log:                     logging.WithFields(logging.Fields{"cluster": clusterName}),
		eventsQueue:             watcherQueue,
		requeueLimit:            0,
		gatewayAlive:            true,
		headlessServicesEnabled: true,
	}

	for _, ev := range te.events {
		watcherQueue.Add(ev)
	}

	for range te.events {
		watcher.processNextEvent(context.Background())
	}

	localAPI.Sync(nil)
	remoteAPI.Sync(nil)

	return localAPI, nil
}

var createExportedService = &testEnvironment{
	events: []interface{}{
		&RemoteServiceExported{
			service: remoteService("service-one", "ns1", "111", map[string]string{
				consts.DefaultExportedServiceSelector: "true",
				"lk":                                  "lv",
			}, []corev1.ServicePort{
				{
					Name:     "port1",
					Protocol: "TCP",
					Port:     555,
				},
				{
					Name:     "port2",
					Protocol: "TCP",
					Port:     666,
				},
			}),
		},
	},
	remoteResources: []string{
		asYaml(gateway("existing-gateway", "existing-namespace", "222", "192.0.2.127", "mc-gateway", 888, "gateway-identity", defaultProbePort, defaultProbePath, defaultProbePeriod)),
		asYaml(endpoints("service-one", "ns1", nil, "192.0.2.127", "gateway-identity", []corev1.EndpointPort{})),
	},
	localResources: []string{
		asYaml(namespace("ns1")),
	},
	link: v1alpha3.Link{
		Spec: v1alpha3.LinkSpec{
			TargetClusterName:       clusterName,
			TargetClusterDomain:     clusterDomain,
			GatewayIdentity:         "gateway-identity",
			GatewayAddress:          "192.0.2.127",
			GatewayPort:             "888",
			ProbeSpec:               defaultProbeSpec,
			Selector:                defaultSelector,
			RemoteDiscoverySelector: defaultRemoteDiscoverySelector,
		},
	},
}

var createRemoteDiscoveryService = &testEnvironment{
	events: []interface{}{
		&RemoteServiceExported{
			service: remoteService("service-one", "ns1", "111", map[string]string{
				consts.DefaultExportedServiceSelector: "remote-discovery",
			}, []corev1.ServicePort{
				{
					Name:     "port1",
					Protocol: "TCP",
					Port:     555,
				},
				{
					Name:     "port2",
					Protocol: "TCP",
					Port:     666,
				},
			}),
		},
	},
	remoteResources: []string{
		asYaml(endpoints("service-one", "ns1", nil, "192.0.2.127", "gateway-identity", []corev1.EndpointPort{})),
	},
	localResources: []string{
		asYaml(namespace("ns1")),
	},
	link: v1alpha3.Link{
		Spec: v1alpha3.LinkSpec{
			TargetClusterName:       clusterName,
			TargetClusterDomain:     clusterDomain,
			GatewayIdentity:         "gateway-identity",
			GatewayAddress:          "192.0.2.127",
			GatewayPort:             "888",
			ProbeSpec:               defaultProbeSpec,
			Selector:                defaultSelector,
			RemoteDiscoverySelector: defaultRemoteDiscoverySelector,
		},
	},
}

var createFederatedService = &testEnvironment{
	events: []interface{}{
		&CreateFederatedService{
			service: remoteService("service-one", "ns1", "111", map[string]string{
				consts.DefaultFederatedServiceSelector: "member",
			}, []corev1.ServicePort{
				{
					Name:     "port1",
					Protocol: "TCP",
					Port:     555,
				},
				{
					Name:     "port2",
					Protocol: "TCP",
					Port:     666,
				},
			}),
		},
	},
	remoteResources: []string{
		asYaml(endpoints("service-one", "ns1", nil, "192.0.2.127", "gateway-identity", []corev1.EndpointPort{})),
	},
	localResources: []string{
		asYaml(namespace("ns1")),
	},
	link: v1alpha3.Link{
		Spec: v1alpha3.LinkSpec{
			TargetClusterName:       clusterName,
			TargetClusterDomain:     clusterDomain,
			GatewayIdentity:         "gateway-identity",
			GatewayAddress:          "192.0.2.127",
			GatewayPort:             "888",
			ProbeSpec:               defaultProbeSpec,
			Selector:                defaultSelector,
			RemoteDiscoverySelector: defaultRemoteDiscoverySelector,
		},
	},
}

func joinFederatedService() *testEnvironment {
	fedSvc := federatedService("service-one", "ns1", []corev1.ServicePort{
		{
			Name:     "port1",
			Protocol: "TCP",
			Port:     555,
		},
		{
			Name:     "port2",
			Protocol: "TCP",
			Port:     666,
		},
	}, "", "service-one@other")
	return &testEnvironment{
		events: []interface{}{
			&RemoteServiceJoinsFederatedService{
				remoteUpdate: remoteService("service-one", "ns1", "111", map[string]string{
					consts.DefaultFederatedServiceSelector: "member",
				}, []corev1.ServicePort{
					{
						Name:     "port1",
						Protocol: "TCP",
						Port:     555,
					},
					{
						Name:     "port2",
						Protocol: "TCP",
						Port:     666,
					},
				}),
			},
		},
		remoteResources: []string{
			asYaml(endpoints("service-one", "ns1", nil, "192.0.2.127", "gateway-identity", []corev1.EndpointPort{})),
		},
		localResources: []string{
			asYaml(namespace("ns1")),
			asYaml(fedSvc),
		},
		link: v1alpha3.Link{
			Spec: v1alpha3.LinkSpec{
				TargetClusterName:       clusterName,
				TargetClusterDomain:     clusterDomain,
				GatewayIdentity:         "gateway-identity",
				GatewayAddress:          "192.0.2.127",
				GatewayPort:             "888",
				ProbeSpec:               defaultProbeSpec,
				Selector:                defaultSelector,
				RemoteDiscoverySelector: defaultRemoteDiscoverySelector,
			},
		},
	}
}

var leftFederatedService = &testEnvironment{
	events: []interface{}{
		&RemoteServiceLeavesFederatedService{
			Name:      "service-one",
			Namespace: "ns1",
		},
	},
	remoteResources: []string{
		asYaml(endpoints("service-one", "ns1", nil, "192.0.2.127", "gateway-identity", []corev1.EndpointPort{})),
	},
	localResources: []string{
		asYaml(namespace("ns1")),
		asYaml(federatedService("service-one", "ns1", []corev1.ServicePort{
			{
				Name:     "port1",
				Protocol: "TCP",
				Port:     555,
			},
			{
				Name:     "port2",
				Protocol: "TCP",
				Port:     666,
			},
		}, "", fmt.Sprintf("service-one@other,service-one@%s", clusterName))),
	},
	link: v1alpha3.Link{
		Spec: v1alpha3.LinkSpec{
			TargetClusterName:       clusterName,
			TargetClusterDomain:     clusterDomain,
			GatewayIdentity:         "gateway-identity",
			GatewayAddress:          "192.0.2.127",
			GatewayPort:             "888",
			ProbeSpec:               defaultProbeSpec,
			Selector:                defaultSelector,
			RemoteDiscoverySelector: defaultRemoteDiscoverySelector,
		},
	},
}

var createLocalFederatedService = &testEnvironment{
	events: []interface{}{
		&CreateFederatedService{
			service: remoteService("service-one", "ns1", "111", map[string]string{
				consts.DefaultFederatedServiceSelector: "member",
			}, []corev1.ServicePort{
				{
					Name:     "port1",
					Protocol: "TCP",
					Port:     555,
				},
				{
					Name:     "port2",
					Protocol: "TCP",
					Port:     666,
				},
			}),
		},
	},
	remoteResources: []string{
		asYaml(endpoints("service-one", "ns1", nil, "192.0.2.127", "gateway-identity", []corev1.EndpointPort{})),
	},
	localResources: []string{
		asYaml(namespace("ns1")),
	},
	link: v1alpha3.Link{
		Spec: v1alpha3.LinkSpec{
			TargetClusterName:       "", // local cluster
			TargetClusterDomain:     clusterDomain,
			GatewayIdentity:         "gateway-identity",
			GatewayAddress:          "192.0.2.127",
			GatewayPort:             "888",
			ProbeSpec:               defaultProbeSpec,
			Selector:                defaultSelector,
			RemoteDiscoverySelector: defaultRemoteDiscoverySelector,
		},
	},
}

func joinLocalFederatedService() *testEnvironment {
	fedSvc := federatedService("service-one", "ns1", []corev1.ServicePort{
		{
			Name:     "port1",
			Protocol: "TCP",
			Port:     555,
		},
		{
			Name:     "port2",
			Protocol: "TCP",
			Port:     666,
		},
	}, "", "service-one@other")
	return &testEnvironment{
		events: []interface{}{
			&RemoteServiceJoinsFederatedService{
				remoteUpdate: remoteService("service-one", "ns1", "111", map[string]string{
					consts.DefaultFederatedServiceSelector: "member",
				}, []corev1.ServicePort{
					{
						Name:     "port1",
						Protocol: "TCP",
						Port:     555,
					},
					{
						Name:     "port2",
						Protocol: "TCP",
						Port:     666,
					},
				}),
			},
		},
		remoteResources: []string{
			asYaml(endpoints("service-one", "ns1", nil, "192.0.2.127", "gateway-identity", []corev1.EndpointPort{})),
		},
		localResources: []string{
			asYaml(namespace("ns1")),
			asYaml(fedSvc),
		},
		link: v1alpha3.Link{
			Spec: v1alpha3.LinkSpec{
				TargetClusterName:       "", // local cluster
				TargetClusterDomain:     clusterDomain,
				GatewayIdentity:         "gateway-identity",
				GatewayAddress:          "192.0.2.127",
				GatewayPort:             "888",
				ProbeSpec:               defaultProbeSpec,
				Selector:                defaultSelector,
				RemoteDiscoverySelector: defaultRemoteDiscoverySelector,
			},
		},
	}
}

var leftLocalFederatedService = &testEnvironment{
	events: []interface{}{
		&RemoteServiceLeavesFederatedService{
			Name:      "service-one",
			Namespace: "ns1",
		},
	},
	remoteResources: []string{
		asYaml(endpoints("service-one", "ns1", nil, "192.0.2.127", "gateway-identity", []corev1.EndpointPort{})),
	},
	localResources: []string{
		asYaml(namespace("ns1")),
		asYaml(federatedService("service-one", "ns1", []corev1.ServicePort{
			{
				Name:     "port1",
				Protocol: "TCP",
				Port:     555,
			},
			{
				Name:     "port2",
				Protocol: "TCP",
				Port:     666,
			},
		}, "service-one", "service-one@other")),
	},
	link: v1alpha3.Link{
		Spec: v1alpha3.LinkSpec{
			TargetClusterName:       "", // local cluster
			TargetClusterDomain:     clusterDomain,
			GatewayIdentity:         "gateway-identity",
			GatewayAddress:          "192.0.2.127",
			GatewayPort:             "888",
			ProbeSpec:               defaultProbeSpec,
			Selector:                defaultSelector,
			RemoteDiscoverySelector: defaultRemoteDiscoverySelector,
		},
	},
}

var createExportedHeadlessService = &testEnvironment{
	events: []interface{}{
		&RemoteServiceExported{
			service: remoteHeadlessService("service-one", "ns2", "111", map[string]string{
				consts.DefaultExportedServiceSelector: "true",
				"lk":                                  "lv",
			}, []corev1.ServicePort{
				{
					Name:     "port1",
					Protocol: "TCP",
					Port:     555,
				},
				{
					Name:     "port2",
					Protocol: "TCP",
					Port:     666,
				},
			}),
		},
		&OnAddEndpointsCalled{
			ep: remoteHeadlessEndpoints("service-one", "ns2", "112", "192.0.0.1", []corev1.EndpointPort{
				{
					Name:     "port1",
					Protocol: "TCP",
					Port:     555,
				},
				{
					Name:     "port2",
					Protocol: "TCP",
					Port:     666,
				},
			}),
		},
	},
	remoteResources: []string{
		asYaml(gateway("existing-gateway", "existing-namespace", "222", "192.0.2.129", "gateway", 889, "gateway-identity", 123456, "/probe1", "120s")),
		asYaml(remoteHeadlessService("service-one", "ns2", "111", map[string]string{"lk": "lv"},
			[]corev1.ServicePort{
				{
					Name:     "port1",
					Protocol: "TCP",
					Port:     555,
				},
				{
					Name:     "port2",
					Protocol: "TCP",
					Port:     666,
				},
			})),
		asYaml(remoteHeadlessEndpoints("service-one", "ns2", "112", "192.0.0.1", []corev1.EndpointPort{
			{
				Name:     "port1",
				Protocol: "TCP",
				Port:     555,
			},
			{
				Name:     "port2",
				Protocol: "TCP",
				Port:     666,
			},
		})),
	},
	localResources: []string{
		asYaml(namespace("ns2")),
	},
	link: v1alpha3.Link{
		Spec: v1alpha3.LinkSpec{
			TargetClusterName:   clusterName,
			TargetClusterDomain: clusterDomain,
			GatewayIdentity:     "gateway-identity",
			GatewayAddress:      "192.0.2.129",
			GatewayPort:         "889",
			ProbeSpec: v1alpha3.ProbeSpec{
				Port:   "123456",
				Path:   "/probe1",
				Period: "120",
			},
			Selector:                defaultSelector,
			RemoteDiscoverySelector: defaultRemoteDiscoverySelector,
		},
	},
}

var deleteMirrorService = &testEnvironment{
	events: []interface{}{
		&RemoteServiceUnexported{
			Name:      "test-service-remote-to-delete",
			Namespace: "test-namespace-to-delete",
		},
	},
	localResources: []string{
		asYaml(mirrorService("test-service-remote-to-delete-remote", "test-namespace-to-delete", "", nil, nil)),
		asYaml(endpoints("test-service-remote-to-delete-remote", "test-namespace-to-delete", nil, "", "gateway-identity", nil)),
	},
	link: v1alpha3.Link{
		Spec: v1alpha3.LinkSpec{
			TargetClusterName:       clusterName,
			TargetClusterDomain:     clusterDomain,
			GatewayIdentity:         "gateway-identity",
			GatewayAddress:          "192.0.2.127",
			GatewayPort:             "888",
			ProbeSpec:               defaultProbeSpec,
			Selector:                defaultSelector,
			RemoteDiscoverySelector: defaultRemoteDiscoverySelector,
		},
	},
}

var updateServiceWithChangedPorts = &testEnvironment{
	events: []interface{}{
		&RemoteExportedServiceUpdated{
			remoteUpdate: remoteService("test-service", "test-namespace", "currentServiceResVersion", map[string]string{
				consts.DefaultExportedServiceSelector: "true",
			}, []corev1.ServicePort{
				{
					Name:     "port1",
					Protocol: "TCP",
					Port:     111,
				},
				{
					Name:     "port3",
					Protocol: "TCP",
					Port:     333,
				},
			}),
		},
	},
	remoteResources: []string{
		asYaml(gateway("gateway", "gateway-ns", "currentGatewayResVersion", "192.0.2.127", "mc-gateway", 888, "", defaultProbePort, defaultProbePath, defaultProbePeriod)),
	},
	localResources: []string{
		asYaml(mirrorService("test-service-remote", "test-namespace", "past", nil, []corev1.ServicePort{
			{
				Name:     "port1",
				Protocol: "TCP",
				Port:     111,
			},
			{
				Name:     "port2",
				Protocol: "TCP",
				Port:     222,
			},
			{
				Name:     "port3",
				Protocol: "TCP",
				Port:     333,
			},
		})),
		asYaml(endpoints("test-service-remote", "test-namespace", nil, "192.0.2.127", "", []corev1.EndpointPort{
			{
				Name:     "port1",
				Port:     888,
				Protocol: "TCP",
			},
			{
				Name:     "port2",
				Port:     888,
				Protocol: "TCP",
			},
			{
				Name:     "port3",
				Port:     888,
				Protocol: "TCP",
			},
		})),
	},
	link: v1alpha3.Link{
		Spec: v1alpha3.LinkSpec{
			TargetClusterName:       clusterName,
			TargetClusterDomain:     clusterDomain,
			GatewayIdentity:         "gateway-identity",
			GatewayAddress:          "192.0.2.127",
			GatewayPort:             "888",
			ProbeSpec:               defaultProbeSpec,
			Selector:                defaultSelector,
			RemoteDiscoverySelector: defaultRemoteDiscoverySelector,
		},
	},
}

var updateEndpointsWithChangedHosts = &testEnvironment{
	events: []interface{}{
		&OnUpdateEndpointsCalled{
			ep: remoteHeadlessEndpointsUpdate("service-two", "eptest", "112", "192.0.0.1", []corev1.EndpointPort{
				{
					Name:     "port1",
					Protocol: "TCP",
					Port:     555,
				},
				{
					Name:     "port2",
					Protocol: "TCP",
					Port:     666,
				},
			}),
		},
	},
	remoteResources: []string{
		asYaml(gateway("gateway", "gateway-ns", "currentGatewayResVersion", "192.0.2.127", "mc-gateway", 888, "", defaultProbePort, defaultProbePath, defaultProbePeriod)),
		asYaml(remoteHeadlessService("service-two", "eptest", "222", nil,
			[]corev1.ServicePort{
				{
					Name:     "port1",
					Protocol: "TCP",
					Port:     555,
				},
				{

					Name:     "port2",
					Protocol: "TCP",
					Port:     666,
				},
			})),
	},
	localResources: []string{
		asYaml(headlessMirrorService("service-two-remote", "eptest", "222", nil,
			[]corev1.ServicePort{
				{
					Name:     "port1",
					Protocol: "TCP",
					Port:     555,
				},
				{
					Name:     "port2",
					Protocol: "TCP",
					Port:     666,
				},
			})),
		asYaml(endpointMirrorService("pod-0", "service-two-remote", "eptest", "333", nil, []corev1.ServicePort{
			{
				Name:     "port1",
				Protocol: "TCP",
				Port:     555,
			},
			{
				Name:     "port2",
				Protocol: "TCP",
				Port:     666,
			},
		})),
		asYaml(headlessMirrorEndpoints(
			"service-two-remote",
			"eptest",
			nil,
			"gateway-identity",
			[]corev1.EndpointPort{
				{
					Name:     "port1",
					Protocol: "TCP",
					Port:     555,
				},
				{
					Name:     "port2",
					Protocol: "TCP",
					Port:     666,
				},
			})),
		asYaml(endpointMirrorEndpoints(
			"service-two-remote",
			"eptest",
			nil,
			"pod-0",
			"192.0.2.127",
			"gateway-identity",
			[]corev1.EndpointPort{
				{
					Name:     "port1",
					Protocol: "TCP",
					Port:     888,
				},
				{
					Name:     "port2",
					Protocol: "TCP",
					Port:     888,
				},
			})),
	},
	link: v1alpha3.Link{
		Spec: v1alpha3.LinkSpec{
			TargetClusterName:       clusterName,
			TargetClusterDomain:     clusterDomain,
			GatewayIdentity:         "gateway-identity",
			GatewayAddress:          "192.0.2.127",
			GatewayPort:             "888",
			ProbeSpec:               defaultProbeSpec,
			Selector:                defaultSelector,
			RemoteDiscoverySelector: defaultRemoteDiscoverySelector,
		},
	},
}
var clusterUnregistered = &testEnvironment{
	events: []interface{}{
		&ClusterUnregistered{},
	},
	localResources: []string{
		asYaml(mirrorService("test-service-1-remote", "test-namespace", "", nil, nil)),
		asYaml(endpoints("test-service-1-remote", "test-namespace", nil, "", "", nil)),
		asYaml(mirrorService("test-service-2-remote", "test-namespace", "", nil, nil)),
		asYaml(endpoints("test-service-2-remote", "test-namespace", nil, "", "", nil)),
	},
	link: v1alpha3.Link{
		Spec: v1alpha3.LinkSpec{
			TargetClusterName: clusterName,
		},
	},
}

var gcTriggered = &testEnvironment{
	events: []interface{}{
		&OrphanedServicesGcTriggered{},
	},
	localResources: []string{
		asYaml(mirrorService("test-service-1-remote", "test-namespace", "", nil, nil)),
		asYaml(endpoints("test-service-1-remote", "test-namespace", nil, "", "", nil)),
		asYaml(mirrorService("test-service-2-remote", "test-namespace", "", nil, nil)),
		asYaml(endpoints("test-service-2-remote", "test-namespace", nil, "", "", nil)),
		asYaml(headlessMirrorService("test-headless-service-remote", "test-namespace", "", nil, nil)),
		asYaml(endpointMirrorService("pod-0", "test-headless-service-remote", "test-namespace", "", nil, nil)),
		asYaml(headlessMirrorEndpoints("test-headless-service-remote", "test-namespace", nil, "", nil)),
		asYaml(endpointMirrorEndpoints("test-headless-service-remote", "test-namespace", nil, "pod-0", "", "", nil)),
	},
	remoteResources: []string{
		asYaml(remoteService("test-service-1", "test-namespace", "", map[string]string{consts.DefaultExportedServiceSelector: "true"}, nil)),
		asYaml(remoteHeadlessService("test-headless-service", "test-namespace", "", nil, nil)),
	},
	link: v1alpha3.Link{
		Spec: v1alpha3.LinkSpec{
			TargetClusterName: clusterName,
		},
	},
}

var noGatewayLink = &testEnvironment{
	events: []interface{}{
		&RemoteServiceExported{
			service: remoteService("service-one", "ns1", "111", map[string]string{
				consts.DefaultExportedServiceSelector: "remote-discovery",
			}, []corev1.ServicePort{
				{
					Name:     "port1",
					Protocol: "TCP",
					Port:     555,
				},
				{
					Name:     "port2",
					Protocol: "TCP",
					Port:     666,
				},
			}),
		},
		&RemoteServiceExported{
			service: remoteService("service-two", "ns1", "111", map[string]string{
				consts.DefaultExportedServiceSelector: "true",
			}, []corev1.ServicePort{
				{
					Name:     "port1",
					Protocol: "TCP",
					Port:     555,
				},
				{
					Name:     "port2",
					Protocol: "TCP",
					Port:     666,
				},
			}),
		},
	},
	localResources: []string{
		asYaml(namespace("ns1")),
	},
	remoteResources: []string{
		asYaml(endpoints("service-one", "ns1", nil, "192.0.2.127", "gateway-identity", []corev1.EndpointPort{})),
		asYaml(endpoints("service-two", "ns1", nil, "192.0.2.128", "gateway-identity", []corev1.EndpointPort{})),
	},
	link: v1alpha3.Link{
		Spec: v1alpha3.LinkSpec{
			TargetClusterName:       clusterName,
			TargetClusterDomain:     clusterDomain,
			Selector:                &metav1.LabelSelector{},
			RemoteDiscoverySelector: defaultRemoteDiscoverySelector,
		},
	},
}

func onAddOrUpdateExportedSvc(isAdd bool) *testEnvironment {
	return &testEnvironment{
		events: []interface{}{
			onAddOrUpdateEvent(isAdd, remoteService("test-service", "test-namespace", "resVersion", map[string]string{
				consts.DefaultExportedServiceSelector: "true",
			}, nil)),
		},
		link: v1alpha3.Link{
			Spec: v1alpha3.LinkSpec{
				TargetClusterName:       clusterName,
				TargetClusterDomain:     clusterDomain,
				GatewayIdentity:         "gateway-identity",
				GatewayAddress:          "192.0.2.127",
				GatewayPort:             "888",
				ProbeSpec:               defaultProbeSpec,
				Selector:                defaultSelector,
				RemoteDiscoverySelector: defaultRemoteDiscoverySelector,
			},
		},
	}

}

func onAddOrUpdateRemoteServiceUpdated(isAdd bool) *testEnvironment {
	return &testEnvironment{
		events: []interface{}{
			onAddOrUpdateEvent(isAdd, remoteService("test-service", "test-namespace", "currentResVersion", map[string]string{
				consts.DefaultExportedServiceSelector: "true",
			}, nil)),
		},
		localResources: []string{
			asYaml(mirrorService("test-service-remote", "test-namespace", "pastResourceVersion", nil, nil)),
			asYaml(endpoints("test-service-remote", "test-namespace", nil, "0.0.0.0", "", nil)),
		},
		link: v1alpha3.Link{
			Spec: v1alpha3.LinkSpec{
				TargetClusterName:       clusterName,
				TargetClusterDomain:     clusterDomain,
				GatewayIdentity:         "gateway-identity",
				GatewayAddress:          "192.0.2.127",
				GatewayPort:             "888",
				ProbeSpec:               defaultProbeSpec,
				Selector:                defaultSelector,
				RemoteDiscoverySelector: defaultRemoteDiscoverySelector,
			},
		},
	}
}

func onAddOrUpdateSameResVersion(isAdd bool) *testEnvironment {
	return &testEnvironment{
		events: []interface{}{
			onAddOrUpdateEvent(isAdd, remoteService("test-service", "test-namespace", "currentResVersion", map[string]string{
				consts.DefaultExportedServiceSelector: "true",
			}, nil)),
		},
		localResources: []string{
			asYaml(mirrorService("test-service-remote", "test-namespace", "currentResVersion", nil, nil)),
			asYaml(endpoints("test-service-remote", "test-namespace", nil, "0.0.0.0", "", nil)),
		},
		link: v1alpha3.Link{
			Spec: v1alpha3.LinkSpec{
				TargetClusterName:       clusterName,
				TargetClusterDomain:     clusterDomain,
				GatewayIdentity:         "gateway-identity",
				GatewayAddress:          "192.0.2.127",
				GatewayPort:             "888",
				ProbeSpec:               defaultProbeSpec,
				Selector:                defaultSelector,
				RemoteDiscoverySelector: defaultRemoteDiscoverySelector,
			},
		},
	}
}

func serviceNotExportedAnymore(isAdd bool) *testEnvironment {
	return &testEnvironment{
		events: []interface{}{
			onAddOrUpdateEvent(isAdd, remoteService("test-service", "test-namespace", "currentResVersion", map[string]string{}, nil)),
		},
		localResources: []string{
			asYaml(mirrorService("test-service-remote", "test-namespace", "currentResVersion", nil, nil)),
			asYaml(endpoints("test-service-remote", "test-namespace", nil, "0.0.0.0", "", nil)),
		},
		link: v1alpha3.Link{
			Spec: v1alpha3.LinkSpec{
				TargetClusterName:       clusterName,
				TargetClusterDomain:     clusterDomain,
				GatewayIdentity:         "gateway-identity",
				GatewayAddress:          "192.0.2.127",
				GatewayPort:             "888",
				ProbeSpec:               defaultProbeSpec,
				Selector:                defaultSelector,
				RemoteDiscoverySelector: defaultRemoteDiscoverySelector,
			},
		},
	}
}

var onDeleteExportedService = &testEnvironment{
	events: []interface{}{
		&OnDeleteCalled{
			svc: remoteService("test-service", "test-namespace", "currentResVersion", map[string]string{
				consts.DefaultExportedServiceSelector: "true",
			}, nil),
		},
	},
	link: v1alpha3.Link{
		Spec: v1alpha3.LinkSpec{
			TargetClusterName:       clusterName,
			TargetClusterDomain:     clusterDomain,
			GatewayIdentity:         "gateway-identity",
			GatewayAddress:          "192.0.2.127",
			GatewayPort:             "888",
			ProbeSpec:               defaultProbeSpec,
			Selector:                defaultSelector,
			RemoteDiscoverySelector: defaultRemoteDiscoverySelector,
		},
	},
}

var onDeleteNonExportedService = &testEnvironment{
	events: []interface{}{
		&OnDeleteCalled{
			svc: remoteService("gateway", "test-namespace", "currentResVersion", map[string]string{}, nil),
		},
	},
	link: v1alpha3.Link{
		Spec: v1alpha3.LinkSpec{
			TargetClusterName:       clusterName,
			TargetClusterDomain:     clusterDomain,
			GatewayIdentity:         "gateway-identity",
			GatewayAddress:          "192.0.2.127",
			GatewayPort:             "888",
			ProbeSpec:               defaultProbeSpec,
			Selector:                defaultSelector,
			RemoteDiscoverySelector: defaultRemoteDiscoverySelector,
		},
	},
}

// the following tests ensure that onAdd, onUpdate and onDelete result in
// queueing more specific events to be processed

func onAddOrUpdateEvent(isAdd bool, svc *corev1.Service) interface{} {
	if isAdd {
		return &OnAddCalled{svc: svc}
	}
	return &OnUpdateCalled{svc: svc}
}

func diffServices(expected, actual *corev1.Service) error {
	if expected.Name != actual.Name {
		return fmt.Errorf("was expecting service with name %s but was %s", expected.Name, actual.Name)
	}

	if expected.Namespace != actual.Namespace {
		return fmt.Errorf("was expecting service with namespace %s but was %s", expected.Namespace, actual.Namespace)
	}

	if diff := deep.Equal(expected.Annotations, actual.Annotations); diff != nil {
		return fmt.Errorf("annotation mismatch %+v", diff)
	}

	if diff := deep.Equal(expected.Labels, actual.Labels); diff != nil {
		return fmt.Errorf("label mismatch %+v", diff)
	}

	return nil
}

func diffEndpoints(expected, actual *corev1.Endpoints) error {
	if expected.Name != actual.Name {
		return fmt.Errorf("was expecting endpoints with name %s but was %s", expected.Name, actual.Name)
	}

	if expected.Namespace != actual.Namespace {
		return fmt.Errorf("was expecting endpoints with namespace %s but was %s", expected.Namespace, actual.Namespace)
	}

	if diff := deep.Equal(expected.Annotations, actual.Annotations); diff != nil {
		return fmt.Errorf("annotation mismatch %+v", diff)
	}

	if diff := deep.Equal(expected.Labels, actual.Labels); diff != nil {
		return fmt.Errorf("label mismatch %+v", diff)
	}

	if diff := deep.Equal(expected.Subsets, actual.Subsets); diff != nil {
		return fmt.Errorf("subsets mismatch %+v", diff)
	}

	return nil
}

func remoteService(name, namespace, resourceVersion string, labels map[string]string, ports []corev1.ServicePort) *corev1.Service {
	return &corev1.Service{
		TypeMeta: metav1.TypeMeta{
			Kind:       "Service",
			APIVersion: "v1",
		},
		ObjectMeta: metav1.ObjectMeta{
			Name:            name,
			Namespace:       namespace,
			ResourceVersion: resourceVersion,
			Labels:          labels,
		},
		Spec: corev1.ServiceSpec{
			Ports: ports,
		},
	}
}

func remoteHeadlessService(name, namespace, resourceVersion string, labels map[string]string, ports []corev1.ServicePort) *corev1.Service {
	return &corev1.Service{
		TypeMeta: metav1.TypeMeta{
			Kind:       "Service",
			APIVersion: "v1",
		},
		ObjectMeta: metav1.ObjectMeta{
			Name:            name,
			Namespace:       namespace,
			ResourceVersion: resourceVersion,
			Labels:          labels,
		},
		Spec: corev1.ServiceSpec{
			ClusterIP: "None",
			Ports:     ports,
		},
	}
}

func remoteHeadlessEndpoints(name, namespace, resourceVersion, address string, ports []corev1.EndpointPort) *corev1.Endpoints {
	return &corev1.Endpoints{
		TypeMeta: metav1.TypeMeta{
			Kind:       "Endpoints",
			APIVersion: "v1",
		},
		ObjectMeta: metav1.ObjectMeta{
			Name:            name,
			Namespace:       namespace,
			ResourceVersion: resourceVersion,
			Labels: map[string]string{
				"service.kubernetes.io/headless":      "",
				consts.DefaultExportedServiceSelector: "true",
			},
		},
		Subsets: []corev1.EndpointSubset{
			{
				Addresses: []corev1.EndpointAddress{
					{
						Hostname: "pod-0",
						IP:       address,
						TargetRef: &corev1.ObjectReference{
							Name:            "pod-0",
							ResourceVersion: resourceVersion,
						},
					},
				},
				Ports: ports,
			},
		},
	}
}

func remoteHeadlessEndpointsUpdate(name, namespace, resourceVersion, address string, ports []corev1.EndpointPort) *corev1.Endpoints {
	return &corev1.Endpoints{
		TypeMeta: metav1.TypeMeta{
			Kind:       "Endpoints",
			APIVersion: "v1",
		},
		ObjectMeta: metav1.ObjectMeta{
			Name:            name,
			Namespace:       namespace,
			ResourceVersion: resourceVersion,
			Labels: map[string]string{
				"service.kubernetes.io/headless":      "",
				consts.DefaultExportedServiceSelector: "true",
			},
		},
		Subsets: []corev1.EndpointSubset{
			{
				Addresses: []corev1.EndpointAddress{
					{
						Hostname: "pod-0",
						IP:       address,
						TargetRef: &corev1.ObjectReference{
							Name:            "pod-0",
							ResourceVersion: resourceVersion,
						},
					},
					{
						Hostname: "pod-1",
						IP:       address,
						TargetRef: &corev1.ObjectReference{
							Name:            "pod-1",
							ResourceVersion: resourceVersion,
						},
					},
				},
				Ports: ports,
			},
		},
	}
}

func mirrorService(name, namespace, resourceVersion string, labels map[string]string, ports []corev1.ServicePort) *corev1.Service {
	annotations := make(map[string]string)
	annotations[consts.RemoteResourceVersionAnnotation] = resourceVersion
	annotations[consts.RemoteServiceFqName] = fmt.Sprintf("%s.%s.svc.cluster.local", strings.Replace(name, "-remote", "", 1), namespace)

	if labels == nil {
		labels = make(map[string]string)
	}
	labels[consts.RemoteClusterNameLabel] = clusterName
	labels[consts.MirroredResourceLabel] = "true"

	return &corev1.Service{
		TypeMeta: metav1.TypeMeta{
			Kind:       "Service",
			APIVersion: "v1",
		},
		ObjectMeta: metav1.ObjectMeta{
			Name:        name,
			Namespace:   namespace,
			Labels:      labels,
			Annotations: annotations,
		},
		Spec: corev1.ServiceSpec{
			Ports: ports,
		},
	}
}

func headlessMirrorService(name, namespace, resourceVersion string, labels map[string]string, ports []corev1.ServicePort) *corev1.Service {
	svc := mirrorService(name, namespace, resourceVersion, labels, ports)
	svc.Spec.ClusterIP = "None"
	return svc
}

func endpointMirrorService(hostname, rootName, namespace, resourceVersion string, labels map[string]string, ports []corev1.ServicePort) *corev1.Service {
	annotations := make(map[string]string)
	annotations[consts.RemoteResourceVersionAnnotation] = resourceVersion
	annotations[consts.RemoteServiceFqName] = fmt.Sprintf("%s.%s.%s.svc.cluster.local", hostname, strings.Replace(rootName, "-remote", "", 1), namespace)

	if labels == nil {
		labels = make(map[string]string)
	}
	labels[consts.MirroredHeadlessSvcNameLabel] = rootName
	labels[consts.RemoteClusterNameLabel] = clusterName
	labels[consts.MirroredResourceLabel] = "true"

	return &corev1.Service{
		TypeMeta: metav1.TypeMeta{
			Kind:       "Service",
			APIVersion: "v1",
		},
		ObjectMeta: metav1.ObjectMeta{
			Name:        fmt.Sprintf("%s-%s", hostname, clusterName),
			Namespace:   namespace,
			Labels:      labels,
			Annotations: annotations,
		},
		Spec: corev1.ServiceSpec{
			Ports: ports,
		},
	}
}

func remoteDiscoveryMirrorService(name, namespace, resourceVersion string, ports []corev1.ServicePort) *corev1.Service {
	annotations := make(map[string]string)
	annotations[consts.RemoteResourceVersionAnnotation] = resourceVersion
	annotations[consts.RemoteServiceFqName] = fmt.Sprintf("%s.%s.svc.cluster.local", name, namespace)

	return &corev1.Service{
		TypeMeta: metav1.TypeMeta{
			Kind:       "Service",
			APIVersion: "v1",
		},
		ObjectMeta: metav1.ObjectMeta{
			Name:      fmt.Sprintf("%s-%s", name, clusterName),
			Namespace: namespace,
			Labels: map[string]string{
				consts.RemoteClusterNameLabel: clusterName,
				consts.MirroredResourceLabel:  "true",
				consts.RemoteDiscoveryLabel:   clusterName,
				consts.RemoteServiceLabel:     name,
			},
			Annotations: annotations,
		},
		Spec: corev1.ServiceSpec{
			Ports: ports,
		},
	}
}

//nolint:unparam
func federatedService(name, namespace string, ports []corev1.ServicePort, localDiscovery, remoteDiscovery string) *corev1.Service {
	annotations := make(map[string]string)
	if localDiscovery != "" {
		annotations[consts.LocalDiscoveryAnnotation] = localDiscovery
	}
	if remoteDiscovery != "" {
		annotations[consts.RemoteDiscoveryAnnotation] = remoteDiscovery
	}

	return &corev1.Service{
		TypeMeta: metav1.TypeMeta{
			Kind:       "Service",
			APIVersion: "v1",
		},
		ObjectMeta: metav1.ObjectMeta{
			Name:      fmt.Sprintf("%s-federated", name),
			Namespace: namespace,
			Labels: map[string]string{
				consts.MirroredResourceLabel: "true",
			},
			Annotations: annotations,
		},
		Spec: corev1.ServiceSpec{
			Ports: ports,
		},
	}
}

func asYaml(obj interface{}) string {
	bytes, err := yaml.Marshal(obj)
	if err != nil {
		log.Fatal(err)
	}
	return string(bytes)
}

func gateway(name, namespace, resourceVersion, ip, portName string, port int32, identity string, probePort int32, probePath string, probePeriod string) *corev1.Service {
	svc := corev1.Service{
		TypeMeta: metav1.TypeMeta{
			Kind:       "Service",
			APIVersion: "v1",
		},
		ObjectMeta: metav1.ObjectMeta{
			Name:            name,
			Namespace:       namespace,
			ResourceVersion: resourceVersion,
			Annotations: map[string]string{
				consts.GatewayIdentity:    identity,
				consts.GatewayProbePath:   probePath,
				consts.GatewayProbePeriod: probePeriod,
			},
		},
		Spec: corev1.ServiceSpec{
			Ports: []corev1.ServicePort{
				{
					Name:     portName,
					Protocol: "TCP",
					Port:     port,
				},
				{
					Name:     consts.ProbePortName,
					Protocol: "TCP",
					Port:     probePort,
				},
			},
		},
	}

	if ip != "" {
		svc.Status.LoadBalancer.Ingress = append(svc.Status.LoadBalancer.Ingress, corev1.LoadBalancerIngress{IP: ip})
	}
	return &svc
}

func endpoints(name, namespace string, labels map[string]string, gatewayIP string, gatewayIdentity string, ports []corev1.EndpointPort) *corev1.Endpoints {
	var subsets []corev1.EndpointSubset
	if gatewayIP != "" {
		subsets = []corev1.EndpointSubset{
			{
				Addresses: []corev1.EndpointAddress{
					{
						IP: gatewayIP,
					},
				},
				Ports: ports,
			},
		}
	}

	if labels == nil {
		labels = make(map[string]string)
	}
	labels[consts.RemoteClusterNameLabel] = clusterName
	labels[consts.MirroredResourceLabel] = "true"

	endpoints := &corev1.Endpoints{
		TypeMeta: metav1.TypeMeta{
			Kind:       "Endpoints",
			APIVersion: "v1",
		},
		ObjectMeta: metav1.ObjectMeta{
			Name:      name,
			Namespace: namespace,
			Labels:    labels,
			Annotations: map[string]string{
				consts.RemoteServiceFqName: fmt.Sprintf("%s.%s.svc.cluster.local", strings.Replace(name, "-remote", "", 1), namespace),
			},
		},
		Subsets: subsets,
	}

	if gatewayIdentity != "" {
		endpoints.Annotations[consts.RemoteGatewayIdentity] = gatewayIdentity
	}

	return endpoints
}

func endpointMirrorEndpoints(rootName, namespace string, labels map[string]string, hostname, gatewayIP, gatewayIdentity string, ports []corev1.EndpointPort) *corev1.Endpoints {
	localName := fmt.Sprintf("%s-%s", hostname, clusterName)
	ep := endpoints(localName, namespace, labels, gatewayIP, gatewayIdentity, ports)

	ep.Annotations[consts.RemoteServiceFqName] = fmt.Sprintf("%s.%s.%s.svc.cluster.local", hostname, strings.Replace(rootName, "-remote", "", 1), namespace)
	ep.Labels[consts.MirroredHeadlessSvcNameLabel] = rootName

	return ep
}

func headlessMirrorEndpoints(name, namespace string, labels map[string]string, gatewayIdentity string, ports []corev1.EndpointPort) *corev1.Endpoints {
	if labels == nil {
		labels = make(map[string]string)
	}
	labels[consts.RemoteClusterNameLabel] = clusterName
	labels[consts.MirroredResourceLabel] = "true"
	endpoints := &corev1.Endpoints{
		TypeMeta: metav1.TypeMeta{
			Kind:       "Endpoints",
			APIVersion: "v1",
		},
		ObjectMeta: metav1.ObjectMeta{
			Name:      name,
			Namespace: namespace,
			Labels:    labels,
			Annotations: map[string]string{
				consts.RemoteServiceFqName: fmt.Sprintf("%s.%s.svc.cluster.local", strings.Replace(name, "-remote", "", 1), namespace),
			},
		},
		Subsets: []corev1.EndpointSubset{
			{
				Addresses: []corev1.EndpointAddress{
					{
						Hostname: "pod-0",
						IP:       "",
					},
				},
				Ports: ports,
			},
		},
	}

	if gatewayIdentity != "" {
		endpoints.Annotations[consts.RemoteGatewayIdentity] = gatewayIdentity
	}

	return endpoints
}

func headlessMirrorEndpointsUpdated(name, namespace string, hostnames, hostIPs []string, gatewayIdentity string, ports []corev1.EndpointPort) *corev1.Endpoints {
	endpoints := &corev1.Endpoints{
		TypeMeta: metav1.TypeMeta{
			Kind:       "Endpoints",
			APIVersion: "v1",
		},
		ObjectMeta: metav1.ObjectMeta{
			Name:      name,
			Namespace: namespace,
			Labels: map[string]string{
				consts.RemoteClusterNameLabel: clusterName,
				consts.MirroredResourceLabel:  "true",
			},
			Annotations: map[string]string{
				consts.RemoteServiceFqName: fmt.Sprintf("%s.%s.svc.cluster.local", strings.Replace(name, "-remote", "", 1), namespace),
			},
		},
		Subsets: []corev1.EndpointSubset{
			{
				Addresses: []corev1.EndpointAddress{
					{
						Hostname: hostnames[0],
						IP:       hostIPs[0],
					},
					{
						Hostname: hostnames[1],
						IP:       hostIPs[1],
					},
				},
				Ports: ports,
			},
		},
	}

	if gatewayIdentity != "" {
		endpoints.Annotations[consts.RemoteGatewayIdentity] = gatewayIdentity
	}

	return endpoints
}

func namespace(name string) *corev1.Namespace {
	return &corev1.Namespace{
		TypeMeta: metav1.TypeMeta{
			Kind:       "Namespace",
			APIVersion: "v1",
		},
		ObjectMeta: metav1.ObjectMeta{
			Name: name,
		},
	}
}

// createEnvWithSelector will create a test environment with two services. It
// accepts a default and a remote discovery selector which it will use for the
// link creation. This function is used to create environments that differ only
// in the selector used in the link.
func createEnvWithSelector(defaultSelector, remoteSelector *metav1.LabelSelector) *testEnvironment {
	return &testEnvironment{
		events: []interface{}{
			&OnAddCalled{
				svc: remoteService("service-one", "ns1", "111", map[string]string{
					consts.DefaultExportedServiceSelector: "true",
				}, []corev1.ServicePort{
					{
						Name:     "default1",
						Protocol: "TCP",
						Port:     555,
					},
					{
						Name:     "default2",
						Protocol: "TCP",
						Port:     666,
					},
				}),
			},
			&OnAddCalled{
				svc: remoteService("service-two", "ns1", "111", map[string]string{
					consts.DefaultExportedServiceSelector: "remote-discovery",
				}, []corev1.ServicePort{
					{
						Name:     "remote1",
						Protocol: "TCP",
						Port:     777,
					},
					{
						Name:     "remote2",
						Protocol: "TCP",
						Port:     888,
					},
				}),
			},
		},
		localResources: []string{
			asYaml(namespace("ns1")),
		},
		remoteResources: []string{
			asYaml(endpoints("service-one", "ns1", nil, "192.0.2.127", "gateway-identity", []corev1.EndpointPort{})),
			asYaml(endpoints("service-two", "ns1", nil, "192.0.3.127", "gateway-identity", []corev1.EndpointPort{})),
		},
		link: v1alpha3.Link{
			Spec: v1alpha3.LinkSpec{
				TargetClusterName:       clusterName,
				TargetClusterDomain:     clusterDomain,
				Selector:                defaultSelector,
				RemoteDiscoverySelector: remoteSelector,
			},
		},
	}
}