/*
Copyright 2019 The Kubernetes Authors.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package reconcilers

import (
	"fmt"
	"testing"

	corev1 "k8s.io/api/core/v1"
	discovery "k8s.io/api/discovery/v1alpha1"
	apiequality "k8s.io/apimachinery/pkg/api/equality"
	"k8s.io/apimachinery/pkg/api/errors"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/runtime/schema"
	"k8s.io/client-go/kubernetes/fake"
)

func TestEndpointsAdapterGet(t *testing.T) {
	endpoints1, _ := generateEndpointsAndSlice("foo", "testing", []int{80, 443}, []string{"10.1.2.3", "10.1.2.4"})

	testCases := map[string]struct {
		endpointSlicesEnabled bool
		expectedError         error
		expectedEndpoints     *corev1.Endpoints
		endpoints             []*corev1.Endpoints
		namespaceParam        string
		nameParam             string
	}{
		"single-existing-endpoints": {
			endpointSlicesEnabled: false,
			expectedError:         nil,
			expectedEndpoints:     endpoints1,
			endpoints:             []*corev1.Endpoints{endpoints1},
			namespaceParam:        "testing",
			nameParam:             "foo",
		},
		"single-existing-endpoints-slices-enabled": {
			endpointSlicesEnabled: true,
			expectedError:         nil,
			expectedEndpoints:     endpoints1,
			endpoints:             []*corev1.Endpoints{endpoints1},
			namespaceParam:        "testing",
			nameParam:             "foo",
		},
		"wrong-namespace": {
			endpointSlicesEnabled: false,
			expectedError:         errors.NewNotFound(schema.GroupResource{Group: "", Resource: "endpoints"}, "foo"),
			expectedEndpoints:     nil,
			endpoints:             []*corev1.Endpoints{endpoints1},
			namespaceParam:        "foo",
			nameParam:             "foo",
		},
		"wrong-name": {
			endpointSlicesEnabled: false,
			expectedError:         errors.NewNotFound(schema.GroupResource{Group: "", Resource: "endpoints"}, "bar"),
			expectedEndpoints:     nil,
			endpoints:             []*corev1.Endpoints{endpoints1},
			namespaceParam:        "testing",
			nameParam:             "bar",
		},
	}

	for name, testCase := range testCases {
		t.Run(name, func(t *testing.T) {
			client := fake.NewSimpleClientset()
			epAdapter := EndpointsAdapter{endpointClient: client.CoreV1()}
			if testCase.endpointSlicesEnabled {
				epAdapter.endpointSliceClient = client.DiscoveryV1alpha1()
			}

			for _, endpoints := range testCase.endpoints {
				_, err := client.CoreV1().Endpoints(endpoints.Namespace).Create(endpoints)
				if err != nil {
					t.Fatalf("Error creating Endpoints: %v", err)
				}
			}

			endpoints, err := epAdapter.Get(testCase.namespaceParam, testCase.nameParam, metav1.GetOptions{})

			if !apiequality.Semantic.DeepEqual(testCase.expectedError, err) {
				t.Errorf("Expected error: %v, got: %v", testCase.expectedError, err)
			}

			if !apiequality.Semantic.DeepEqual(endpoints, testCase.expectedEndpoints) {
				t.Errorf("Expected endpoints: %v, got: %v", testCase.expectedEndpoints, endpoints)
			}
		})
	}
}

func TestEndpointsAdapterCreate(t *testing.T) {
	endpoints1, epSlice1 := generateEndpointsAndSlice("foo", "testing", []int{80}, []string{"10.1.2.3", "10.1.2.4"})

	testCases := map[string]struct {
		endpointSlicesEnabled bool
		expectedError         error
		expectedEndpoints     *corev1.Endpoints
		expectedEndpointSlice *discovery.EndpointSlice
		endpoints             []*corev1.Endpoints
		endpointSlices        []*discovery.EndpointSlice
		namespaceParam        string
		endpointsParam        *corev1.Endpoints
	}{
		"single-endpoint": {
			endpointSlicesEnabled: true,
			expectedError:         nil,
			expectedEndpoints:     endpoints1,
			expectedEndpointSlice: epSlice1,
			endpoints:             []*corev1.Endpoints{},
			namespaceParam:        endpoints1.Namespace,
			endpointsParam:        endpoints1,
		},
		"single-endpoint-no-slices": {
			endpointSlicesEnabled: false,
			expectedError:         nil,
			expectedEndpoints:     endpoints1,
			expectedEndpointSlice: nil,
			endpoints:             []*corev1.Endpoints{},
			namespaceParam:        endpoints1.Namespace,
			endpointsParam:        endpoints1,
		},
		"existing-endpoint": {
			endpointSlicesEnabled: true,
			expectedError:         errors.NewAlreadyExists(schema.GroupResource{Group: "", Resource: "endpoints"}, "foo"),
			expectedEndpoints:     nil,
			expectedEndpointSlice: nil,
			endpoints:             []*corev1.Endpoints{endpoints1},
			namespaceParam:        endpoints1.Namespace,
			endpointsParam:        endpoints1,
		},
	}

	for name, testCase := range testCases {
		t.Run(name, func(t *testing.T) {
			client := fake.NewSimpleClientset()
			epAdapter := EndpointsAdapter{endpointClient: client.CoreV1()}
			if testCase.endpointSlicesEnabled {
				epAdapter.endpointSliceClient = client.DiscoveryV1alpha1()
			}

			for _, endpoints := range testCase.endpoints {
				_, err := client.CoreV1().Endpoints(endpoints.Namespace).Create(endpoints)
				if err != nil {
					t.Fatalf("Error creating Endpoints: %v", err)
				}
			}

			endpoints, err := epAdapter.Create(testCase.namespaceParam, testCase.endpointsParam)

			if !apiequality.Semantic.DeepEqual(testCase.expectedError, err) {
				t.Errorf("Expected error: %v, got: %v", testCase.expectedError, err)
			}

			if !apiequality.Semantic.DeepEqual(endpoints, testCase.expectedEndpoints) {
				t.Errorf("Expected endpoints: %v, got: %v", testCase.expectedEndpoints, endpoints)
			}

			epSliceList, err := client.DiscoveryV1alpha1().EndpointSlices(testCase.namespaceParam).List(metav1.ListOptions{})
			if err != nil {
				t.Fatalf("Error listing Endpoint Slices: %v", err)
			}

			if testCase.expectedEndpointSlice == nil {
				if len(epSliceList.Items) != 0 {
					t.Fatalf("Expected no Endpoint Slices, got: %v", epSliceList.Items)
				}
			} else {
				if len(epSliceList.Items) == 0 {
					t.Fatalf("No Endpoint Slices found, expected: %v", testCase.expectedEndpointSlice)
				}
				if len(epSliceList.Items) > 1 {
					t.Errorf("Only 1 Endpoint Slice expected, got: %v", testCase.expectedEndpointSlice)
				}
				if !apiequality.Semantic.DeepEqual(*testCase.expectedEndpointSlice, epSliceList.Items[0]) {
					t.Errorf("Expected Endpoint Slice: %v, got: %v", testCase.expectedEndpointSlice, epSliceList.Items[0])

				}
			}
		})
	}
}

func TestEndpointsAdapterUpdate(t *testing.T) {
	endpoints1, _ := generateEndpointsAndSlice("foo", "testing", []int{80}, []string{"10.1.2.3", "10.1.2.4"})
	endpoints2, epSlice2 := generateEndpointsAndSlice("foo", "testing", []int{80, 443}, []string{"10.1.2.3", "10.1.2.4", "10.1.2.5"})
	endpoints3, _ := generateEndpointsAndSlice("bar", "testing", []int{80, 443}, []string{"10.1.2.3", "10.1.2.4", "10.1.2.5"})

	testCases := map[string]struct {
		endpointSlicesEnabled bool
		expectedError         error
		expectedEndpoints     *corev1.Endpoints
		expectedEndpointSlice *discovery.EndpointSlice
		endpoints             []*corev1.Endpoints
		endpointSlices        []*discovery.EndpointSlice
		namespaceParam        string
		endpointsParam        *corev1.Endpoints
	}{
		"single-existing-endpoints-no-change": {
			endpointSlicesEnabled: false,
			expectedError:         nil,
			expectedEndpoints:     endpoints1,
			expectedEndpointSlice: nil,
			endpoints:             []*corev1.Endpoints{endpoints1},
			namespaceParam:        "testing",
			endpointsParam:        endpoints1,
		},
		"add-ports-and-ips": {
			endpointSlicesEnabled: true,
			expectedError:         nil,
			expectedEndpoints:     endpoints2,
			expectedEndpointSlice: epSlice2,
			endpoints:             []*corev1.Endpoints{endpoints1},
			namespaceParam:        "testing",
			endpointsParam:        endpoints2,
		},
		"missing-endpoints": {
			endpointSlicesEnabled: true,
			expectedError:         errors.NewNotFound(schema.GroupResource{Group: "", Resource: "endpoints"}, "bar"),
			expectedEndpoints:     nil,
			expectedEndpointSlice: nil,
			endpoints:             []*corev1.Endpoints{endpoints1},
			namespaceParam:        "testing",
			endpointsParam:        endpoints3,
		},
	}

	for name, testCase := range testCases {
		t.Run(name, func(t *testing.T) {
			client := fake.NewSimpleClientset()
			epAdapter := EndpointsAdapter{endpointClient: client.CoreV1()}
			if testCase.endpointSlicesEnabled {
				epAdapter.endpointSliceClient = client.DiscoveryV1alpha1()
			}

			for _, endpoints := range testCase.endpoints {
				_, err := client.CoreV1().Endpoints(endpoints.Namespace).Create(endpoints)
				if err != nil {
					t.Fatalf("Error creating Endpoints: %v", err)
				}
			}

			endpoints, err := epAdapter.Update(testCase.namespaceParam, testCase.endpointsParam)

			if !apiequality.Semantic.DeepEqual(testCase.expectedError, err) {
				t.Errorf("Expected error: %v, got: %v", testCase.expectedError, err)
			}

			if !apiequality.Semantic.DeepEqual(endpoints, testCase.expectedEndpoints) {
				t.Errorf("Expected endpoints: %v, got: %v", testCase.expectedEndpoints, endpoints)
			}

			epSliceList, err := client.DiscoveryV1alpha1().EndpointSlices(testCase.namespaceParam).List(metav1.ListOptions{})
			if err != nil {
				t.Fatalf("Error listing Endpoint Slices: %v", err)
			}

			if testCase.expectedEndpointSlice == nil {
				if len(epSliceList.Items) != 0 {
					t.Fatalf("Expected no Endpoint Slices, got: %v", epSliceList.Items)
				}
			} else {
				if len(epSliceList.Items) == 0 {
					t.Fatalf("No Endpoint Slices found, expected: %v", testCase.expectedEndpointSlice)
				}
				if len(epSliceList.Items) > 1 {
					t.Errorf("Only 1 Endpoint Slice expected, got: %v", testCase.expectedEndpointSlice)
				}
				if !apiequality.Semantic.DeepEqual(*testCase.expectedEndpointSlice, epSliceList.Items[0]) {
					t.Errorf("Expected Endpoint Slice: %v, got: %v", testCase.expectedEndpointSlice, epSliceList.Items[0])

				}
			}
		})
	}
}

func generateEndpointsAndSlice(name, namespace string, ports []int, addresses []string) (*corev1.Endpoints, *discovery.EndpointSlice) {
	objectMeta := metav1.ObjectMeta{Name: name, Namespace: namespace}
	trueBool := true
	addressTypeIP := discovery.AddressTypeIP

	epSlice := &discovery.EndpointSlice{ObjectMeta: objectMeta, AddressType: &addressTypeIP}
	epSlice.Labels = map[string]string{discovery.LabelServiceName: name}
	subset := corev1.EndpointSubset{}

	for i, port := range ports {
		endpointPort := corev1.EndpointPort{
			Name:     fmt.Sprintf("port-%d", i),
			Port:     int32(port),
			Protocol: corev1.ProtocolTCP,
		}
		subset.Ports = append(subset.Ports, endpointPort)
		epSlice.Ports = append(epSlice.Ports, discovery.EndpointPort{
			Name:     &endpointPort.Name,
			Port:     &endpointPort.Port,
			Protocol: &endpointPort.Protocol,
		})
	}

	for i, address := range addresses {
		endpointAddress := corev1.EndpointAddress{
			IP: address,
			TargetRef: &corev1.ObjectReference{
				Kind: "Pod",
				Name: fmt.Sprintf("pod-%d", i),
			},
		}

		subset.Addresses = append(subset.Addresses, endpointAddress)

		epSlice.Endpoints = append(epSlice.Endpoints, discovery.Endpoint{
			Addresses:  []string{endpointAddress.IP},
			TargetRef:  endpointAddress.TargetRef,
			Conditions: discovery.EndpointConditions{Ready: &trueBool},
		})
	}

	return &corev1.Endpoints{
		ObjectMeta: objectMeta,
		Subsets:    []corev1.EndpointSubset{subset},
	}, epSlice
}