/*
Copyright 2021 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 source

import (
	"context"
	"testing"

	"github.com/stretchr/testify/require"
	corev1 "k8s.io/api/core/v1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/client-go/kubernetes/fake"
	"sigs.k8s.io/external-dns/endpoint"
)

// testPodSource tests that various services generate the correct endpoints.
func TestPodSource(t *testing.T) {
	t.Parallel()

	for _, tc := range []struct {
		title           string
		targetNamespace string
		compatibility   string
		expected        []*endpoint.Endpoint
		expectError     bool
		nodes           []*corev1.Node
		pods            []*corev1.Pod
	}{
		{
			"create records based on pod's external and internal IPs",
			"",
			"",
			[]*endpoint.Endpoint{
				{DNSName: "a.foo.example.org", Targets: endpoint.Targets{"54.10.11.1", "54.10.11.2"}, RecordType: endpoint.RecordTypeA},
				{DNSName: "internal.a.foo.example.org", Targets: endpoint.Targets{"10.0.1.1", "10.0.1.2"}, RecordType: endpoint.RecordTypeA},
			},
			false,
			[]*corev1.Node{
				{
					ObjectMeta: metav1.ObjectMeta{
						Name: "my-node1",
					},
					Status: corev1.NodeStatus{
						Addresses: []corev1.NodeAddress{
							{Type: corev1.NodeExternalIP, Address: "54.10.11.1"},
							{Type: corev1.NodeInternalIP, Address: "10.0.1.1"},
						},
					},
				},
				{
					ObjectMeta: metav1.ObjectMeta{
						Name: "my-node2",
					},
					Status: corev1.NodeStatus{
						Addresses: []corev1.NodeAddress{
							{Type: corev1.NodeExternalIP, Address: "54.10.11.2"},
							{Type: corev1.NodeInternalIP, Address: "10.0.1.2"},
						},
					},
				},
			},
			[]*corev1.Pod{
				{
					ObjectMeta: metav1.ObjectMeta{
						Name:      "my-pod1",
						Namespace: "kube-system",
						Annotations: map[string]string{
							internalHostnameAnnotationKey: "internal.a.foo.example.org",
							hostnameAnnotationKey:         "a.foo.example.org",
						},
					},
					Spec: corev1.PodSpec{
						HostNetwork: true,
						NodeName:    "my-node1",
					},
					Status: corev1.PodStatus{
						PodIP: "10.0.1.1",
					},
				},
				{
					ObjectMeta: metav1.ObjectMeta{
						Name:      "my-pod2",
						Namespace: "kube-system",
						Annotations: map[string]string{
							internalHostnameAnnotationKey: "internal.a.foo.example.org",
							hostnameAnnotationKey:         "a.foo.example.org",
						},
					},
					Spec: corev1.PodSpec{
						HostNetwork: true,
						NodeName:    "my-node2",
					},
					Status: corev1.PodStatus{
						PodIP: "10.0.1.2",
					},
				},
			},
		},
		{
			"create records based on pod's external and internal IPs using DNS Controller annotations",
			"",
			"kops-dns-controller",
			[]*endpoint.Endpoint{
				{DNSName: "a.foo.example.org", Targets: endpoint.Targets{"54.10.11.1", "54.10.11.2"}, RecordType: endpoint.RecordTypeA},
				{DNSName: "internal.a.foo.example.org", Targets: endpoint.Targets{"10.0.1.1", "10.0.1.2"}, RecordType: endpoint.RecordTypeA},
			},
			false,
			[]*corev1.Node{
				{
					ObjectMeta: metav1.ObjectMeta{
						Name: "my-node1",
					},
					Status: corev1.NodeStatus{
						Addresses: []corev1.NodeAddress{
							{Type: corev1.NodeExternalIP, Address: "54.10.11.1"},
							{Type: corev1.NodeInternalIP, Address: "10.0.1.1"},
						},
					},
				},
				{
					ObjectMeta: metav1.ObjectMeta{
						Name: "my-node2",
					},
					Status: corev1.NodeStatus{
						Addresses: []corev1.NodeAddress{
							{Type: corev1.NodeExternalIP, Address: "54.10.11.2"},
							{Type: corev1.NodeInternalIP, Address: "10.0.1.2"},
						},
					},
				},
			},
			[]*corev1.Pod{
				{
					ObjectMeta: metav1.ObjectMeta{
						Name:      "my-pod1",
						Namespace: "kube-system",
						Annotations: map[string]string{
							kopsDNSControllerInternalHostnameAnnotationKey: "internal.a.foo.example.org",
							kopsDNSControllerHostnameAnnotationKey:         "a.foo.example.org",
						},
					},
					Spec: corev1.PodSpec{
						HostNetwork: true,
						NodeName:    "my-node1",
					},
					Status: corev1.PodStatus{
						PodIP: "10.0.1.1",
					},
				},
				{
					ObjectMeta: metav1.ObjectMeta{
						Name:      "my-pod2",
						Namespace: "kube-system",
						Annotations: map[string]string{
							kopsDNSControllerInternalHostnameAnnotationKey: "internal.a.foo.example.org",
							kopsDNSControllerHostnameAnnotationKey:         "a.foo.example.org",
						},
					},
					Spec: corev1.PodSpec{
						HostNetwork: true,
						NodeName:    "my-node2",
					},
					Status: corev1.PodStatus{
						PodIP: "10.0.1.2",
					},
				},
			},
		},
		{
			"create multiple records",
			"",
			"",
			[]*endpoint.Endpoint{
				{DNSName: "a.foo.example.org", Targets: endpoint.Targets{"54.10.11.1"}, RecordType: endpoint.RecordTypeA},
				{DNSName: "b.foo.example.org", Targets: endpoint.Targets{"54.10.11.2"}, RecordType: endpoint.RecordTypeA},
			},
			false,
			[]*corev1.Node{
				{
					ObjectMeta: metav1.ObjectMeta{
						Name: "my-node1",
					},
					Status: corev1.NodeStatus{
						Addresses: []corev1.NodeAddress{
							{Type: corev1.NodeExternalIP, Address: "54.10.11.1"},
							{Type: corev1.NodeInternalIP, Address: "10.0.1.1"},
						},
					},
				},
				{
					ObjectMeta: metav1.ObjectMeta{
						Name: "my-node2",
					},
					Status: corev1.NodeStatus{
						Addresses: []corev1.NodeAddress{
							{Type: corev1.NodeExternalIP, Address: "54.10.11.2"},
							{Type: corev1.NodeInternalIP, Address: "10.0.1.2"},
						},
					},
				},
			},
			[]*corev1.Pod{
				{
					ObjectMeta: metav1.ObjectMeta{
						Name:      "my-pod1",
						Namespace: "kube-system",
						Annotations: map[string]string{
							hostnameAnnotationKey: "a.foo.example.org",
						},
					},
					Spec: corev1.PodSpec{
						HostNetwork: true,
						NodeName:    "my-node1",
					},
					Status: corev1.PodStatus{
						PodIP: "10.0.1.1",
					},
				},
				{
					ObjectMeta: metav1.ObjectMeta{
						Name:      "my-pod2",
						Namespace: "kube-system",
						Annotations: map[string]string{
							hostnameAnnotationKey: "b.foo.example.org",
						},
					},
					Spec: corev1.PodSpec{
						HostNetwork: true,
						NodeName:    "my-node2",
					},
					Status: corev1.PodStatus{
						PodIP: "10.0.1.2",
					},
				},
			},
		},
		{
			"pods with hostNetwore=false should be ignored",
			"",
			"",
			[]*endpoint.Endpoint{
				{DNSName: "a.foo.example.org", Targets: endpoint.Targets{"54.10.11.1"}, RecordType: endpoint.RecordTypeA},
				{DNSName: "internal.a.foo.example.org", Targets: endpoint.Targets{"10.0.1.1"}, RecordType: endpoint.RecordTypeA},
			},
			false,
			[]*corev1.Node{
				{
					ObjectMeta: metav1.ObjectMeta{
						Name: "my-node1",
					},
					Status: corev1.NodeStatus{
						Addresses: []corev1.NodeAddress{
							{Type: corev1.NodeExternalIP, Address: "54.10.11.1"},
							{Type: corev1.NodeInternalIP, Address: "10.0.1.1"},
						},
					},
				},
				{
					ObjectMeta: metav1.ObjectMeta{
						Name: "my-node2",
					},
					Status: corev1.NodeStatus{
						Addresses: []corev1.NodeAddress{
							{Type: corev1.NodeExternalIP, Address: "54.10.11.2"},
							{Type: corev1.NodeInternalIP, Address: "10.0.1.2"},
						},
					},
				},
			},
			[]*corev1.Pod{
				{
					ObjectMeta: metav1.ObjectMeta{
						Name:      "my-pod1",
						Namespace: "kube-system",
						Annotations: map[string]string{
							internalHostnameAnnotationKey: "internal.a.foo.example.org",
							hostnameAnnotationKey:         "a.foo.example.org",
						},
					},
					Spec: corev1.PodSpec{
						HostNetwork: true,
						NodeName:    "my-node1",
					},
					Status: corev1.PodStatus{
						PodIP: "10.0.1.1",
					},
				},
				{
					ObjectMeta: metav1.ObjectMeta{
						Name:      "my-pod2",
						Namespace: "kube-system",
						Annotations: map[string]string{
							internalHostnameAnnotationKey: "internal.a.foo.example.org",
							hostnameAnnotationKey:         "a.foo.example.org",
						},
					},
					Spec: corev1.PodSpec{
						HostNetwork: false,
						NodeName:    "my-node2",
					},
					Status: corev1.PodStatus{
						PodIP: "100.0.1.2",
					},
				},
			},
		},
		{
			"only watch a given namespace",
			"kube-system",
			"",
			[]*endpoint.Endpoint{
				{DNSName: "a.foo.example.org", Targets: endpoint.Targets{"54.10.11.1"}, RecordType: endpoint.RecordTypeA},
				{DNSName: "internal.a.foo.example.org", Targets: endpoint.Targets{"10.0.1.1"}, RecordType: endpoint.RecordTypeA},
			},
			false,
			[]*corev1.Node{
				{
					ObjectMeta: metav1.ObjectMeta{
						Name: "my-node1",
					},
					Status: corev1.NodeStatus{
						Addresses: []corev1.NodeAddress{
							{Type: corev1.NodeExternalIP, Address: "54.10.11.1"},
							{Type: corev1.NodeInternalIP, Address: "10.0.1.1"},
						},
					},
				},
				{
					ObjectMeta: metav1.ObjectMeta{
						Name: "my-node2",
					},
					Status: corev1.NodeStatus{
						Addresses: []corev1.NodeAddress{
							{Type: corev1.NodeExternalIP, Address: "54.10.11.2"},
							{Type: corev1.NodeInternalIP, Address: "10.0.1.2"},
						},
					},
				},
			},
			[]*corev1.Pod{
				{
					ObjectMeta: metav1.ObjectMeta{
						Name:      "my-pod1",
						Namespace: "kube-system",
						Annotations: map[string]string{
							internalHostnameAnnotationKey: "internal.a.foo.example.org",
							hostnameAnnotationKey:         "a.foo.example.org",
						},
					},
					Spec: corev1.PodSpec{
						HostNetwork: true,
						NodeName:    "my-node1",
					},
					Status: corev1.PodStatus{
						PodIP: "10.0.1.1",
					},
				},
				{
					ObjectMeta: metav1.ObjectMeta{
						Name:      "my-pod2",
						Namespace: "default",
						Annotations: map[string]string{
							internalHostnameAnnotationKey: "internal.a.foo.example.org",
							hostnameAnnotationKey:         "a.foo.example.org",
						},
					},
					Spec: corev1.PodSpec{
						HostNetwork: true,
						NodeName:    "my-node2",
					},
					Status: corev1.PodStatus{
						PodIP: "100.0.1.2",
					},
				},
			},
		},
	} {
		tc := tc
		t.Run(tc.title, func(t *testing.T) {
			t.Parallel()

			// Create a Kubernetes testing client
			kubernetes := fake.NewSimpleClientset()
			ctx := context.Background()

			// Create the nodes
			for _, node := range tc.nodes {
				if _, err := kubernetes.CoreV1().Nodes().Create(ctx, node, metav1.CreateOptions{}); err != nil {
					t.Fatal(err)
				}
			}

			for _, pod := range tc.pods {
				pods := kubernetes.CoreV1().Pods(pod.Namespace)

				if _, err := pods.Create(ctx, pod, metav1.CreateOptions{}); err != nil {
					t.Fatal(err)
				}
			}

			client, err := NewPodSource(kubernetes, tc.targetNamespace, tc.compatibility)
			require.NoError(t, err)

			endpoints, err := client.Endpoints(ctx)
			if tc.expectError {
				require.Error(t, err)
			} else {
				require.NoError(t, err)
			}

			// Validate returned endpoints against desired endpoints.
			validateEndpoints(t, endpoints, tc.expected)
		})

	}
}