/*
Copyright 2020 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 debug

import (
	"fmt"
	"testing"
	"time"

	"github.com/google/go-cmp/cmp"
	corev1 "k8s.io/api/core/v1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/cli-runtime/pkg/genericclioptions"
	"k8s.io/utils/pointer"
)

func TestGenerateDebugContainer(t *testing.T) {
	// Slightly less randomness for testing.
	defer func(old func(int) string) { nameSuffixFunc = old }(nameSuffixFunc)
	var suffixCounter int
	nameSuffixFunc = func(int) string {
		suffixCounter++
		return fmt.Sprint(suffixCounter)
	}

	for _, tc := range []struct {
		name     string
		opts     *DebugOptions
		pod      *corev1.Pod
		expected *corev1.EphemeralContainer
	}{
		{
			name: "minimum fields",
			opts: &DebugOptions{
				Container:  "debugger",
				Image:      "busybox",
				PullPolicy: corev1.PullIfNotPresent,
			},
			expected: &corev1.EphemeralContainer{
				EphemeralContainerCommon: corev1.EphemeralContainerCommon{
					Name:                     "debugger",
					Image:                    "busybox",
					ImagePullPolicy:          "IfNotPresent",
					TerminationMessagePolicy: "File",
				},
			},
		},
		{
			name: "namespace targeting",
			opts: &DebugOptions{
				Container:  "debugger",
				Image:      "busybox",
				PullPolicy: corev1.PullIfNotPresent,
				Target:     "myapp",
			},
			expected: &corev1.EphemeralContainer{
				EphemeralContainerCommon: corev1.EphemeralContainerCommon{
					Name:                     "debugger",
					Image:                    "busybox",
					ImagePullPolicy:          "IfNotPresent",
					TerminationMessagePolicy: "File",
				},
				TargetContainerName: "myapp",
			},
		},
		{
			name: "debug args as container command",
			opts: &DebugOptions{
				Args:       []string{"/bin/echo", "one", "two", "three"},
				Container:  "debugger",
				Image:      "busybox",
				PullPolicy: corev1.PullIfNotPresent,
			},
			expected: &corev1.EphemeralContainer{
				EphemeralContainerCommon: corev1.EphemeralContainerCommon{
					Name:                     "debugger",
					Command:                  []string{"/bin/echo", "one", "two", "three"},
					Image:                    "busybox",
					ImagePullPolicy:          "IfNotPresent",
					TerminationMessagePolicy: "File",
				},
			},
		},
		{
			name: "debug args as container args",
			opts: &DebugOptions{
				ArgsOnly:   true,
				Container:  "debugger",
				Args:       []string{"echo", "one", "two", "three"},
				Image:      "busybox",
				PullPolicy: corev1.PullIfNotPresent,
			},
			expected: &corev1.EphemeralContainer{
				EphemeralContainerCommon: corev1.EphemeralContainerCommon{
					Name:                     "debugger",
					Args:                     []string{"echo", "one", "two", "three"},
					Image:                    "busybox",
					ImagePullPolicy:          "IfNotPresent",
					TerminationMessagePolicy: "File",
				},
			},
		},
		{
			name: "random name generation",
			opts: &DebugOptions{
				Image:      "busybox",
				PullPolicy: corev1.PullIfNotPresent,
			},
			expected: &corev1.EphemeralContainer{
				EphemeralContainerCommon: corev1.EphemeralContainerCommon{
					Name:                     "debugger-1",
					Image:                    "busybox",
					ImagePullPolicy:          "IfNotPresent",
					TerminationMessagePolicy: "File",
				},
			},
		},
		{
			name: "random name collision",
			opts: &DebugOptions{
				Image:      "busybox",
				PullPolicy: corev1.PullIfNotPresent,
			},
			pod: &corev1.Pod{
				Spec: corev1.PodSpec{
					Containers: []corev1.Container{
						{
							Name: "debugger-1",
						},
					},
				},
			},
			expected: &corev1.EphemeralContainer{
				EphemeralContainerCommon: corev1.EphemeralContainerCommon{
					Name:                     "debugger-2",
					Image:                    "busybox",
					ImagePullPolicy:          "IfNotPresent",
					TerminationMessagePolicy: "File",
				},
			},
		},
	} {
		t.Run(tc.name, func(t *testing.T) {
			tc.opts.IOStreams = genericclioptions.NewTestIOStreamsDiscard()
			suffixCounter = 0

			if tc.pod == nil {
				tc.pod = &corev1.Pod{}
			}
			if diff := cmp.Diff(tc.expected, tc.opts.generateDebugContainer(tc.pod)); diff != "" {
				t.Error("unexpected diff in generated object: (-want +got):\n", diff)
			}
		})
	}
}

func TestGeneratePodCopyWithDebugContainer(t *testing.T) {
	defer func(old func(int) string) { nameSuffixFunc = old }(nameSuffixFunc)
	var suffixCounter int
	nameSuffixFunc = func(int) string {
		suffixCounter++
		return fmt.Sprint(suffixCounter)
	}

	for _, tc := range []struct {
		name     string
		opts     *DebugOptions
		pod      *corev1.Pod
		expected *corev1.Pod
	}{
		{
			name: "basic",
			opts: &DebugOptions{
				CopyTo:     "debugger",
				Container:  "debugger",
				Image:      "busybox",
				PullPolicy: corev1.PullIfNotPresent,
			},
			pod: &corev1.Pod{
				ObjectMeta: metav1.ObjectMeta{
					Name: "target",
				},
				Spec: corev1.PodSpec{
					Containers: []corev1.Container{
						{
							Name: "debugger",
						},
					},
					NodeName: "node-1",
				},
			},
			expected: &corev1.Pod{
				ObjectMeta: metav1.ObjectMeta{
					Name: "debugger",
				},
				Spec: corev1.PodSpec{
					Containers: []corev1.Container{
						{
							Name:                     "debugger",
							Image:                    "busybox",
							ImagePullPolicy:          corev1.PullIfNotPresent,
							TerminationMessagePolicy: corev1.TerminationMessageReadFile,
						},
					},
				},
			},
		},
		{
			name: "same node",
			opts: &DebugOptions{
				CopyTo:     "debugger",
				Container:  "debugger",
				Image:      "busybox",
				PullPolicy: corev1.PullIfNotPresent,
				SameNode:   true,
			},
			pod: &corev1.Pod{
				ObjectMeta: metav1.ObjectMeta{
					Name: "target",
				},
				Spec: corev1.PodSpec{
					Containers: []corev1.Container{
						{
							Name: "debugger",
						},
					},
					NodeName: "node-1",
				},
			},
			expected: &corev1.Pod{
				ObjectMeta: metav1.ObjectMeta{
					Name: "debugger",
				},
				Spec: corev1.PodSpec{
					Containers: []corev1.Container{
						{
							Name:                     "debugger",
							Image:                    "busybox",
							ImagePullPolicy:          corev1.PullIfNotPresent,
							TerminationMessagePolicy: corev1.TerminationMessageReadFile,
						},
					},
					NodeName: "node-1",
				},
			},
		},
		{
			name: "metadata stripping",
			opts: &DebugOptions{
				CopyTo:     "debugger",
				Container:  "debugger",
				Image:      "busybox",
				PullPolicy: corev1.PullIfNotPresent,
			},
			pod: &corev1.Pod{
				ObjectMeta: metav1.ObjectMeta{
					Name: "target",
					Labels: map[string]string{
						"app": "business",
					},
					Annotations: map[string]string{
						"test": "test",
					},
					ResourceVersion:   "1",
					CreationTimestamp: metav1.Time{time.Now()},
				},
				Spec: corev1.PodSpec{
					Containers: []corev1.Container{
						{
							Name: "debugger",
						},
					},
				},
			},
			expected: &corev1.Pod{
				ObjectMeta: metav1.ObjectMeta{
					Name: "debugger",
					Annotations: map[string]string{
						"test": "test",
					},
				},
				Spec: corev1.PodSpec{
					Containers: []corev1.Container{
						{
							Name:                     "debugger",
							Image:                    "busybox",
							ImagePullPolicy:          corev1.PullIfNotPresent,
							TerminationMessagePolicy: corev1.TerminationMessageReadFile,
						},
					},
				},
			},
		},
		{
			name: "add a debug container",
			opts: &DebugOptions{
				CopyTo:     "debugger",
				Container:  "debugger",
				Image:      "busybox",
				PullPolicy: corev1.PullIfNotPresent,
			},
			pod: &corev1.Pod{
				ObjectMeta: metav1.ObjectMeta{
					Name: "target",
				},
				Spec: corev1.PodSpec{
					Containers: []corev1.Container{
						{
							Name: "business",
						},
					},
				},
			},
			expected: &corev1.Pod{
				ObjectMeta: metav1.ObjectMeta{
					Name: "debugger",
				},
				Spec: corev1.PodSpec{
					Containers: []corev1.Container{
						{
							Name: "business",
						},
						{
							Name:                     "debugger",
							Image:                    "busybox",
							ImagePullPolicy:          corev1.PullIfNotPresent,
							TerminationMessagePolicy: corev1.TerminationMessageReadFile,
						},
					},
				},
			},
		},
		{
			name: "customize envs",
			opts: &DebugOptions{
				CopyTo:     "debugger",
				Container:  "debugger",
				Image:      "busybox",
				PullPolicy: corev1.PullIfNotPresent,
				Env: []corev1.EnvVar{{
					Name:  "TEST",
					Value: "test",
				}},
			},
			pod: &corev1.Pod{
				ObjectMeta: metav1.ObjectMeta{
					Name: "target",
				},
				Spec: corev1.PodSpec{
					Containers: []corev1.Container{
						{
							Name: "business",
						},
					},
				},
			},
			expected: &corev1.Pod{
				ObjectMeta: metav1.ObjectMeta{
					Name: "debugger",
				},
				Spec: corev1.PodSpec{
					Containers: []corev1.Container{
						{
							Name: "business",
						},
						{
							Name:                     "debugger",
							Image:                    "busybox",
							ImagePullPolicy:          corev1.PullIfNotPresent,
							TerminationMessagePolicy: corev1.TerminationMessageReadFile,
							Env: []corev1.EnvVar{{
								Name:  "TEST",
								Value: "test",
							}},
						},
					},
				},
			},
		},
		{
			name: "debug args as container command",
			opts: &DebugOptions{
				CopyTo:     "debugger",
				Container:  "debugger",
				Args:       []string{"/bin/echo", "one", "two", "three"},
				Image:      "busybox",
				PullPolicy: corev1.PullIfNotPresent,
			},
			pod: &corev1.Pod{
				ObjectMeta: metav1.ObjectMeta{
					Name: "target",
				},
				Spec: corev1.PodSpec{
					Containers: []corev1.Container{
						{
							Name: "business",
						},
					},
				},
			},
			expected: &corev1.Pod{
				ObjectMeta: metav1.ObjectMeta{
					Name: "debugger",
				},
				Spec: corev1.PodSpec{
					Containers: []corev1.Container{
						{
							Name: "business",
						},
						{
							Name:                     "debugger",
							Image:                    "busybox",
							Command:                  []string{"/bin/echo", "one", "two", "three"},
							ImagePullPolicy:          corev1.PullIfNotPresent,
							TerminationMessagePolicy: corev1.TerminationMessageReadFile,
						},
					},
				},
			},
		},
		{
			name: "debug args as container command",
			opts: &DebugOptions{
				CopyTo:     "debugger",
				Container:  "debugger",
				Args:       []string{"one", "two", "three"},
				ArgsOnly:   true,
				Image:      "busybox",
				PullPolicy: corev1.PullIfNotPresent,
			},
			pod: &corev1.Pod{
				ObjectMeta: metav1.ObjectMeta{
					Name: "target",
				},
				Spec: corev1.PodSpec{
					Containers: []corev1.Container{
						{
							Name: "business",
						},
					},
				},
			},
			expected: &corev1.Pod{
				ObjectMeta: metav1.ObjectMeta{
					Name: "debugger",
				},
				Spec: corev1.PodSpec{
					Containers: []corev1.Container{
						{
							Name: "business",
						},
						{
							Name:                     "debugger",
							Image:                    "busybox",
							Args:                     []string{"one", "two", "three"},
							ImagePullPolicy:          corev1.PullIfNotPresent,
							TerminationMessagePolicy: corev1.TerminationMessageReadFile,
						},
					},
				},
			},
		},
		{
			name: "modify existing command to debug args",
			opts: &DebugOptions{
				CopyTo:     "debugger",
				Container:  "debugger",
				Args:       []string{"sleep", "1d"},
				Image:      "busybox",
				PullPolicy: corev1.PullIfNotPresent,
			},
			pod: &corev1.Pod{
				ObjectMeta: metav1.ObjectMeta{
					Name: "target",
				},
				Spec: corev1.PodSpec{
					Containers: []corev1.Container{
						{
							Name:    "debugger",
							Command: []string{"echo"},
							Args:    []string{"one", "two", "three"},
						},
					},
				},
			},
			expected: &corev1.Pod{
				ObjectMeta: metav1.ObjectMeta{
					Name: "debugger",
				},
				Spec: corev1.PodSpec{
					Containers: []corev1.Container{
						{
							Name:                     "debugger",
							Image:                    "busybox",
							Command:                  []string{"sleep", "1d"},
							ImagePullPolicy:          corev1.PullIfNotPresent,
							TerminationMessagePolicy: corev1.TerminationMessageReadFile,
						},
					},
				},
			},
		},
		{
			name: "random name",
			opts: &DebugOptions{
				CopyTo:     "debugger",
				Image:      "busybox",
				PullPolicy: corev1.PullIfNotPresent,
			},
			pod: &corev1.Pod{
				ObjectMeta: metav1.ObjectMeta{
					Name: "target",
				},
				Spec: corev1.PodSpec{
					Containers: []corev1.Container{
						{
							Name: "business",
						},
					},
				},
			},
			expected: &corev1.Pod{
				ObjectMeta: metav1.ObjectMeta{
					Name: "debugger",
				},
				Spec: corev1.PodSpec{
					Containers: []corev1.Container{
						{
							Name: "business",
						},
						{
							Name:                     "debugger-1",
							Image:                    "busybox",
							ImagePullPolicy:          corev1.PullIfNotPresent,
							TerminationMessagePolicy: corev1.TerminationMessageReadFile,
						},
					},
				},
			},
		},
		{
			name: "random name collision",
			opts: &DebugOptions{
				CopyTo:     "debugger",
				Image:      "busybox",
				PullPolicy: corev1.PullIfNotPresent,
			},
			pod: &corev1.Pod{
				ObjectMeta: metav1.ObjectMeta{
					Name: "target",
				},
				Spec: corev1.PodSpec{
					Containers: []corev1.Container{
						{
							Name: "debugger-1",
						},
					},
				},
			},
			expected: &corev1.Pod{
				ObjectMeta: metav1.ObjectMeta{
					Name: "debugger",
				},
				Spec: corev1.PodSpec{
					Containers: []corev1.Container{
						{
							Name: "debugger-1",
						},
						{
							Name:                     "debugger-2",
							Image:                    "busybox",
							ImagePullPolicy:          corev1.PullIfNotPresent,
							TerminationMessagePolicy: corev1.TerminationMessageReadFile,
						},
					},
				},
			},
		},
		{
			name: "shared process namespace",
			opts: &DebugOptions{
				CopyTo:                "debugger",
				Container:             "debugger",
				Image:                 "busybox",
				PullPolicy:            corev1.PullIfNotPresent,
				ShareProcesses:        true,
				shareProcessedChanged: true,
			},
			pod: &corev1.Pod{
				ObjectMeta: metav1.ObjectMeta{
					Name: "target",
				},
				Spec: corev1.PodSpec{
					Containers: []corev1.Container{
						{
							Name: "debugger",
						},
					},
					NodeName: "node-1",
				},
			},
			expected: &corev1.Pod{
				ObjectMeta: metav1.ObjectMeta{
					Name: "debugger",
				},
				Spec: corev1.PodSpec{
					Containers: []corev1.Container{
						{
							Name:                     "debugger",
							Image:                    "busybox",
							ImagePullPolicy:          corev1.PullIfNotPresent,
							TerminationMessagePolicy: corev1.TerminationMessageReadFile,
						},
					},
					ShareProcessNamespace: pointer.BoolPtr(true),
				},
			},
		},
	} {
		t.Run(tc.name, func(t *testing.T) {
			tc.opts.IOStreams = genericclioptions.NewTestIOStreamsDiscard()
			suffixCounter = 0

			if tc.pod == nil {
				tc.pod = &corev1.Pod{}
			}
			pod, _ := tc.opts.generatePodCopyWithDebugContainer(tc.pod)
			if diff := cmp.Diff(tc.expected, pod); diff != "" {
				t.Error("unexpected diff in generated object: (-want +got):\n", diff)
			}
		})
	}
}