/*
Copyright 2024 The Karmada 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 detector

import (
	"fmt"
	"testing"
	"time"

	appsv1 "k8s.io/api/apps/v1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/runtime"
	"k8s.io/apimachinery/pkg/runtime/schema"
	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
	dynamicfake "k8s.io/client-go/dynamic/fake"
	clientgoscheme "k8s.io/client-go/kubernetes/scheme"
	"k8s.io/utils/ptr"
	"sigs.k8s.io/controller-runtime/pkg/client"
	"sigs.k8s.io/controller-runtime/pkg/client/fake"

	policyv1alpha1 "github.com/karmada-io/karmada/pkg/apis/policy/v1alpha1"
	"github.com/karmada-io/karmada/pkg/apis/work/v1alpha2"
	"github.com/karmada-io/karmada/pkg/util/fedinformer/genericmanager"
)

type MockAsyncWorker struct {
	queue []interface{}
}

// Note: This is a dummy implementation of Add for testing purposes.
func (m *MockAsyncWorker) Add(item interface{}) {
	// No actual work is done in the mock; we just simulate running
	m.queue = append(m.queue, item)
}

// Note: This is a dummy implementation of AddAfter for testing purposes.
func (m *MockAsyncWorker) AddAfter(item interface{}, duration time.Duration) {
	// No actual work is done in the mock; we just simulate running
	fmt.Printf("%v", duration)
	m.queue = append(m.queue, item)
}

// Note: This is a dummy implementation of Enqueue for testing purposes.
func (m *MockAsyncWorker) Enqueue(obj interface{}) {
	// Assuming KeyFunc is used to generate a key; for simplicity, we use obj directly
	m.queue = append(m.queue, obj)
}

// Note: This is a dummy implementation of Run for testing purposes.
func (m *MockAsyncWorker) Run(workerNumber int, stopChan <-chan struct{}) {
	// No actual work is done in the mock; we just simulate running
	fmt.Printf("%v", workerNumber)
	fmt.Printf("%v", <-stopChan)
}

// GetQueue returns the current state of the queue
func (m *MockAsyncWorker) GetQueue() []interface{} {
	return m.queue
}

func TestHandleDeprioritizedPropagationPolicy(t *testing.T) {
	scheme := runtime.NewScheme()
	utilruntime.Must(clientgoscheme.AddToScheme(scheme))
	utilruntime.Must(appsv1.AddToScheme(scheme))
	utilruntime.Must(v1alpha2.Install(scheme))
	utilruntime.Must(policyv1alpha1.Install(scheme))

	propagationPolicyGVR := schema.GroupVersionResource{
		Group:    policyv1alpha1.GroupVersion.Group,
		Version:  policyv1alpha1.GroupVersion.Version,
		Resource: policyv1alpha1.ResourcePluralPropagationPolicy,
	}

	tests := []struct {
		name          string
		newPolicy     *policyv1alpha1.PropagationPolicy
		oldPolicy     *policyv1alpha1.PropagationPolicy
		objects       []runtime.Object
		setupClient   func() *fake.ClientBuilder
		wantQueueSize int
	}{
		{
			name: "preempt deprioritized propagation policy of len 1",
			newPolicy: &policyv1alpha1.PropagationPolicy{
				ObjectMeta: metav1.ObjectMeta{Name: "app", Namespace: "test"},
				Spec: policyv1alpha1.PropagationSpec{
					Priority: ptr.To[int32](2),
					ResourceSelectors: []policyv1alpha1.ResourceSelector{
						{
							APIVersion:    "apps/v1",
							Kind:          "Deployment",
							Namespace:     "test",
							LabelSelector: &metav1.LabelSelector{MatchLabels: map[string]string{"app": "nginx"}},
						},
					},
				},
			},
			oldPolicy: &policyv1alpha1.PropagationPolicy{
				ObjectMeta: metav1.ObjectMeta{Name: "app", Namespace: "test"},
				Spec: policyv1alpha1.PropagationSpec{
					Priority: ptr.To[int32](4),
					ResourceSelectors: []policyv1alpha1.ResourceSelector{
						{
							APIVersion:    "apps/v1",
							Kind:          "Deployment",
							Namespace:     "test",
							LabelSelector: &metav1.LabelSelector{MatchLabels: map[string]string{"app": "nginx"}},
						},
					},
				},
			},
			objects: []runtime.Object{
				&policyv1alpha1.PropagationPolicy{
					ObjectMeta: metav1.ObjectMeta{
						Name:      "foo",
						Namespace: "test",
						Labels: map[string]string{
							policyv1alpha1.PropagationPolicyPermanentIDLabel: "policy-1",
						},
					},
					Spec: policyv1alpha1.PropagationSpec{
						Priority:   ptr.To[int32](3),
						Preemption: policyv1alpha1.PreemptAlways,
						ResourceSelectors: []policyv1alpha1.ResourceSelector{
							{
								APIVersion: "apps/v1",
								Kind:       "Deployment",
								Namespace:  "test",
								Name:       "default",
							},
						},
					},
				},
			},
			setupClient: func() *fake.ClientBuilder {
				obj := &policyv1alpha1.PropagationPolicy{
					ObjectMeta: metav1.ObjectMeta{
						Name:      "foo",
						Namespace: "test",
						Labels: map[string]string{
							policyv1alpha1.PropagationPolicyPermanentIDLabel: "policy-1",
						},
					},
					Spec: policyv1alpha1.PropagationSpec{
						Priority:   ptr.To[int32](3),
						Preemption: policyv1alpha1.PreemptAlways,
						ResourceSelectors: []policyv1alpha1.ResourceSelector{
							{
								APIVersion: "apps/v1",
								Kind:       "Deployment",
								Namespace:  "test",
								Name:       "default",
							},
						},
					},
				}
				return fake.NewClientBuilder().WithScheme(scheme).WithObjects(obj)
			},
			wantQueueSize: 1,
		},
		{
			name: "preempt deprioritized propagation policy of len 2",
			newPolicy: &policyv1alpha1.PropagationPolicy{
				ObjectMeta: metav1.ObjectMeta{Name: "app", Namespace: "test"},
				Spec: policyv1alpha1.PropagationSpec{
					Priority: ptr.To[int32](2),
					ResourceSelectors: []policyv1alpha1.ResourceSelector{
						{
							APIVersion:    "apps/v1",
							Kind:          "Deployment",
							Namespace:     "test",
							LabelSelector: &metav1.LabelSelector{MatchLabels: map[string]string{"app": "nginx"}},
						},
					},
				},
			},
			oldPolicy: &policyv1alpha1.PropagationPolicy{
				ObjectMeta: metav1.ObjectMeta{Name: "app", Namespace: "test"},
				Spec: policyv1alpha1.PropagationSpec{
					Priority: ptr.To[int32](5),
					ResourceSelectors: []policyv1alpha1.ResourceSelector{
						{
							APIVersion:    "apps/v1",
							Kind:          "Deployment",
							Namespace:     "test",
							LabelSelector: &metav1.LabelSelector{MatchLabels: map[string]string{"app": "nginx"}},
						},
					},
				},
			},
			objects: []runtime.Object{
				&policyv1alpha1.PropagationPolicy{
					ObjectMeta: metav1.ObjectMeta{
						Name:      "foo",
						Namespace: "test",
						Labels: map[string]string{
							policyv1alpha1.PropagationPolicyPermanentIDLabel: "policy-1",
						},
					},
					Spec: policyv1alpha1.PropagationSpec{
						Priority:   ptr.To[int32](3),
						Preemption: policyv1alpha1.PreemptAlways,
						ResourceSelectors: []policyv1alpha1.ResourceSelector{
							{
								APIVersion: "apps/v1",
								Kind:       "Deployment",
								Namespace:  "test",
								Name:       "default",
							},
						},
					},
				},
				&policyv1alpha1.PropagationPolicy{
					ObjectMeta: metav1.ObjectMeta{
						Name:      "foo-2",
						Namespace: "test",
						Labels: map[string]string{
							policyv1alpha1.PropagationPolicyPermanentIDLabel: "policy-2",
						},
					},
					Spec: policyv1alpha1.PropagationSpec{
						Priority:   ptr.To[int32](4),
						Preemption: policyv1alpha1.PreemptAlways,
						ResourceSelectors: []policyv1alpha1.ResourceSelector{
							{
								APIVersion: "apps/v1",
								Kind:       "Deployment",
								Namespace:  "test-2",
								Name:       "default-2",
							},
						},
					},
				},
			},
			setupClient: func() *fake.ClientBuilder {
				obj := []client.Object{
					&policyv1alpha1.PropagationPolicy{
						ObjectMeta: metav1.ObjectMeta{
							Name:      "foo",
							Namespace: "test",
							Labels: map[string]string{
								policyv1alpha1.PropagationPolicyPermanentIDLabel: "policy-1",
							},
						},
						Spec: policyv1alpha1.PropagationSpec{
							Priority:   ptr.To[int32](3),
							Preemption: policyv1alpha1.PreemptAlways,
							ResourceSelectors: []policyv1alpha1.ResourceSelector{
								{
									APIVersion: "apps/v1",
									Kind:       "Deployment",
									Namespace:  "test",
									Name:       "default",
								},
							},
						},
					},
					&policyv1alpha1.PropagationPolicy{
						ObjectMeta: metav1.ObjectMeta{
							Name:      "foo-2",
							Namespace: "test",
							Labels: map[string]string{
								policyv1alpha1.PropagationPolicyPermanentIDLabel: "policy-2",
							},
						},
						Spec: policyv1alpha1.PropagationSpec{
							Priority:   ptr.To[int32](4),
							Preemption: policyv1alpha1.PreemptAlways,
							ResourceSelectors: []policyv1alpha1.ResourceSelector{
								{
									APIVersion: "apps/v1",
									Kind:       "Deployment",
									Namespace:  "test-2",
									Name:       "default-2",
								},
							},
						},
					},
				}
				return fake.NewClientBuilder().WithScheme(scheme).WithObjects(obj...)
			},
			wantQueueSize: 2,
		},
		{
			name: "no policy to preempt",
			newPolicy: &policyv1alpha1.PropagationPolicy{
				ObjectMeta: metav1.ObjectMeta{Name: "app", Namespace: "test"},
				Spec: policyv1alpha1.PropagationSpec{
					Priority: ptr.To[int32](2),
					ResourceSelectors: []policyv1alpha1.ResourceSelector{
						{
							APIVersion:    "apps/v1",
							Kind:          "Deployment",
							Namespace:     "test",
							LabelSelector: &metav1.LabelSelector{MatchLabels: map[string]string{"app": "nginx"}},
						},
					},
				},
			},
			oldPolicy: &policyv1alpha1.PropagationPolicy{
				ObjectMeta: metav1.ObjectMeta{Name: "app", Namespace: "test"},
				Spec: policyv1alpha1.PropagationSpec{
					Priority: ptr.To[int32](4),
					ResourceSelectors: []policyv1alpha1.ResourceSelector{
						{
							APIVersion:    "apps/v1",
							Kind:          "Deployment",
							Namespace:     "test",
							LabelSelector: &metav1.LabelSelector{MatchLabels: map[string]string{"app": "nginx"}},
						},
					},
				},
			},
			objects: nil,
			setupClient: func() *fake.ClientBuilder {
				return fake.NewClientBuilder().WithScheme(scheme)
			},
			wantQueueSize: 0,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			fakeClient := tt.setupClient().Build()
			stopCh := make(chan struct{})
			defer close(stopCh)
			fakeDynamicClient := dynamicfake.NewSimpleDynamicClient(scheme, tt.objects...)
			genMgr := genericmanager.NewSingleClusterInformerManager(fakeDynamicClient, 0, stopCh)
			resourceDetector := &ResourceDetector{
				Client:                  fakeClient,
				DynamicClient:           fakeDynamicClient,
				InformerManager:         genMgr,
				propagationPolicyLister: genMgr.Lister(propagationPolicyGVR),
			}
			mockWorker := &MockAsyncWorker{}
			resourceDetector.policyReconcileWorker = mockWorker
			resourceDetector.InformerManager.Start()
			resourceDetector.InformerManager.WaitForCacheSync()

			resourceDetector.HandleDeprioritizedPropagationPolicy(*tt.oldPolicy, *tt.newPolicy)

			gotQueueSize := len(mockWorker.GetQueue())
			if gotQueueSize != tt.wantQueueSize {
				t.Errorf("HandleDeprioritizedPropagationPolicy() want queue size %v, got %v", tt.wantQueueSize, gotQueueSize)
			}
		})
	}
}

func TestHandleDeprioritizedClusterPropagationPolicy(t *testing.T) {
	scheme := runtime.NewScheme()
	utilruntime.Must(clientgoscheme.AddToScheme(scheme))
	utilruntime.Must(appsv1.AddToScheme(scheme))
	utilruntime.Must(v1alpha2.Install(scheme))
	utilruntime.Must(policyv1alpha1.Install(scheme))

	clusterPropagationPolicyGVR := schema.GroupVersionResource{
		Group:    policyv1alpha1.GroupVersion.Group,
		Version:  policyv1alpha1.GroupVersion.Version,
		Resource: policyv1alpha1.ResourcePluralClusterPropagationPolicy,
	}

	tests := []struct {
		name          string
		newPolicy     *policyv1alpha1.ClusterPropagationPolicy
		oldPolicy     *policyv1alpha1.ClusterPropagationPolicy
		objects       []runtime.Object
		setupClient   func() *fake.ClientBuilder
		wantQueueSize int
	}{
		{
			name: "preempt deprioritized cluster propagation policy of len 1",
			newPolicy: &policyv1alpha1.ClusterPropagationPolicy{
				ObjectMeta: metav1.ObjectMeta{Name: "app", Namespace: "test"},
				Spec: policyv1alpha1.PropagationSpec{
					Priority: ptr.To[int32](2),
					ResourceSelectors: []policyv1alpha1.ResourceSelector{
						{
							APIVersion:    "apps/v1",
							Kind:          "Deployment",
							Namespace:     "test",
							LabelSelector: &metav1.LabelSelector{MatchLabels: map[string]string{"app": "nginx"}},
						},
					},
				},
			},
			oldPolicy: &policyv1alpha1.ClusterPropagationPolicy{
				ObjectMeta: metav1.ObjectMeta{Name: "app", Namespace: "test"},
				Spec: policyv1alpha1.PropagationSpec{
					Priority: ptr.To[int32](4),
					ResourceSelectors: []policyv1alpha1.ResourceSelector{
						{
							APIVersion:    "apps/v1",
							Kind:          "Deployment",
							Namespace:     "test",
							LabelSelector: &metav1.LabelSelector{MatchLabels: map[string]string{"app": "nginx"}},
						},
					},
				},
			},
			objects: []runtime.Object{
				&policyv1alpha1.ClusterPropagationPolicy{
					ObjectMeta: metav1.ObjectMeta{
						Name:      "foo",
						Namespace: "bar",
						Labels: map[string]string{
							policyv1alpha1.ClusterPropagationPolicyPermanentIDLabel: "policy-1",
						},
					},
					Spec: policyv1alpha1.PropagationSpec{
						Priority:   ptr.To[int32](3),
						Preemption: policyv1alpha1.PreemptAlways,
						ResourceSelectors: []policyv1alpha1.ResourceSelector{
							{
								APIVersion: "apps/v1",
								Kind:       "Deployment",
								Namespace:  "test",
								Name:       "default",
							},
						},
					},
				},
			},
			setupClient: func() *fake.ClientBuilder {
				obj := &policyv1alpha1.ClusterPropagationPolicy{
					ObjectMeta: metav1.ObjectMeta{
						Name:      "foo",
						Namespace: "bar",
						Labels: map[string]string{
							policyv1alpha1.ClusterPropagationPolicyPermanentIDLabel: "policy-1",
						},
					},
					Spec: policyv1alpha1.PropagationSpec{
						Priority:   ptr.To[int32](3),
						Preemption: policyv1alpha1.PreemptAlways,
						ResourceSelectors: []policyv1alpha1.ResourceSelector{
							{
								APIVersion: "apps/v1",
								Kind:       "Deployment",
								Namespace:  "test",
								Name:       "default",
							},
						},
					},
				}
				return fake.NewClientBuilder().WithScheme(scheme).WithObjects(obj)
			},
			wantQueueSize: 1,
		},
		{
			name: "preempt deprioritized cluster propagation policy of len 2",
			newPolicy: &policyv1alpha1.ClusterPropagationPolicy{
				ObjectMeta: metav1.ObjectMeta{Name: "app", Namespace: "test"},
				Spec: policyv1alpha1.PropagationSpec{
					Priority: ptr.To[int32](2),
					ResourceSelectors: []policyv1alpha1.ResourceSelector{
						{
							APIVersion:    "apps/v1",
							Kind:          "Deployment",
							Namespace:     "test",
							LabelSelector: &metav1.LabelSelector{MatchLabels: map[string]string{"app": "nginx"}},
						},
					},
				},
			},
			oldPolicy: &policyv1alpha1.ClusterPropagationPolicy{
				ObjectMeta: metav1.ObjectMeta{Name: "app", Namespace: "test"},
				Spec: policyv1alpha1.PropagationSpec{
					Priority: ptr.To[int32](5),
					ResourceSelectors: []policyv1alpha1.ResourceSelector{
						{
							APIVersion:    "apps/v1",
							Kind:          "Deployment",
							Namespace:     "test",
							LabelSelector: &metav1.LabelSelector{MatchLabels: map[string]string{"app": "nginx"}},
						},
					},
				},
			},
			objects: []runtime.Object{
				&policyv1alpha1.ClusterPropagationPolicy{
					ObjectMeta: metav1.ObjectMeta{
						Name:      "foo",
						Namespace: "bar",
						Labels: map[string]string{
							policyv1alpha1.ClusterPropagationPolicyPermanentIDLabel: "policy-1",
						},
					},
					Spec: policyv1alpha1.PropagationSpec{
						Priority:   ptr.To[int32](3),
						Preemption: policyv1alpha1.PreemptAlways,
						ResourceSelectors: []policyv1alpha1.ResourceSelector{
							{
								APIVersion: "apps/v1",
								Kind:       "Deployment",
								Namespace:  "test",
								Name:       "default",
							},
						},
					},
				},
				&policyv1alpha1.ClusterPropagationPolicy{
					ObjectMeta: metav1.ObjectMeta{
						Name:      "foo-2",
						Namespace: "bar-2",
						Labels: map[string]string{
							policyv1alpha1.ClusterPropagationPolicyPermanentIDLabel: "policy-2",
						},
					},
					Spec: policyv1alpha1.PropagationSpec{
						Priority:   ptr.To[int32](4),
						Preemption: policyv1alpha1.PreemptAlways,
						ResourceSelectors: []policyv1alpha1.ResourceSelector{
							{
								APIVersion: "apps/v1",
								Kind:       "Deployment",
								Namespace:  "test-2",
								Name:       "default-2",
							},
						},
					},
				},
			},
			setupClient: func() *fake.ClientBuilder {
				obj := []client.Object{
					&policyv1alpha1.ClusterPropagationPolicy{
						ObjectMeta: metav1.ObjectMeta{
							Name:      "foo",
							Namespace: "bar",
							Labels: map[string]string{
								policyv1alpha1.ClusterPropagationPolicyPermanentIDLabel: "policy-1",
							},
						},
						Spec: policyv1alpha1.PropagationSpec{
							Priority:   ptr.To[int32](3),
							Preemption: policyv1alpha1.PreemptAlways,
							ResourceSelectors: []policyv1alpha1.ResourceSelector{
								{
									APIVersion: "apps/v1",
									Kind:       "Deployment",
									Namespace:  "test",
									Name:       "default",
								},
							},
						},
					},
					&policyv1alpha1.ClusterPropagationPolicy{
						ObjectMeta: metav1.ObjectMeta{
							Name:      "foo-2",
							Namespace: "bar-2",
							Labels: map[string]string{
								policyv1alpha1.ClusterPropagationPolicyPermanentIDLabel: "policy-2",
							},
						},
						Spec: policyv1alpha1.PropagationSpec{
							Priority:   ptr.To[int32](4),
							Preemption: policyv1alpha1.PreemptAlways,
							ResourceSelectors: []policyv1alpha1.ResourceSelector{
								{
									APIVersion: "apps/v1",
									Kind:       "Deployment",
									Namespace:  "test-2",
									Name:       "default-2",
								},
							},
						},
					},
				}
				return fake.NewClientBuilder().WithScheme(scheme).WithObjects(obj...)
			},
			wantQueueSize: 2,
		},
		{
			name: "no cluster policy to preempt",
			newPolicy: &policyv1alpha1.ClusterPropagationPolicy{
				ObjectMeta: metav1.ObjectMeta{Name: "app", Namespace: "test"},
				Spec: policyv1alpha1.PropagationSpec{
					Priority: ptr.To[int32](2),
					ResourceSelectors: []policyv1alpha1.ResourceSelector{
						{
							APIVersion:    "apps/v1",
							Kind:          "Deployment",
							Namespace:     "test",
							LabelSelector: &metav1.LabelSelector{MatchLabels: map[string]string{"app": "nginx"}},
						},
					},
				},
			},
			oldPolicy: &policyv1alpha1.ClusterPropagationPolicy{
				ObjectMeta: metav1.ObjectMeta{Name: "app", Namespace: "test"},
				Spec: policyv1alpha1.PropagationSpec{
					Priority: ptr.To[int32](4),
					ResourceSelectors: []policyv1alpha1.ResourceSelector{
						{
							APIVersion:    "apps/v1",
							Kind:          "Deployment",
							Namespace:     "test",
							LabelSelector: &metav1.LabelSelector{MatchLabels: map[string]string{"app": "nginx"}},
						},
					},
				},
			},
			objects: nil,
			setupClient: func() *fake.ClientBuilder {
				return fake.NewClientBuilder().WithScheme(scheme)
			},
			wantQueueSize: 0,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			fakeClient := tt.setupClient().Build()
			stopCh := make(chan struct{})
			defer close(stopCh)
			fakeDynamicClient := dynamicfake.NewSimpleDynamicClient(scheme, tt.objects...)
			genMgr := genericmanager.NewSingleClusterInformerManager(fakeDynamicClient, 0, stopCh)
			resourceDetector := &ResourceDetector{
				Client:                         fakeClient,
				DynamicClient:                  fakeDynamicClient,
				InformerManager:                genMgr,
				clusterPropagationPolicyLister: genMgr.Lister(clusterPropagationPolicyGVR),
			}
			mockWorker := &MockAsyncWorker{}
			resourceDetector.clusterPolicyReconcileWorker = mockWorker
			resourceDetector.InformerManager.Start()
			resourceDetector.InformerManager.WaitForCacheSync()

			resourceDetector.HandleDeprioritizedClusterPropagationPolicy(*tt.oldPolicy, *tt.newPolicy)

			gotQueueSize := len(mockWorker.GetQueue())
			if gotQueueSize != tt.wantQueueSize {
				t.Errorf("HandleDeprioritizedClusterPropagationPolicy() want queue size %v, got %v", tt.wantQueueSize, gotQueueSize)
			}
		})
	}
}