/*
Copyright 2021 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 util

import (
	"reflect"
	"testing"
	"time"

	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/util/sets"

	policyv1alpha1 "github.com/karmada-io/karmada/pkg/apis/policy/v1alpha1"
	workv1alpha2 "github.com/karmada-io/karmada/pkg/apis/work/v1alpha2"
	testhelper "github.com/karmada-io/karmada/test/helper"
)

const (
	ClusterMember1 = "member1"
	ClusterMember2 = "member2"
)

func TestGetBindingClusterNames(t *testing.T) {
	tests := []struct {
		name     string
		binding  *workv1alpha2.ResourceBinding
		expected []string
	}{
		{
			name: "nil",
			binding: &workv1alpha2.ResourceBinding{
				ObjectMeta: metav1.ObjectMeta{
					Name:      "demo-name",
					Namespace: "demo-ns",
				},
				Spec: workv1alpha2.ResourceBindingSpec{
					Clusters: []workv1alpha2.TargetCluster{},
				},
				Status: workv1alpha2.ResourceBindingStatus{},
			},
			expected: nil,
		},
		{
			name: "not nil",
			binding: &workv1alpha2.ResourceBinding{
				ObjectMeta: metav1.ObjectMeta{
					Name:      "demo-name",
					Namespace: "demo-ns",
				},
				Spec: workv1alpha2.ResourceBindingSpec{
					Clusters: []workv1alpha2.TargetCluster{
						{
							Name: ClusterMember1,
						},
						{
							Name: ClusterMember2,
						},
					},
				},
				Status: workv1alpha2.ResourceBindingStatus{},
			},
			expected: []string{ClusterMember1, ClusterMember2},
		},
	}

	for i := range tests {
		t.Run(tests[i].name, func(t *testing.T) {
			got := GetBindingClusterNames(&tests[i].binding.Spec)
			if !reflect.DeepEqual(got, tests[i].expected) {
				t.Errorf("GetBindingClusterNames() = %v, want %v", got, tests[i].expected)
			}
		})
	}
}

func TestIsBindingReplicasChanged(t *testing.T) {
	tests := []struct {
		name        string
		bindingSpec *workv1alpha2.ResourceBindingSpec
		strategy    *policyv1alpha1.ReplicaSchedulingStrategy
		expected    bool
	}{
		{
			name:        "nil strategy",
			bindingSpec: &workv1alpha2.ResourceBindingSpec{},
			strategy:    nil,
			expected:    false,
		},
		{
			name:        "empty strategy",
			bindingSpec: &workv1alpha2.ResourceBindingSpec{},
			strategy:    &policyv1alpha1.ReplicaSchedulingStrategy{},
			expected:    false,
		},
		{
			name: "Duplicated strategy and replicas not changed",
			bindingSpec: &workv1alpha2.ResourceBindingSpec{
				Replicas: 5,
				Clusters: []workv1alpha2.TargetCluster{
					{
						Name:     ClusterMember1,
						Replicas: 5,
					},
					{
						Name:     ClusterMember2,
						Replicas: 5,
					},
				}},
			strategy: &policyv1alpha1.ReplicaSchedulingStrategy{ReplicaSchedulingType: policyv1alpha1.ReplicaSchedulingTypeDuplicated},
			expected: false,
		},
		{
			name: "Duplicated strategy and replicas changed",
			bindingSpec: &workv1alpha2.ResourceBindingSpec{
				Replicas: 5,
				Clusters: []workv1alpha2.TargetCluster{
					{
						Name:     ClusterMember1,
						Replicas: 3,
					},
					{
						Name:     ClusterMember2,
						Replicas: 5,
					},
				}},
			strategy: &policyv1alpha1.ReplicaSchedulingStrategy{ReplicaSchedulingType: policyv1alpha1.ReplicaSchedulingTypeDuplicated},
			expected: true,
		},
		{
			name: "Divided strategy and replicas not changed",
			bindingSpec: &workv1alpha2.ResourceBindingSpec{
				Replicas: 5,
				Clusters: []workv1alpha2.TargetCluster{
					{
						Name:     ClusterMember1,
						Replicas: 2,
					},
					{
						Name:     ClusterMember2,
						Replicas: 3,
					},
				},
			},
			strategy: &policyv1alpha1.ReplicaSchedulingStrategy{ReplicaSchedulingType: policyv1alpha1.ReplicaSchedulingTypeDivided},
			expected: false,
		},
		{
			name: "Divided strategy and replicas changed",
			bindingSpec: &workv1alpha2.ResourceBindingSpec{
				Replicas: 5,
				Clusters: []workv1alpha2.TargetCluster{
					{
						Name:     ClusterMember1,
						Replicas: 3,
					},
					{
						Name:     ClusterMember2,
						Replicas: 3,
					},
				},
			},
			strategy: &policyv1alpha1.ReplicaSchedulingStrategy{ReplicaSchedulingType: policyv1alpha1.ReplicaSchedulingTypeDivided},
			expected: true,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			if tt.bindingSpec == nil {
				t.FailNow()
			}
			got := IsBindingReplicasChanged(tt.bindingSpec, tt.strategy)
			if got != tt.expected {
				t.Errorf("IsBindingReplicasChanged() = %v, want %v", got, tt.expected)
			}
		})
	}
}

func TestGetSumOfReplicas(t *testing.T) {
	tests := []struct {
		name     string
		clusters []workv1alpha2.TargetCluster
		expected int32
	}{
		{
			name:     "empty",
			clusters: []workv1alpha2.TargetCluster{},
			expected: 0,
		},
		{
			name: "not empty",
			clusters: []workv1alpha2.TargetCluster{
				{
					Name:     ClusterMember1,
					Replicas: 2,
				},
				{
					Name:     ClusterMember2,
					Replicas: 3,
				},
			},
			expected: 5,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got := GetSumOfReplicas(tt.clusters)
			if got != tt.expected {
				t.Errorf("GetSumOfReplicas() = %v, want %v", got, tt.expected)
			}
		})
	}
}

func TestConvertToClusterNames(t *testing.T) {
	tests := []struct {
		name     string
		clusters []workv1alpha2.TargetCluster
		expected sets.Set[string]
	}{
		{
			name:     "empty",
			clusters: []workv1alpha2.TargetCluster{},
			expected: sets.New[string](),
		},
		{
			name: "not empty",
			clusters: []workv1alpha2.TargetCluster{
				{
					Name:     ClusterMember1,
					Replicas: 2,
				},
				{
					Name:     ClusterMember2,
					Replicas: 3,
				},
			},
			expected: sets.New(ClusterMember1, ClusterMember2),
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got := ConvertToClusterNames(tt.clusters)
			if !reflect.DeepEqual(got, tt.expected) {
				t.Errorf("ConvertToClusterNames() = %v, want %v", got, tt.expected)
			}
		})
	}
}

func TestMergeTargetClusters(t *testing.T) {
	tests := []struct {
		name     string
		old      []workv1alpha2.TargetCluster
		new      []workv1alpha2.TargetCluster
		expected []workv1alpha2.TargetCluster
	}{
		{
			name:     "empty",
			old:      []workv1alpha2.TargetCluster{},
			new:      []workv1alpha2.TargetCluster{},
			expected: []workv1alpha2.TargetCluster{},
		},
		{
			name: "old clusters are empty",
			old:  []workv1alpha2.TargetCluster{},
			new: []workv1alpha2.TargetCluster{
				{
					Name:     ClusterMember2,
					Replicas: 3,
				},
			},
			expected: []workv1alpha2.TargetCluster{
				{
					Name:     ClusterMember2,
					Replicas: 3,
				},
			},
		},
		{
			name: "new clusters are empty",
			old: []workv1alpha2.TargetCluster{
				{
					Name:     ClusterMember1,
					Replicas: 3,
				},
			},
			new: []workv1alpha2.TargetCluster{},
			expected: []workv1alpha2.TargetCluster{
				{
					Name:     ClusterMember1,
					Replicas: 3,
				},
			},
		},
		{
			name: "no cluster with the same name",
			old: []workv1alpha2.TargetCluster{
				{
					Name:     ClusterMember1,
					Replicas: 2,
				},
			},
			new: []workv1alpha2.TargetCluster{
				{
					Name:     ClusterMember2,
					Replicas: 3,
				},
			},
			expected: []workv1alpha2.TargetCluster{
				{
					Name:     ClusterMember1,
					Replicas: 2,
				},
				{
					Name:     ClusterMember2,
					Replicas: 3,
				},
			},
		},
		{
			name: "some clusters have the same name in the old and new clusters",
			old: []workv1alpha2.TargetCluster{
				{
					Name:     ClusterMember1,
					Replicas: 2,
				},
			},
			new: []workv1alpha2.TargetCluster{
				{
					Name:     ClusterMember1,
					Replicas: 4,
				},
				{
					Name:     ClusterMember2,
					Replicas: 3,
				},
			},
			expected: []workv1alpha2.TargetCluster{
				{
					Name:     ClusterMember1,
					Replicas: 6,
				},
				{
					Name:     ClusterMember2,
					Replicas: 3,
				},
			},
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got := MergeTargetClusters(tt.old, tt.new)
			if !testhelper.IsScheduleResultEqual(got, tt.expected) {
				t.Errorf("MergeTargetClusters() = %v, want %v", got, tt.expected)
			}
		})
	}
}

func TestRescheduleRequired(t *testing.T) {
	currentTime := metav1.Now()
	previousTime := metav1.Time{Time: time.Now().Add(-1 * time.Minute)}

	tests := []struct {
		name                  string
		rescheduleTriggeredAt *metav1.Time
		lastScheduledTime     *metav1.Time
		want                  bool
	}{
		{
			name:                  "rescheduleTriggeredAt is nil",
			rescheduleTriggeredAt: nil,
			lastScheduledTime:     &currentTime,
			want:                  false,
		},
		{
			name:                  "lastScheduledTime is nil",
			rescheduleTriggeredAt: &currentTime,
			lastScheduledTime:     nil,
			want:                  false,
		},
		{
			name:                  "rescheduleTriggeredAt is before than lastScheduledTime",
			rescheduleTriggeredAt: &previousTime,
			lastScheduledTime:     &currentTime,
			want:                  false,
		},
		{
			name:                  "rescheduleTriggeredAt is later than lastScheduledTime",
			rescheduleTriggeredAt: &currentTime,
			lastScheduledTime:     &previousTime,
			want:                  true,
		},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			if got := RescheduleRequired(tt.rescheduleTriggeredAt, tt.lastScheduledTime); got != tt.want {
				t.Errorf("RescheduleRequired() = %v, want %v", got, tt.want)
			}
		})
	}
}