/*
Copyright 2019 The Kubernetes Authors.
Copyright 2020 Authors of Arktos - file modified.

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.
*/

// File modified by backporting scheduler 1.18.5 from kubernetes on 05/04/2021
package podtopologyspread

import (
	"context"
	"testing"

	"github.com/google/go-cmp/cmp"
	appsv1 "k8s.io/api/apps/v1"
	v1 "k8s.io/api/core/v1"
	"k8s.io/apimachinery/pkg/runtime"
	"k8s.io/apimachinery/pkg/util/sets"
	"k8s.io/client-go/informers"
	"k8s.io/client-go/kubernetes/fake"
	framework "k8s.io/kubernetes/pkg/scheduler/framework/v1alpha1"
	"k8s.io/kubernetes/pkg/scheduler/internal/cache"
	st "k8s.io/kubernetes/pkg/scheduler/testing"
	"k8s.io/utils/pointer"
)

func TestPreScoreStateEmptyNodes(t *testing.T) {
	tests := []struct {
		name               string
		pod                *v1.Pod
		nodes              []*v1.Node
		objs               []runtime.Object
		defaultConstraints []v1.TopologySpreadConstraint
		want               *preScoreState
	}{
		{
			name: "normal case",
			pod: st.MakePod().Name("p").Label("foo", "").
				SpreadConstraint(1, "zone", v1.ScheduleAnyway, st.MakeLabelSelector().Exists("foo").Obj()).
				SpreadConstraint(1, "node", v1.ScheduleAnyway, st.MakeLabelSelector().Exists("foo").Obj()).
				Obj(),
			nodes: []*v1.Node{
				st.MakeNode().Name("node-a").Label("zone", "zone1").Label("node", "node-a").Obj(),
				st.MakeNode().Name("node-b").Label("zone", "zone1").Label("node", "node-b").Obj(),
				st.MakeNode().Name("node-x").Label("zone", "zone2").Label("node", "node-x").Obj(),
			},
			want: &preScoreState{
				Constraints: []topologySpreadConstraint{
					{
						MaxSkew:     1,
						TopologyKey: "zone",
						Selector:    mustConvertLabelSelectorAsSelector(t, st.MakeLabelSelector().Exists("foo").Obj()),
					},
					{
						MaxSkew:     1,
						TopologyKey: "node",
						Selector:    mustConvertLabelSelectorAsSelector(t, st.MakeLabelSelector().Exists("foo").Obj()),
					},
				},
				NodeNameSet: sets.NewString("node-a", "node-b", "node-x"),
				TopologyPairToPodCounts: map[topologyPair]*int64{
					{key: "zone", value: "zone1"}:  pointer.Int64Ptr(0),
					{key: "zone", value: "zone2"}:  pointer.Int64Ptr(0),
					{key: "node", value: "node-a"}: pointer.Int64Ptr(0),
					{key: "node", value: "node-b"}: pointer.Int64Ptr(0),
					{key: "node", value: "node-x"}: pointer.Int64Ptr(0),
				},
			},
		},
		{
			name: "node-x doesn't have label zone",
			pod: st.MakePod().Name("p").Label("foo", "").
				SpreadConstraint(1, "zone", v1.ScheduleAnyway, st.MakeLabelSelector().Exists("foo").Obj()).
				SpreadConstraint(1, "node", v1.ScheduleAnyway, st.MakeLabelSelector().Exists("bar").Obj()).
				Obj(),
			nodes: []*v1.Node{
				st.MakeNode().Name("node-a").Label("zone", "zone1").Label("node", "node-a").Obj(),
				st.MakeNode().Name("node-b").Label("zone", "zone1").Label("node", "node-b").Obj(),
				st.MakeNode().Name("node-x").Label("node", "node-x").Obj(),
			},
			want: &preScoreState{
				Constraints: []topologySpreadConstraint{
					{
						MaxSkew:     1,
						TopologyKey: "zone",
						Selector:    mustConvertLabelSelectorAsSelector(t, st.MakeLabelSelector().Exists("foo").Obj()),
					},
					{
						MaxSkew:     1,
						TopologyKey: "node",
						Selector:    mustConvertLabelSelectorAsSelector(t, st.MakeLabelSelector().Exists("bar").Obj()),
					},
				},
				NodeNameSet: sets.NewString("node-a", "node-b"),
				TopologyPairToPodCounts: map[topologyPair]*int64{
					{key: "zone", value: "zone1"}:  pointer.Int64Ptr(0),
					{key: "node", value: "node-a"}: pointer.Int64Ptr(0),
					{key: "node", value: "node-b"}: pointer.Int64Ptr(0),
				},
			},
		},
		{
			name: "defaults constraints and a replica set",
			pod:  st.MakePod().Name("p").Label("foo", "tar").Label("baz", "sup").Obj(),
			defaultConstraints: []v1.TopologySpreadConstraint{
				{MaxSkew: 1, TopologyKey: "node", WhenUnsatisfiable: v1.ScheduleAnyway},
				{MaxSkew: 2, TopologyKey: "rack", WhenUnsatisfiable: v1.DoNotSchedule},
				{MaxSkew: 2, TopologyKey: "planet", WhenUnsatisfiable: v1.ScheduleAnyway},
			},
			nodes: []*v1.Node{
				st.MakeNode().Name("node-a").Label("rack", "rack1").Label("node", "node-a").Label("planet", "mars").Obj(),
			},
			objs: []runtime.Object{
				&appsv1.ReplicaSet{Spec: appsv1.ReplicaSetSpec{Selector: st.MakeLabelSelector().Exists("foo").Obj()}},
			},
			want: &preScoreState{
				Constraints: []topologySpreadConstraint{
					{
						MaxSkew:     1,
						TopologyKey: "node",
						Selector:    mustConvertLabelSelectorAsSelector(t, st.MakeLabelSelector().Exists("foo").Obj()),
					},
					{
						MaxSkew:     2,
						TopologyKey: "planet",
						Selector:    mustConvertLabelSelectorAsSelector(t, st.MakeLabelSelector().Exists("foo").Obj()),
					},
				},
				NodeNameSet: sets.NewString("node-a"),
				TopologyPairToPodCounts: map[topologyPair]*int64{
					{key: "node", value: "node-a"}: pointer.Int64Ptr(0),
					{key: "planet", value: "mars"}: pointer.Int64Ptr(0),
				},
			},
		},
		{
			name: "defaults constraints and a replica set that doesn't match",
			pod:  st.MakePod().Name("p").Label("foo", "bar").Label("baz", "sup").Obj(),
			defaultConstraints: []v1.TopologySpreadConstraint{
				{MaxSkew: 2, TopologyKey: "planet", WhenUnsatisfiable: v1.ScheduleAnyway},
			},
			nodes: []*v1.Node{
				st.MakeNode().Name("node-a").Label("planet", "mars").Obj(),
			},
			objs: []runtime.Object{
				&appsv1.ReplicaSet{Spec: appsv1.ReplicaSetSpec{Selector: st.MakeLabelSelector().Exists("tar").Obj()}},
			},
			want: &preScoreState{
				TopologyPairToPodCounts: make(map[topologyPair]*int64),
			},
		},
		{
			name: "defaults constraints and a replica set, but pod has constraints",
			pod: st.MakePod().Name("p").Label("foo", "bar").Label("baz", "sup").
				SpreadConstraint(1, "zone", v1.DoNotSchedule, st.MakeLabelSelector().Label("foo", "bar").Obj()).
				SpreadConstraint(2, "planet", v1.ScheduleAnyway, st.MakeLabelSelector().Label("baz", "sup").Obj()).Obj(),
			defaultConstraints: []v1.TopologySpreadConstraint{
				{MaxSkew: 2, TopologyKey: "galaxy", WhenUnsatisfiable: v1.ScheduleAnyway},
			},
			nodes: []*v1.Node{
				st.MakeNode().Name("node-a").Label("planet", "mars").Label("galaxy", "andromeda").Obj(),
			},
			objs: []runtime.Object{
				&appsv1.ReplicaSet{Spec: appsv1.ReplicaSetSpec{Selector: st.MakeLabelSelector().Exists("foo").Obj()}},
			},
			want: &preScoreState{
				Constraints: []topologySpreadConstraint{
					{
						MaxSkew:     2,
						TopologyKey: "planet",
						Selector:    mustConvertLabelSelectorAsSelector(t, st.MakeLabelSelector().Label("baz", "sup").Obj()),
					},
				},
				NodeNameSet: sets.NewString("node-a"),
				TopologyPairToPodCounts: map[topologyPair]*int64{
					{"planet", "mars"}: pointer.Int64Ptr(0),
				},
			},
		},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			ctx := context.Background()
			informerFactory := informers.NewSharedInformerFactory(fake.NewSimpleClientset(tt.objs...), 0)
			pl := PodTopologySpread{
				sharedLister: cache.NewSnapshot(nil, tt.nodes),
				Args: Args{
					DefaultConstraints: tt.defaultConstraints,
				},
			}
			pl.setListers(informerFactory)
			informerFactory.Start(ctx.Done())
			informerFactory.WaitForCacheSync(ctx.Done())
			cs := framework.NewCycleState()
			if s := pl.PreScore(context.Background(), cs, tt.pod, tt.nodes); !s.IsSuccess() {
				t.Fatal(s.AsError())
			}

			got, err := getPreScoreState(cs)
			if err != nil {
				t.Fatal(err)
			}
			if diff := cmp.Diff(tt.want, got, cmpOpts...); diff != "" {
				t.Errorf("PodTopologySpread#PreScore() returned (-want, +got):\n%s", diff)
			}
		})
	}
}

func TestPodTopologySpreadScore(t *testing.T) {
	tests := []struct {
		name         string
		pod          *v1.Pod
		existingPods []*v1.Pod
		nodes        []*v1.Node
		failedNodes  []*v1.Node // nodes + failedNodes = all nodes
		want         framework.NodeScoreList
	}{
		// Explanation on the Legend:
		// a) X/Y means there are X matching pods on node1 and Y on node2, both nodes are candidates
		//   (i.e. they have passed all predicates)
		// b) X/~Y~ means there are X matching pods on node1 and Y on node2, but node Y is NOT a candidate
		// c) X/?Y? means there are X matching pods on node1 and Y on node2, both nodes are candidates
		//    but node2 either i) doesn't have all required topologyKeys present, or ii) doesn't match
		//    incoming pod's nodeSelector/nodeAffinity
		{
			// if there is only one candidate node, it should be scored to 10
			name: "one constraint on node, no existing pods",
			pod: st.MakePod().Name("p").Label("foo", "").
				SpreadConstraint(1, "node", v1.ScheduleAnyway, st.MakeLabelSelector().Exists("foo").Obj()).
				Obj(),
			nodes: []*v1.Node{
				st.MakeNode().Name("node-a").Label("node", "node-a").Obj(),
				st.MakeNode().Name("node-b").Label("node", "node-b").Obj(),
			},
			want: []framework.NodeScore{
				{Name: "node-a", Score: 100},
				{Name: "node-b", Score: 100},
			},
		},
		{
			// if there is only one candidate node, it should be scored to 10
			name: "one constraint on node, only one node is candidate",
			pod: st.MakePod().Name("p").Label("foo", "").
				SpreadConstraint(1, "node", v1.ScheduleAnyway, st.MakeLabelSelector().Exists("foo").Obj()).
				Obj(),
			existingPods: []*v1.Pod{
				st.MakePod().Name("p-a1").Node("node-a").Label("foo", "").Obj(),
				st.MakePod().Name("p-a2").Node("node-a").Label("foo", "").Obj(),
				st.MakePod().Name("p-b1").Node("node-b").Label("foo", "").Obj(),
			},
			nodes: []*v1.Node{
				st.MakeNode().Name("node-a").Label("node", "node-a").Obj(),
			},
			failedNodes: []*v1.Node{
				st.MakeNode().Name("node-b").Label("node", "node-b").Obj(),
			},
			want: []framework.NodeScore{
				{Name: "node-a", Score: 100},
			},
		},
		{
			name: "one constraint on node, all nodes have the same number of matching pods",
			pod: st.MakePod().Name("p").Label("foo", "").
				SpreadConstraint(1, "node", v1.ScheduleAnyway, st.MakeLabelSelector().Exists("foo").Obj()).
				Obj(),
			existingPods: []*v1.Pod{
				st.MakePod().Name("p-a1").Node("node-a").Label("foo", "").Obj(),
				st.MakePod().Name("p-b1").Node("node-b").Label("foo", "").Obj(),
			},
			nodes: []*v1.Node{
				st.MakeNode().Name("node-a").Label("node", "node-a").Obj(),
				st.MakeNode().Name("node-b").Label("node", "node-b").Obj(),
			},
			want: []framework.NodeScore{
				{Name: "node-a", Score: 100},
				{Name: "node-b", Score: 100},
			},
		},
		{
			// matching pods spread as 2/1/0/3, total = 6
			// after reversing, it's 4/5/6/3
			// so scores = 400/6, 500/6, 600/6, 300/6
			name: "one constraint on node, all 4 nodes are candidates",
			pod: st.MakePod().Name("p").Label("foo", "").
				SpreadConstraint(1, "node", v1.ScheduleAnyway, st.MakeLabelSelector().Exists("foo").Obj()).
				Obj(),
			existingPods: []*v1.Pod{
				st.MakePod().Name("p-a1").Node("node-a").Label("foo", "").Obj(),
				st.MakePod().Name("p-a2").Node("node-a").Label("foo", "").Obj(),
				st.MakePod().Name("p-b1").Node("node-b").Label("foo", "").Obj(),
				st.MakePod().Name("p-d1").Node("node-d").Label("foo", "").Obj(),
				st.MakePod().Name("p-d2").Node("node-d").Label("foo", "").Obj(),
				st.MakePod().Name("p-d3").Node("node-d").Label("foo", "").Obj(),
			},
			nodes: []*v1.Node{
				st.MakeNode().Name("node-a").Label("node", "node-a").Obj(),
				st.MakeNode().Name("node-b").Label("node", "node-b").Obj(),
				st.MakeNode().Name("node-c").Label("node", "node-c").Obj(),
				st.MakeNode().Name("node-d").Label("node", "node-d").Obj(),
			},
			failedNodes: []*v1.Node{},
			want: []framework.NodeScore{
				{Name: "node-a", Score: 66},
				{Name: "node-b", Score: 83},
				{Name: "node-c", Score: 100},
				{Name: "node-d", Score: 50},
			},
		},
		{
			// matching pods spread as 4/2/1/~3~, total = 4+2+1 = 7 (as node4 is not a candidate)
			// after reversing, it's 3/5/6
			// so scores = 300/6, 500/6, 600/6
			name: "one constraint on node, 3 out of 4 nodes are candidates",
			pod: st.MakePod().Name("p").Label("foo", "").
				SpreadConstraint(1, "node", v1.ScheduleAnyway, st.MakeLabelSelector().Exists("foo").Obj()).
				Obj(),
			existingPods: []*v1.Pod{
				st.MakePod().Name("p-a1").Node("node-a").Label("foo", "").Obj(),
				st.MakePod().Name("p-a2").Node("node-a").Label("foo", "").Obj(),
				st.MakePod().Name("p-a3").Node("node-a").Label("foo", "").Obj(),
				st.MakePod().Name("p-a4").Node("node-a").Label("foo", "").Obj(),
				st.MakePod().Name("p-b1").Node("node-b").Label("foo", "").Obj(),
				st.MakePod().Name("p-b2").Node("node-b").Label("foo", "").Obj(),
				st.MakePod().Name("p-x1").Node("node-x").Label("foo", "").Obj(),
				st.MakePod().Name("p-y1").Node("node-y").Label("foo", "").Obj(),
				st.MakePod().Name("p-y2").Node("node-y").Label("foo", "").Obj(),
				st.MakePod().Name("p-y3").Node("node-y").Label("foo", "").Obj(),
			},
			nodes: []*v1.Node{
				st.MakeNode().Name("node-a").Label("node", "node-a").Obj(),
				st.MakeNode().Name("node-b").Label("node", "node-b").Obj(),
				st.MakeNode().Name("node-x").Label("node", "node-x").Obj(),
			},
			failedNodes: []*v1.Node{
				st.MakeNode().Name("node-y").Label("node", "node-y").Obj(),
			},
			want: []framework.NodeScore{
				{Name: "node-a", Score: 50},
				{Name: "node-b", Score: 83},
				{Name: "node-x", Score: 100},
			},
		},
		{
			// matching pods spread as 4/?2?/1/~3~, total = 4+?+1 = 5 (as node2 is problematic)
			// after reversing, it's 1/?/4
			// so scores = 100/4, 0, 400/4
			name: "one constraint on node, 3 out of 4 nodes are candidates",
			pod: st.MakePod().Name("p").Label("foo", "").
				SpreadConstraint(1, "node", v1.ScheduleAnyway, st.MakeLabelSelector().Exists("foo").Obj()).
				Obj(),
			existingPods: []*v1.Pod{
				st.MakePod().Name("p-a1").Node("node-a").Label("foo", "").Obj(),
				st.MakePod().Name("p-a2").Node("node-a").Label("foo", "").Obj(),
				st.MakePod().Name("p-a3").Node("node-a").Label("foo", "").Obj(),
				st.MakePod().Name("p-a4").Node("node-a").Label("foo", "").Obj(),
				st.MakePod().Name("p-b1").Node("node-b").Label("foo", "").Obj(),
				st.MakePod().Name("p-b2").Node("node-b").Label("foo", "").Obj(),
				st.MakePod().Name("p-x1").Node("node-x").Label("foo", "").Obj(),
				st.MakePod().Name("p-y1").Node("node-y").Label("foo", "").Obj(),
				st.MakePod().Name("p-y2").Node("node-y").Label("foo", "").Obj(),
				st.MakePod().Name("p-y3").Node("node-y").Label("foo", "").Obj(),
			},
			nodes: []*v1.Node{
				st.MakeNode().Name("node-a").Label("node", "node-a").Obj(),
				st.MakeNode().Name("node-b").Label("n", "node-b").Obj(), // label `n` doesn't match topologyKey
				st.MakeNode().Name("node-x").Label("node", "node-x").Obj(),
			},
			failedNodes: []*v1.Node{
				st.MakeNode().Name("node-y").Label("node", "node-y").Obj(),
			},
			want: []framework.NodeScore{
				{Name: "node-a", Score: 25},
				{Name: "node-b", Score: 0},
				{Name: "node-x", Score: 100},
			},
		},
		{
			// matching pods spread as 4/2/1/~3~, total = 6+6+4 = 16 (as topologyKey is zone instead of node)
			// after reversing, it's 10/10/12
			// so scores = 1000/12, 1000/12, 1200/12
			name: "one constraint on zone, 3 out of 4 nodes are candidates",
			pod: st.MakePod().Name("p").Label("foo", "").
				SpreadConstraint(1, "zone", v1.ScheduleAnyway, st.MakeLabelSelector().Exists("foo").Obj()).
				Obj(),
			existingPods: []*v1.Pod{
				st.MakePod().Name("p-a1").Node("node-a").Label("foo", "").Obj(),
				st.MakePod().Name("p-a2").Node("node-a").Label("foo", "").Obj(),
				st.MakePod().Name("p-a3").Node("node-a").Label("foo", "").Obj(),
				st.MakePod().Name("p-a4").Node("node-a").Label("foo", "").Obj(),
				st.MakePod().Name("p-b1").Node("node-b").Label("foo", "").Obj(),
				st.MakePod().Name("p-b2").Node("node-b").Label("foo", "").Obj(),
				st.MakePod().Name("p-x1").Node("node-x").Label("foo", "").Obj(),
				st.MakePod().Name("p-y1").Node("node-y").Label("foo", "").Obj(),
				st.MakePod().Name("p-y2").Node("node-y").Label("foo", "").Obj(),
				st.MakePod().Name("p-y3").Node("node-y").Label("foo", "").Obj(),
			},
			nodes: []*v1.Node{
				st.MakeNode().Name("node-a").Label("zone", "zone1").Label("node", "node-a").Obj(),
				st.MakeNode().Name("node-b").Label("zone", "zone1").Label("node", "node-b").Obj(),
				st.MakeNode().Name("node-x").Label("zone", "zone2").Label("node", "node-x").Obj(),
			},
			failedNodes: []*v1.Node{
				st.MakeNode().Name("node-y").Label("zone", "zone2").Label("node", "node-y").Obj(),
			},
			want: []framework.NodeScore{
				{Name: "node-a", Score: 83},
				{Name: "node-b", Score: 83},
				{Name: "node-x", Score: 100},
			},
		},
		{
			// matching pods spread as 2/~1~/2/~4~, total = 2+3 + 2+6 = 13 (zone and node should be both summed up)
			// after reversing, it's 8/5
			// so scores = 800/8, 500/8
			name: "two Constraints on zone and node, 2 out of 4 nodes are candidates",
			pod: st.MakePod().Name("p").Label("foo", "").
				SpreadConstraint(1, "zone", v1.ScheduleAnyway, st.MakeLabelSelector().Exists("foo").Obj()).
				SpreadConstraint(1, "node", v1.ScheduleAnyway, st.MakeLabelSelector().Exists("foo").Obj()).
				Obj(),
			existingPods: []*v1.Pod{
				st.MakePod().Name("p-a1").Node("node-a").Label("foo", "").Obj(),
				st.MakePod().Name("p-a2").Node("node-a").Label("foo", "").Obj(),
				st.MakePod().Name("p-b1").Node("node-b").Label("foo", "").Obj(),
				st.MakePod().Name("p-x1").Node("node-x").Label("foo", "").Obj(),
				st.MakePod().Name("p-x2").Node("node-x").Label("foo", "").Obj(),
				st.MakePod().Name("p-y1").Node("node-y").Label("foo", "").Obj(),
				st.MakePod().Name("p-y2").Node("node-y").Label("foo", "").Obj(),
				st.MakePod().Name("p-y3").Node("node-y").Label("foo", "").Obj(),
				st.MakePod().Name("p-y4").Node("node-y").Label("foo", "").Obj(),
			},
			nodes: []*v1.Node{
				st.MakeNode().Name("node-a").Label("zone", "zone1").Label("node", "node-a").Obj(),
				st.MakeNode().Name("node-x").Label("zone", "zone2").Label("node", "node-x").Obj(),
			},
			failedNodes: []*v1.Node{
				st.MakeNode().Name("node-b").Label("zone", "zone1").Label("node", "node-b").Obj(),
				st.MakeNode().Name("node-y").Label("zone", "zone2").Label("node", "node-y").Obj(),
			},
			want: []framework.NodeScore{
				{Name: "node-a", Score: 100},
				{Name: "node-x", Score: 62},
			},
		},
		{
			// If Constraints hold different labelSelectors, it's a little complex.
			// +----------------------+------------------------+
			// |         zone1        |          zone2         |
			// +----------------------+------------------------+
			// | node-a |    node-b   | node-x |     node-y    |
			// +--------+-------------+--------+---------------+
			// | P{foo} | P{foo, bar} |        | P{foo} P{bar} |
			// +--------+-------------+--------+---------------+
			// For the first constraint (zone): the matching pods spread as 2/2/1/1
			// For the second constraint (node): the matching pods spread as 0/1/0/1
			// sum them up gets: 2/3/1/2, and total number is 8.
			// after reversing, it's 6/5/7/6
			// so scores = 600/7, 500/7, 700/7, 600/7
			name: "two Constraints on zone and node, with different labelSelectors",
			pod: st.MakePod().Name("p").Label("foo", "").Label("bar", "").
				SpreadConstraint(1, "zone", v1.ScheduleAnyway, st.MakeLabelSelector().Exists("foo").Obj()).
				SpreadConstraint(1, "node", v1.ScheduleAnyway, st.MakeLabelSelector().Exists("bar").Obj()).
				Obj(),
			existingPods: []*v1.Pod{
				st.MakePod().Name("p-a1").Node("node-a").Label("foo", "").Obj(),
				st.MakePod().Name("p-b1").Node("node-b").Label("foo", "").Label("bar", "").Obj(),
				st.MakePod().Name("p-y1").Node("node-y").Label("foo", "").Obj(),
				st.MakePod().Name("p-y2").Node("node-y").Label("bar", "").Obj(),
			},
			nodes: []*v1.Node{
				st.MakeNode().Name("node-a").Label("zone", "zone1").Label("node", "node-a").Obj(),
				st.MakeNode().Name("node-b").Label("zone", "zone1").Label("node", "node-b").Obj(),
				st.MakeNode().Name("node-x").Label("zone", "zone2").Label("node", "node-x").Obj(),
				st.MakeNode().Name("node-y").Label("zone", "zone2").Label("node", "node-y").Obj(),
			},
			failedNodes: []*v1.Node{},
			want: []framework.NodeScore{
				{Name: "node-a", Score: 85},
				{Name: "node-b", Score: 71},
				{Name: "node-x", Score: 100},
				{Name: "node-y", Score: 85},
			},
		},
		{
			// For the first constraint (zone): the matching pods spread as 0/0/2/2
			// For the second constraint (node): the matching pods spread as 0/1/0/1
			// sum them up gets: 0/1/2/3, and total number is 6.
			// after reversing, it's 6/5/4/3.
			// so scores = 600/6, 500/6, 400/6, 300/6
			name: "two Constraints on zone and node, with different labelSelectors, some nodes have 0 pods",
			pod: st.MakePod().Name("p").Label("foo", "").Label("bar", "").
				SpreadConstraint(1, "zone", v1.ScheduleAnyway, st.MakeLabelSelector().Exists("foo").Obj()).
				SpreadConstraint(1, "node", v1.ScheduleAnyway, st.MakeLabelSelector().Exists("bar").Obj()).
				Obj(),
			existingPods: []*v1.Pod{
				st.MakePod().Name("p-b1").Node("node-b").Label("bar", "").Obj(),
				st.MakePod().Name("p-x1").Node("node-x").Label("foo", "").Obj(),
				st.MakePod().Name("p-y1").Node("node-y").Label("foo", "").Label("bar", "").Obj(),
			},
			nodes: []*v1.Node{
				st.MakeNode().Name("node-a").Label("zone", "zone1").Label("node", "node-a").Obj(),
				st.MakeNode().Name("node-b").Label("zone", "zone1").Label("node", "node-b").Obj(),
				st.MakeNode().Name("node-x").Label("zone", "zone2").Label("node", "node-x").Obj(),
				st.MakeNode().Name("node-y").Label("zone", "zone2").Label("node", "node-y").Obj(),
			},
			failedNodes: []*v1.Node{},
			want: []framework.NodeScore{
				{Name: "node-a", Score: 100},
				{Name: "node-b", Score: 83},
				{Name: "node-x", Score: 66},
				{Name: "node-y", Score: 50},
			},
		},
		{
			// For the first constraint (zone): the matching pods spread as 2/2/1/~1~
			// For the second constraint (node): the matching pods spread as 0/1/0/~1~
			// sum them up gets: 2/3/1, and total number is 6.
			// after reversing, it's 4/3/5
			// so scores = 400/5, 300/5, 500/5
			name: "two Constraints on zone and node, with different labelSelectors, 3 out of 4 nodes are candidates",
			pod: st.MakePod().Name("p").Label("foo", "").Label("bar", "").
				SpreadConstraint(1, "zone", v1.ScheduleAnyway, st.MakeLabelSelector().Exists("foo").Obj()).
				SpreadConstraint(1, "node", v1.ScheduleAnyway, st.MakeLabelSelector().Exists("bar").Obj()).
				Obj(),
			existingPods: []*v1.Pod{
				st.MakePod().Name("p-a1").Node("node-a").Label("foo", "").Obj(),
				st.MakePod().Name("p-b1").Node("node-b").Label("foo", "").Label("bar", "").Obj(),
				st.MakePod().Name("p-y1").Node("node-y").Label("foo", "").Obj(),
				st.MakePod().Name("p-y2").Node("node-y").Label("bar", "").Obj(),
			},
			nodes: []*v1.Node{
				st.MakeNode().Name("node-a").Label("zone", "zone1").Label("node", "node-a").Obj(),
				st.MakeNode().Name("node-b").Label("zone", "zone1").Label("node", "node-b").Obj(),
				st.MakeNode().Name("node-x").Label("zone", "zone2").Label("node", "node-x").Obj(),
			},
			failedNodes: []*v1.Node{
				st.MakeNode().Name("node-y").Label("zone", "zone2").Label("node", "node-y").Obj(),
			},
			want: []framework.NodeScore{
				{Name: "node-a", Score: 80},
				{Name: "node-b", Score: 60},
				{Name: "node-x", Score: 100},
			},
		},
		{
			name: "existing pods in a different namespace do not count",
			pod: st.MakePod().Name("p").Label("foo", "").
				SpreadConstraint(1, "node", v1.ScheduleAnyway, st.MakeLabelSelector().Exists("foo").Obj()).
				Obj(),
			existingPods: []*v1.Pod{
				st.MakePod().Name("p-a1").Namespace("ns1").Node("node-a").Label("foo", "").Obj(),
				st.MakePod().Name("p-a2").Node("node-a").Label("foo", "").Obj(),
				st.MakePod().Name("p-b1").Node("node-b").Label("foo", "").Obj(),
				st.MakePod().Name("p-b2").Node("node-b").Label("foo", "").Obj(),
			},
			nodes: []*v1.Node{
				st.MakeNode().Name("node-a").Label("node", "node-a").Obj(),
				st.MakeNode().Name("node-b").Label("node", "node-b").Obj(),
			},
			want: []framework.NodeScore{
				{Name: "node-a", Score: 100},
				{Name: "node-b", Score: 50},
			},
		},
		{
			name: "terminating Pods should be excluded",
			pod: st.MakePod().Name("p").Label("foo", "").SpreadConstraint(
				1, "node", v1.ScheduleAnyway, st.MakeLabelSelector().Exists("foo").Obj(),
			).Obj(),
			nodes: []*v1.Node{
				st.MakeNode().Name("node-a").Label("node", "node-a").Obj(),
				st.MakeNode().Name("node-b").Label("node", "node-b").Obj(),
			},
			existingPods: []*v1.Pod{
				st.MakePod().Name("p-a").Node("node-a").Label("foo", "").Terminating().Obj(),
				st.MakePod().Name("p-b").Node("node-b").Label("foo", "").Obj(),
			},
			want: []framework.NodeScore{
				{Name: "node-a", Score: 100},
				{Name: "node-b", Score: 0},
			},
		},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			allNodes := append([]*v1.Node{}, tt.nodes...)
			allNodes = append(allNodes, tt.failedNodes...)
			state := framework.NewCycleState()
			snapshot := cache.NewSnapshot(tt.existingPods, allNodes)
			p := &PodTopologySpread{sharedLister: snapshot}

			status := p.PreScore(context.Background(), state, tt.pod, tt.nodes)
			if !status.IsSuccess() {
				t.Errorf("unexpected error: %v", status)
			}

			var gotList framework.NodeScoreList
			for _, n := range tt.nodes {
				nodeName := n.Name
				score, status := p.Score(context.Background(), state, tt.pod, nodeName)
				if !status.IsSuccess() {
					t.Errorf("unexpected error: %v", status)
				}
				gotList = append(gotList, framework.NodeScore{Name: nodeName, Score: score})
			}

			status = p.NormalizeScore(context.Background(), state, tt.pod, gotList)
			if !status.IsSuccess() {
				t.Errorf("unexpected error: %v", status)
			}
			if diff := cmp.Diff(tt.want, gotList, cmpOpts...); diff != "" {
				t.Errorf("unexpected scores (-want,+got):\n%s", diff)
			}
		})
	}
}

func BenchmarkTestPodTopologySpreadScore(b *testing.B) {
	tests := []struct {
		name             string
		pod              *v1.Pod
		existingPodsNum  int
		allNodesNum      int
		filteredNodesNum int
	}{
		{
			name: "1000nodes/single-constraint-zone",
			pod: st.MakePod().Name("p").Label("foo", "").
				SpreadConstraint(1, v1.LabelZoneFailureDomain, v1.ScheduleAnyway, st.MakeLabelSelector().Exists("foo").Obj()).
				Obj(),
			existingPodsNum:  10000,
			allNodesNum:      1000,
			filteredNodesNum: 500,
		},
		{
			name: "1000nodes/single-constraint-node",
			pod: st.MakePod().Name("p").Label("foo", "").
				SpreadConstraint(1, v1.LabelHostname, v1.ScheduleAnyway, st.MakeLabelSelector().Exists("foo").Obj()).
				Obj(),
			existingPodsNum:  10000,
			allNodesNum:      1000,
			filteredNodesNum: 500,
		},
		{
			name: "1000nodes/two-Constraints-zone-node",
			pod: st.MakePod().Name("p").Label("foo", "").Label("bar", "").
				SpreadConstraint(1, v1.LabelZoneFailureDomain, v1.ScheduleAnyway, st.MakeLabelSelector().Exists("foo").Obj()).
				SpreadConstraint(1, v1.LabelHostname, v1.ScheduleAnyway, st.MakeLabelSelector().Exists("bar").Obj()).
				Obj(),
			existingPodsNum:  10000,
			allNodesNum:      1000,
			filteredNodesNum: 500,
		},
	}
	for _, tt := range tests {
		b.Run(tt.name, func(b *testing.B) {
			existingPods, allNodes, filteredNodes := st.MakeNodesAndPodsForEvenPodsSpread(tt.pod.Labels, tt.existingPodsNum, tt.allNodesNum, tt.filteredNodesNum)
			state := framework.NewCycleState()
			snapshot := cache.NewSnapshot(existingPods, allNodes)
			p := &PodTopologySpread{sharedLister: snapshot}

			status := p.PreScore(context.Background(), state, tt.pod, filteredNodes)
			if !status.IsSuccess() {
				b.Fatalf("unexpected error: %v", status)
			}
			b.ResetTimer()

			for i := 0; i < b.N; i++ {
				var gotList framework.NodeScoreList
				for _, n := range filteredNodes {
					nodeName := n.Name
					score, status := p.Score(context.Background(), state, tt.pod, nodeName)
					if !status.IsSuccess() {
						b.Fatalf("unexpected error: %v", status)
					}
					gotList = append(gotList, framework.NodeScore{Name: nodeName, Score: score})
				}

				status = p.NormalizeScore(context.Background(), state, tt.pod, gotList)
				if !status.IsSuccess() {
					b.Fatal(status)
				}
			}
		})
	}
}

// The following test allows to compare PodTopologySpread.Score with
// DefaultPodTopologySpread.Score by using a similar rule.
// See pkg/scheduler/framework/plugins/defaultpodtopologyspread/default_pod_topology_spread_perf_test.go
// for the equivalent test.

var (
	tests = []struct {
		name            string
		existingPodsNum int
		allNodesNum     int
	}{
		{
			name:            "100nodes",
			existingPodsNum: 1000,
			allNodesNum:     100,
		},
		{
			name:            "1000nodes",
			existingPodsNum: 10000,
			allNodesNum:     1000,
		},
	}
)

func BenchmarkTestDefaultEvenPodsSpreadPriority(b *testing.B) {
	for _, tt := range tests {
		b.Run(tt.name, func(b *testing.B) {
			pod := st.MakePod().Name("p").Label("foo", "").Obj()
			existingPods, allNodes, filteredNodes := st.MakeNodesAndPodsForEvenPodsSpread(pod.Labels, tt.existingPodsNum, tt.allNodesNum, tt.allNodesNum)
			state := framework.NewCycleState()
			snapshot := cache.NewSnapshot(existingPods, allNodes)
			p := &PodTopologySpread{
				sharedLister: snapshot,
				Args: Args{
					DefaultConstraints: []v1.TopologySpreadConstraint{
						{MaxSkew: 1, TopologyKey: v1.LabelHostname, WhenUnsatisfiable: v1.ScheduleAnyway},
						{MaxSkew: 1, TopologyKey: v1.LabelZoneFailureDomain, WhenUnsatisfiable: v1.ScheduleAnyway},
					},
				},
			}
			client := fake.NewSimpleClientset(
				&v1.Service{Spec: v1.ServiceSpec{Selector: map[string]string{"foo": ""}}},
			)
			ctx := context.Background()
			informerFactory := informers.NewSharedInformerFactory(client, 0)
			p.setListers(informerFactory)
			informerFactory.Start(ctx.Done())
			informerFactory.WaitForCacheSync(ctx.Done())

			b.ResetTimer()

			for i := 0; i < b.N; i++ {
				var gotList framework.NodeScoreList
				status := p.PreScore(ctx, state, pod, filteredNodes)
				if !status.IsSuccess() {
					b.Fatalf("unexpected error: %v", status)
				}
				for _, n := range filteredNodes {
					score, status := p.Score(context.Background(), state, pod, n.Name)
					if !status.IsSuccess() {
						b.Fatalf("unexpected error: %v", status)
					}
					gotList = append(gotList, framework.NodeScore{Name: n.Name, Score: score})
				}
				status = p.NormalizeScore(context.Background(), state, pod, gotList)
				if !status.IsSuccess() {
					b.Fatal(status)
				}
			}
		})
	}
}
