/*
Copyright 2023 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 applicationfailover

import (
	"reflect"
	"testing"

	"github.com/stretchr/testify/assert"
	"k8s.io/apimachinery/pkg/types"
	"k8s.io/apimachinery/pkg/util/sets"

	workv1alpha2 "github.com/karmada-io/karmada/pkg/apis/work/v1alpha2"
)

func TestTimeStampProcess(t *testing.T) {
	key := types.NamespacedName{
		Namespace: "default",
		Name:      "test",
	}
	cluster := "cluster-1"

	m := newWorkloadUnhealthyMap()
	m.setTimeStamp(key, cluster)
	res := m.hasWorkloadBeenUnhealthy(key, cluster)
	assert.Equal(t, true, res)

	time := m.getTimeStamp(key, cluster)
	assert.NotEmpty(t, time)

	m.delete(key)
	res = m.hasWorkloadBeenUnhealthy(key, cluster)
	assert.Equal(t, false, res)
}

func TestWorkloadUnhealthyMap_deleteIrrelevantClusters(t *testing.T) {
	cluster1 := "cluster-1"
	cluster2 := "cluster-2"
	cluster3 := "cluster-3"
	t.Run("normal case", func(t *testing.T) {
		key := types.NamespacedName{
			Namespace: "default",
			Name:      "test",
		}

		m := newWorkloadUnhealthyMap()

		m.setTimeStamp(key, cluster1)
		m.setTimeStamp(key, cluster2)
		m.setTimeStamp(key, cluster3)

		allClusters := sets.New[string](cluster2, cluster3)
		healthyClusters := []string{cluster3}

		m.deleteIrrelevantClusters(key, allClusters, healthyClusters)
		res1 := m.hasWorkloadBeenUnhealthy(key, cluster1)
		assert.Equal(t, false, res1)
		res2 := m.hasWorkloadBeenUnhealthy(key, cluster2)
		assert.Equal(t, true, res2)
		res3 := m.hasWorkloadBeenUnhealthy(key, cluster3)
		assert.Equal(t, false, res3)
	})

	t.Run("unhealthyClusters is nil", func(t *testing.T) {
		key := types.NamespacedName{
			Namespace: "default",
			Name:      "test",
		}

		m := newWorkloadUnhealthyMap()

		allClusters := sets.New[string](cluster2, cluster3)
		healthyClusters := []string{cluster3}

		m.deleteIrrelevantClusters(key, allClusters, healthyClusters)
		res := m.hasWorkloadBeenUnhealthy(key, cluster2)
		assert.Equal(t, false, res)
	})
}

func TestDistinguishUnhealthyClustersWithOthers(t *testing.T) {
	tests := []struct {
		name                  string
		aggregatedStatusItems []workv1alpha2.AggregatedStatusItem
		resourceBindingSpec   workv1alpha2.ResourceBindingSpec
		expectedClusters      []string
		expectedOthers        []string
	}{
		{
			name: "all applications are healthy",
			aggregatedStatusItems: []workv1alpha2.AggregatedStatusItem{
				{
					ClusterName: "member1",
					Health:      workv1alpha2.ResourceHealthy,
				},
				{
					ClusterName: "member2",
					Health:      workv1alpha2.ResourceHealthy,
				},
			},
			resourceBindingSpec: workv1alpha2.ResourceBindingSpec{},
			expectedClusters:    nil,
			expectedOthers:      []string{"member1", "member2"},
		},
		{
			name: "all applications are unknown",
			aggregatedStatusItems: []workv1alpha2.AggregatedStatusItem{
				{
					ClusterName: "member1",
					Health:      workv1alpha2.ResourceUnknown,
				},
				{
					ClusterName: "member2",
					Health:      workv1alpha2.ResourceUnknown,
				},
			},
			resourceBindingSpec: workv1alpha2.ResourceBindingSpec{},
			expectedClusters:    nil,
			expectedOthers:      []string{"member1", "member2"},
		},
		{
			name: "one application is unhealthy and not in gracefulEvictionTasks",
			aggregatedStatusItems: []workv1alpha2.AggregatedStatusItem{
				{
					ClusterName: "member1",
					Health:      workv1alpha2.ResourceHealthy,
				},
				{
					ClusterName: "member2",
					Health:      workv1alpha2.ResourceUnhealthy,
				},
			},
			resourceBindingSpec: workv1alpha2.ResourceBindingSpec{},
			expectedClusters:    []string{"member2"},
			expectedOthers:      []string{"member1"},
		},
		{
			name: "one application is unhealthy and in gracefulEvictionTasks",
			aggregatedStatusItems: []workv1alpha2.AggregatedStatusItem{
				{
					ClusterName: "member1",
					Health:      workv1alpha2.ResourceHealthy,
				},
				{
					ClusterName: "member2",
					Health:      workv1alpha2.ResourceUnhealthy,
				},
			},
			resourceBindingSpec: workv1alpha2.ResourceBindingSpec{
				GracefulEvictionTasks: []workv1alpha2.GracefulEvictionTask{
					{
						FromCluster: "member2",
					},
				},
			},
			expectedClusters: nil,
			expectedOthers:   []string{"member1"},
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			if got, gotOthers := distinguishUnhealthyClustersWithOthers(tt.aggregatedStatusItems, tt.resourceBindingSpec); !reflect.DeepEqual(got, tt.expectedClusters) || !reflect.DeepEqual(gotOthers, tt.expectedOthers) {
				t.Errorf("distinguishUnhealthyClustersWithOthers() = (%v, %v), want (%v, %v)", got, gotOthers, tt.expectedClusters, tt.expectedOthers)
			}
		})
	}
}