/*
Copyright 2021 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 cpumanager

import (
	"testing"

	utilfeature "k8s.io/apiserver/pkg/util/feature"
	"k8s.io/component-base/featuregate"
	featuregatetesting "k8s.io/component-base/featuregate/testing"
	pkgfeatures "k8s.io/kubernetes/pkg/features"
	"k8s.io/kubernetes/pkg/kubelet/cm/cpumanager/topology"
	"k8s.io/kubernetes/pkg/kubelet/cm/topologymanager"
)

type optionAvailTest struct {
	option            string
	featureGate       featuregate.Feature
	featureGateEnable bool
	expectedAvailable bool
}

func TestPolicyDefaultsAvailable(t *testing.T) {
	testCases := []optionAvailTest{
		{
			option:            "this-option-does-not-exist",
			expectedAvailable: false,
		},
		{
			option:            FullPCPUsOnlyOption,
			expectedAvailable: true,
		},
	}
	for _, testCase := range testCases {
		t.Run(testCase.option, func(t *testing.T) {
			err := CheckPolicyOptionAvailable(testCase.option)
			isEnabled := (err == nil)
			if isEnabled != testCase.expectedAvailable {
				t.Errorf("option %q available got=%v expected=%v", testCase.option, isEnabled, testCase.expectedAvailable)
			}
		})
	}
}

func TestPolicyOptionsAvailable(t *testing.T) {
	testCases := []optionAvailTest{
		{
			option:            "this-option-does-not-exist",
			featureGate:       pkgfeatures.CPUManagerPolicyBetaOptions,
			featureGateEnable: false,
			expectedAvailable: false,
		},
		{
			option:            "this-option-does-not-exist",
			featureGate:       pkgfeatures.CPUManagerPolicyBetaOptions,
			featureGateEnable: true,
			expectedAvailable: false,
		},
		{
			option:            FullPCPUsOnlyOption,
			featureGate:       pkgfeatures.CPUManagerPolicyBetaOptions,
			featureGateEnable: true,
			expectedAvailable: true,
		},
		{
			option:            FullPCPUsOnlyOption,
			featureGate:       pkgfeatures.CPUManagerPolicyBetaOptions,
			featureGateEnable: false,
			expectedAvailable: false,
		},
		{
			option:            AlignBySocketOption,
			featureGate:       pkgfeatures.CPUManagerPolicyAlphaOptions,
			featureGateEnable: true,
			expectedAvailable: true,
		},
		{
			option:            AlignBySocketOption,
			featureGate:       pkgfeatures.CPUManagerPolicyBetaOptions,
			featureGateEnable: true,
			expectedAvailable: false,
		},
		{
			option:            DistributeCPUsAcrossNUMAOption,
			featureGate:       pkgfeatures.CPUManagerPolicyAlphaOptions,
			featureGateEnable: true,
			expectedAvailable: true,
		},
		{
			option:            DistributeCPUsAcrossNUMAOption,
			featureGate:       pkgfeatures.CPUManagerPolicyBetaOptions,
			featureGateEnable: true,
			expectedAvailable: false,
		},
		{
			option:            DistributeCPUsAcrossCoresOption,
			featureGate:       pkgfeatures.CPUManagerPolicyAlphaOptions,
			featureGateEnable: true,
			expectedAvailable: true,
		},
		{
			option:            DistributeCPUsAcrossCoresOption,
			featureGate:       pkgfeatures.CPUManagerPolicyBetaOptions,
			featureGateEnable: true,
			expectedAvailable: false,
		},
		{
			option:            StrictCPUReservationOption,
			featureGate:       pkgfeatures.CPUManagerPolicyAlphaOptions,
			featureGateEnable: true,
			expectedAvailable: true,
		},
		{
			option:            StrictCPUReservationOption,
			featureGate:       pkgfeatures.CPUManagerPolicyBetaOptions,
			featureGateEnable: true,
			expectedAvailable: false,
		},
	}
	for _, testCase := range testCases {
		t.Run(testCase.option, func(t *testing.T) {
			featuregatetesting.SetFeatureGateDuringTest(t, utilfeature.DefaultFeatureGate, testCase.featureGate, testCase.featureGateEnable)
			err := CheckPolicyOptionAvailable(testCase.option)
			isEnabled := (err == nil)
			if isEnabled != testCase.expectedAvailable {
				t.Errorf("option %q available got=%v expected=%v", testCase.option, isEnabled, testCase.expectedAvailable)
			}
		})
	}
}

func TestValidateStaticPolicyOptions(t *testing.T) {
	testCases := []struct {
		description   string
		policyOption  map[string]string
		topology      *topology.CPUTopology
		topoMgrPolicy string
		expectedErr   bool
	}{
		{
			description:   "Align by socket not enabled",
			policyOption:  map[string]string{FullPCPUsOnlyOption: "true"},
			topology:      topoDualSocketMultiNumaPerSocketHT,
			topoMgrPolicy: topologymanager.PolicySingleNumaNode,
			expectedErr:   false,
		},
		{
			description:   "Align by socket enabled with topology manager single numa node",
			policyOption:  map[string]string{AlignBySocketOption: "true"},
			topology:      topoDualSocketMultiNumaPerSocketHT,
			topoMgrPolicy: topologymanager.PolicySingleNumaNode,
			expectedErr:   true,
		},
		{
			description:   "Align by socket enabled with num_sockets > num_numa",
			policyOption:  map[string]string{AlignBySocketOption: "true"},
			topology:      fakeTopoMultiSocketDualSocketPerNumaHT,
			topoMgrPolicy: topologymanager.PolicyNone,
			expectedErr:   true,
		},
		{
			description:   "Align by socket enabled: with topology manager None policy",
			policyOption:  map[string]string{AlignBySocketOption: "true"},
			topology:      topoDualSocketMultiNumaPerSocketHT,
			topoMgrPolicy: topologymanager.PolicyNone,
			expectedErr:   false,
		},
		{
			description:   "Align by socket enabled: with topology manager best-effort policy",
			policyOption:  map[string]string{AlignBySocketOption: "true"},
			topology:      topoDualSocketMultiNumaPerSocketHT,
			topoMgrPolicy: topologymanager.PolicyBestEffort,
			expectedErr:   false,
		},
		{
			description:   "Align by socket enabled: with topology manager restricted policy",
			policyOption:  map[string]string{AlignBySocketOption: "true"},
			topology:      topoDualSocketMultiNumaPerSocketHT,
			topoMgrPolicy: topologymanager.PolicyRestricted,
			expectedErr:   false,
		},
	}
	for _, testCase := range testCases {
		t.Run(testCase.description, func(t *testing.T) {
			topoMgrPolicy := topologymanager.NewNonePolicy()
			if testCase.topoMgrPolicy == topologymanager.PolicySingleNumaNode {
				topoMgrPolicy = topologymanager.NewSingleNumaNodePolicy(&topologymanager.NUMAInfo{}, topologymanager.PolicyOptions{})
			}
			topoMgrStore := topologymanager.NewFakeManagerWithPolicy(topoMgrPolicy)

			featuregatetesting.SetFeatureGateDuringTest(t, utilfeature.DefaultFeatureGate, pkgfeatures.CPUManagerPolicyAlphaOptions, true)
			policyOpt, _ := NewStaticPolicyOptions(testCase.policyOption)
			err := ValidateStaticPolicyOptions(policyOpt, testCase.topology, topoMgrStore)
			gotError := (err != nil)
			if gotError != testCase.expectedErr {
				t.Errorf("testCase %q failed, got %v expected %v", testCase.description, gotError, testCase.expectedErr)
			}
		})
	}
}

func TestPolicyOptionsCompatibility(t *testing.T) {
	// take feature gate into the consideration
	testCases := []struct {
		description   string
		featureGate   featuregate.Feature
		policyOptions map[string]string
		expectedErr   bool
	}{
		{
			description: "FullPhysicalCPUsOnly set to true only",
			featureGate: pkgfeatures.CPUManagerPolicyBetaOptions,
			policyOptions: map[string]string{
				FullPCPUsOnlyOption: "true",
			},
			expectedErr: false,
		},
		{
			description: "DistributeCPUsAcrossCores set to true only",
			featureGate: pkgfeatures.CPUManagerPolicyAlphaOptions,
			policyOptions: map[string]string{
				DistributeCPUsAcrossCoresOption: "true",
			},
			expectedErr: false,
		},
		{
			description: "FullPhysicalCPUsOnly and DistributeCPUsAcrossCores options can not coexist",
			featureGate: pkgfeatures.CPUManagerPolicyAlphaOptions,
			policyOptions: map[string]string{
				FullPCPUsOnlyOption:             "true",
				DistributeCPUsAcrossCoresOption: "true",
			},
			expectedErr: true,
		},
	}
	for _, testCase := range testCases {
		t.Run(testCase.description, func(t *testing.T) {
			featuregatetesting.SetFeatureGateDuringTest(t, utilfeature.DefaultFeatureGate, testCase.featureGate, true)
			_, err := NewStaticPolicyOptions(testCase.policyOptions)
			gotError := err != nil
			if gotError != testCase.expectedErr {
				t.Errorf("testCase %q failed, got %v expected %v", testCase.description, gotError, testCase.expectedErr)
			}
		})
	}
}
