/*
Copyright 2018 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 test

import (
	"fmt"
	"reflect"
	"testing"

	"k8s.io/autoscaler/cluster-autoscaler/debuggingsnapshot"

	"k8s.io/apimachinery/pkg/api/resource"
	"k8s.io/autoscaler/cluster-autoscaler/cloudprovider"
	testcloudprovider "k8s.io/autoscaler/cluster-autoscaler/cloudprovider/test"
	"k8s.io/autoscaler/cluster-autoscaler/clusterstate/utils"
	"k8s.io/autoscaler/cluster-autoscaler/config"
	"k8s.io/autoscaler/cluster-autoscaler/context"
	"k8s.io/autoscaler/cluster-autoscaler/core/filteroutschedulable"
	"k8s.io/autoscaler/cluster-autoscaler/core/scaledown/deletiontracker"
	"k8s.io/autoscaler/cluster-autoscaler/estimator"
	"k8s.io/autoscaler/cluster-autoscaler/expander/random"
	"k8s.io/autoscaler/cluster-autoscaler/metrics"
	"k8s.io/autoscaler/cluster-autoscaler/processors"
	"k8s.io/autoscaler/cluster-autoscaler/processors/actionablecluster"
	processor_callbacks "k8s.io/autoscaler/cluster-autoscaler/processors/callbacks"
	"k8s.io/autoscaler/cluster-autoscaler/processors/customresources"
	"k8s.io/autoscaler/cluster-autoscaler/processors/nodegroupconfig"
	"k8s.io/autoscaler/cluster-autoscaler/processors/nodegroups"
	"k8s.io/autoscaler/cluster-autoscaler/processors/nodegroupset"
	"k8s.io/autoscaler/cluster-autoscaler/processors/nodeinfos"
	"k8s.io/autoscaler/cluster-autoscaler/processors/nodeinfosprovider"
	"k8s.io/autoscaler/cluster-autoscaler/processors/nodes"
	"k8s.io/autoscaler/cluster-autoscaler/processors/status"
	"k8s.io/autoscaler/cluster-autoscaler/simulator"
	"k8s.io/autoscaler/cluster-autoscaler/utils/errors"
	kube_util "k8s.io/autoscaler/cluster-autoscaler/utils/kubernetes"
	"k8s.io/autoscaler/cluster-autoscaler/utils/labels"

	"github.com/stretchr/testify/assert"

	apiv1 "k8s.io/api/core/v1"
	"k8s.io/autoscaler/cluster-autoscaler/clusterstate"
	"k8s.io/autoscaler/cluster-autoscaler/utils/backoff"
	kube_client "k8s.io/client-go/kubernetes"
	kube_record "k8s.io/client-go/tools/record"
	schedulerframework "k8s.io/kubernetes/pkg/scheduler/framework"
)

// NodeConfig is a node config used in tests
type NodeConfig struct {
	Name   string
	Cpu    int64
	Memory int64
	Gpu    int64
	Ready  bool
	Group  string
}

// PodConfig is a pod config used in tests
type PodConfig struct {
	Name         string
	Cpu          int64
	Memory       int64
	Gpu          int64
	Node         string
	ToleratesGpu bool
}

// GroupSizeChange represents a change in group size
type GroupSizeChange struct {
	GroupName  string
	SizeChange int
}

// ScaleTestConfig represents a config of a scale test
type ScaleTestConfig struct {
	Nodes                   []NodeConfig
	Pods                    []PodConfig
	ExtraPods               []PodConfig
	Options                 config.AutoscalingOptions
	NodeDeletionTracker     *deletiontracker.NodeDeletionTracker
	ExpansionOptionToChoose GroupSizeChange // this will be selected by assertingStrategy.BestOption

	ExpectedScaleDowns     []string
	ExpectedScaleDownCount int
}

// ScaleTestResults contains results of a scale test
type ScaleTestResults struct {
	ExpansionOptions []GroupSizeChange
	FinalOption      GroupSizeChange
	NoScaleUpReason  string
	FinalScaleDowns  []string
	Events           []string
	ScaleUpStatus    ScaleUpStatusInfo
}

// ScaleUpStatusInfo is a simplified form of a ScaleUpStatus, to avoid mocking actual NodeGroup and Pod objects in test config.
type ScaleUpStatusInfo struct {
	Result                  status.ScaleUpResult
	PodsTriggeredScaleUp    []string
	PodsRemainUnschedulable []string
	PodsAwaitEvaluation     []string
}

// WasSuccessful returns true iff scale up was successful
func (s *ScaleUpStatusInfo) WasSuccessful() bool {
	return s.Result == status.ScaleUpSuccessful
}

// ExtractPodNames extract pod names from a list of pods
func ExtractPodNames(pods []*apiv1.Pod) []string {
	podNames := []string{}
	for _, pod := range pods {
		podNames = append(podNames, pod.Name)
	}
	return podNames
}

// NewTestProcessors returns a set of simple processors for use in tests.
func NewTestProcessors() *processors.AutoscalingProcessors {
	return &processors.AutoscalingProcessors{
		PodListProcessor:       filteroutschedulable.NewFilterOutSchedulablePodListProcessor(),
		NodeGroupListProcessor: &nodegroups.NoOpNodeGroupListProcessor{},
		NodeGroupSetProcessor:  nodegroupset.NewDefaultNodeGroupSetProcessor([]string{}),
		ScaleDownSetProcessor:  nodes.NewPostFilteringScaleDownNodeProcessor(),
		// TODO(bskiba): change scale up test so that this can be a NoOpProcessor
		ScaleUpStatusProcessor:     &status.EventingScaleUpStatusProcessor{},
		ScaleDownStatusProcessor:   &status.NoOpScaleDownStatusProcessor{},
		AutoscalingStatusProcessor: &status.NoOpAutoscalingStatusProcessor{},
		NodeGroupManager:           nodegroups.NewDefaultNodeGroupManager(),
		NodeInfoProcessor:          nodeinfos.NewDefaultNodeInfoProcessor(),
		TemplateNodeInfoProvider:   nodeinfosprovider.NewDefaultTemplateNodeInfoProvider(nil),
		NodeGroupConfigProcessor:   nodegroupconfig.NewDefaultNodeGroupConfigProcessor(),
		CustomResourcesProcessor:   customresources.NewDefaultCustomResourcesProcessor(),
		ActionableClusterProcessor: actionablecluster.NewDefaultActionableClusterProcessor(),
	}
}

// NewScaleTestAutoscalingContext creates a new test autoscaling context for scaling tests.
func NewScaleTestAutoscalingContext(
	options config.AutoscalingOptions, fakeClient kube_client.Interface,
	listers kube_util.ListerRegistry, provider cloudprovider.CloudProvider,
	processorCallbacks processor_callbacks.ProcessorCallbacks, debuggingSnapshotter debuggingsnapshot.DebuggingSnapshotter) (context.AutoscalingContext, error) {
	// Not enough buffer space causes the test to hang without printing any logs.
	// This is not useful.
	fakeRecorder := kube_record.NewFakeRecorder(100)
	fakeLogRecorder, err := utils.NewStatusMapRecorder(fakeClient, "kube-system", fakeRecorder, false, "my-cool-configmap")
	if err != nil {
		return context.AutoscalingContext{}, err
	}
	// Ignoring error here is safe - if a test doesn't specify valid estimatorName,
	// it either doesn't need one, or should fail when it turns out to be nil.
	estimatorBuilder, _ := estimator.NewEstimatorBuilder(options.EstimatorName)
	predicateChecker, err := simulator.NewTestPredicateChecker()
	if err != nil {
		return context.AutoscalingContext{}, err
	}
	if debuggingSnapshotter == nil {
		debuggingSnapshotter = debuggingsnapshot.NewDebuggingSnapshotter(false)
	}
	clusterSnapshot := simulator.NewBasicClusterSnapshot()
	return context.AutoscalingContext{
		AutoscalingOptions: options,
		AutoscalingKubeClients: context.AutoscalingKubeClients{
			ClientSet:      fakeClient,
			Recorder:       fakeRecorder,
			LogRecorder:    fakeLogRecorder,
			ListerRegistry: listers,
		},
		CloudProvider:        provider,
		PredicateChecker:     predicateChecker,
		ClusterSnapshot:      clusterSnapshot,
		ExpanderStrategy:     random.NewStrategy(),
		EstimatorBuilder:     estimatorBuilder,
		ProcessorCallbacks:   processorCallbacks,
		DebuggingSnapshotter: debuggingSnapshotter,
	}, nil
}

// MockAutoprovisioningNodeGroupManager is a mock node group manager to be used in tests
type MockAutoprovisioningNodeGroupManager struct {
	T           *testing.T
	ExtraGroups int
}

// CreateNodeGroup creates a new node group
func (p *MockAutoprovisioningNodeGroupManager) CreateNodeGroup(context *context.AutoscalingContext, nodeGroup cloudprovider.NodeGroup) (nodegroups.CreateNodeGroupResult, errors.AutoscalerError) {
	newNodeGroup, err := nodeGroup.Create()
	assert.NoError(p.T, err)
	metrics.RegisterNodeGroupCreation()
	extraGroups := []cloudprovider.NodeGroup{}
	testGroup, ok := nodeGroup.(*testcloudprovider.TestNodeGroup)
	if !ok {
		return nodegroups.CreateNodeGroupResult{}, errors.ToAutoscalerError(errors.InternalError, fmt.Errorf("expected test node group, found %v", reflect.TypeOf(nodeGroup)))
	}
	testCloudProvider, ok := context.CloudProvider.(*testcloudprovider.TestCloudProvider)
	if !ok {
		return nodegroups.CreateNodeGroupResult{}, errors.ToAutoscalerError(errors.InternalError, fmt.Errorf("expected test CloudProvider, found %v", reflect.TypeOf(context.CloudProvider)))
	}
	for i := 0; i < p.ExtraGroups; i++ {
		extraNodeGroup, err := testCloudProvider.NewNodeGroupWithId(
			testGroup.MachineType(),
			testGroup.Labels(),
			map[string]string{},
			[]apiv1.Taint{},
			map[string]resource.Quantity{},
			fmt.Sprintf("%d", i+1),
		)
		assert.NoError(p.T, err)
		extraGroup, err := extraNodeGroup.Create()
		assert.NoError(p.T, err)
		metrics.RegisterNodeGroupCreation()
		extraGroups = append(extraGroups, extraGroup)
	}
	result := nodegroups.CreateNodeGroupResult{
		MainCreatedNodeGroup:   newNodeGroup,
		ExtraCreatedNodeGroups: extraGroups,
	}
	return result, nil
}

// RemoveUnneededNodeGroups removes uneeded node groups
func (p *MockAutoprovisioningNodeGroupManager) RemoveUnneededNodeGroups(context *context.AutoscalingContext) (removedNodeGroups []cloudprovider.NodeGroup, err error) {
	if !context.AutoscalingOptions.NodeAutoprovisioningEnabled {
		return nil, nil
	}
	removedNodeGroups = make([]cloudprovider.NodeGroup, 0)
	nodeGroups := context.CloudProvider.NodeGroups()
	for _, nodeGroup := range nodeGroups {
		if !nodeGroup.Autoprovisioned() {
			continue
		}
		targetSize, err := nodeGroup.TargetSize()
		assert.NoError(p.T, err)
		if targetSize > 0 {
			continue
		}
		nodes, err := nodeGroup.Nodes()
		assert.NoError(p.T, err)
		if len(nodes) > 0 {
			continue
		}
		err = nodeGroup.Delete()
		assert.NoError(p.T, err)
		removedNodeGroups = append(removedNodeGroups, nodeGroup)
	}
	return removedNodeGroups, nil
}

// CleanUp doesn't do anything; it's here to satisfy the interface
func (p *MockAutoprovisioningNodeGroupManager) CleanUp() {
}

// MockAutoprovisioningNodeGroupListProcessor is a fake node group list processor to be used in tests
type MockAutoprovisioningNodeGroupListProcessor struct {
	T *testing.T
}

// Process extends the list of node groups
func (p *MockAutoprovisioningNodeGroupListProcessor) Process(context *context.AutoscalingContext, nodeGroups []cloudprovider.NodeGroup, nodeInfos map[string]*schedulerframework.NodeInfo,
	unschedulablePods []*apiv1.Pod) ([]cloudprovider.NodeGroup, map[string]*schedulerframework.NodeInfo, error) {

	machines, err := context.CloudProvider.GetAvailableMachineTypes()
	assert.NoError(p.T, err)

	bestLabels := labels.BestLabelSet(unschedulablePods)
	for _, machineType := range machines {
		nodeGroup, err := context.CloudProvider.NewNodeGroup(machineType, bestLabels, map[string]string{}, []apiv1.Taint{}, map[string]resource.Quantity{})
		assert.NoError(p.T, err)
		nodeInfo, err := nodeGroup.TemplateNodeInfo()
		assert.NoError(p.T, err)
		nodeInfos[nodeGroup.Id()] = nodeInfo
		nodeGroups = append(nodeGroups, nodeGroup)
	}
	return nodeGroups, nodeInfos, nil
}

// CleanUp doesn't do anything; it's here to satisfy the interface
func (p *MockAutoprovisioningNodeGroupListProcessor) CleanUp() {
}

// NewBackoff creates a new backoff object
func NewBackoff() backoff.Backoff {
	return backoff.NewIdBasedExponentialBackoff(clusterstate.InitialNodeGroupBackoffDuration, clusterstate.MaxNodeGroupBackoffDuration, clusterstate.NodeGroupBackoffResetTimeout)
}