/*
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 options

import (
	"github.com/spf13/pflag"

	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	kubectrlmgrconfig "k8s.io/kubernetes/pkg/controller/apis/config"
)

// HPAControllerOptions holds the HPAController options.
type HPAControllerOptions struct {
	HorizontalPodAutoscalerUseRESTClients               bool
	HorizontalPodAutoscalerTolerance                    float64
	HorizontalPodAutoscalerDownscaleStabilizationWindow metav1.Duration
	HorizontalPodAutoscalerDownscaleForbiddenWindow     metav1.Duration
	HorizontalPodAutoscalerUpscaleForbiddenWindow       metav1.Duration
	HorizontalPodAutoscalerSyncPeriod                   metav1.Duration
	HorizontalPodAutoscalerCPUInitializationPeriod      metav1.Duration
	HorizontalPodAutoscalerInitialReadinessDelay        metav1.Duration
}

// AddFlags adds flags related to HPAController for controller manager to the specified FlagSet.
func (o *HPAControllerOptions) AddFlags(fs *pflag.FlagSet) {
	if o == nil {
		return
	}

	fs.DurationVar(&o.HorizontalPodAutoscalerSyncPeriod.Duration, "horizontal-pod-autoscaler-sync-period", o.HorizontalPodAutoscalerSyncPeriod.Duration, "The period for syncing the number of pods in horizontal pod autoscaler.")
	fs.DurationVar(&o.HorizontalPodAutoscalerUpscaleForbiddenWindow.Duration, "horizontal-pod-autoscaler-upscale-delay", o.HorizontalPodAutoscalerUpscaleForbiddenWindow.Duration, "The period since last upscale, before another upscale can be performed in horizontal pod autoscaler.")
	fs.MarkDeprecated("horizontal-pod-autoscaler-upscale-delay", "This flag is currently no-op and will be deleted.")
	fs.DurationVar(&o.HorizontalPodAutoscalerDownscaleStabilizationWindow.Duration, "horizontal-pod-autoscaler-downscale-stabilization", o.HorizontalPodAutoscalerDownscaleStabilizationWindow.Duration, "The period for which autoscaler will look backwards and not scale down below any recommendation it made during that period.")
	fs.DurationVar(&o.HorizontalPodAutoscalerDownscaleForbiddenWindow.Duration, "horizontal-pod-autoscaler-downscale-delay", o.HorizontalPodAutoscalerDownscaleForbiddenWindow.Duration, "The period since last downscale, before another downscale can be performed in horizontal pod autoscaler.")
	fs.MarkDeprecated("horizontal-pod-autoscaler-downscale-delay", "This flag is currently no-op and will be deleted.")
	fs.Float64Var(&o.HorizontalPodAutoscalerTolerance, "horizontal-pod-autoscaler-tolerance", o.HorizontalPodAutoscalerTolerance, "The minimum change (from 1.0) in the desired-to-actual metrics ratio for the horizontal pod autoscaler to consider scaling.")
	fs.BoolVar(&o.HorizontalPodAutoscalerUseRESTClients, "horizontal-pod-autoscaler-use-rest-clients", o.HorizontalPodAutoscalerUseRESTClients, "If set to true, causes the horizontal pod autoscaler controller to use REST clients through the kube-aggregator, instead of using the legacy metrics client through the API server proxy.  This is required for custom metrics support in the horizontal pod autoscaler.")
	fs.DurationVar(&o.HorizontalPodAutoscalerCPUInitializationPeriod.Duration, "horizontal-pod-autoscaler-cpu-initialization-period", o.HorizontalPodAutoscalerCPUInitializationPeriod.Duration, "The period after pod start when CPU samples might be skipped.")
	fs.MarkDeprecated("horizontal-pod-autoscaler-use-rest-clients", "Heapster is no longer supported as a source for Horizontal Pod Autoscaler metrics.")
	fs.DurationVar(&o.HorizontalPodAutoscalerInitialReadinessDelay.Duration, "horizontal-pod-autoscaler-initial-readiness-delay", o.HorizontalPodAutoscalerInitialReadinessDelay.Duration, "The period after pod start during which readiness changes will be treated as initial readiness.")
}

// ApplyTo fills up HPAController config with options.
func (o *HPAControllerOptions) ApplyTo(cfg *kubectrlmgrconfig.HPAControllerConfiguration) error {
	if o == nil {
		return nil
	}

	cfg.HorizontalPodAutoscalerSyncPeriod = o.HorizontalPodAutoscalerSyncPeriod
	cfg.HorizontalPodAutoscalerDownscaleStabilizationWindow = o.HorizontalPodAutoscalerDownscaleStabilizationWindow
	cfg.HorizontalPodAutoscalerTolerance = o.HorizontalPodAutoscalerTolerance
	cfg.HorizontalPodAutoscalerUseRESTClients = o.HorizontalPodAutoscalerUseRESTClients
	cfg.HorizontalPodAutoscalerCPUInitializationPeriod = o.HorizontalPodAutoscalerCPUInitializationPeriod
	cfg.HorizontalPodAutoscalerInitialReadinessDelay = o.HorizontalPodAutoscalerInitialReadinessDelay

	return nil
}

// Validate checks validation of HPAControllerOptions.
func (o *HPAControllerOptions) Validate() []error {
	if o == nil {
		return nil
	}

	errs := []error{}
	return errs
}