/*
Copyright 2016 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 (
	"fmt"
	"time"

	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	utilerrors "k8s.io/apimachinery/pkg/util/errors"
	utilfeature "k8s.io/apiserver/pkg/util/feature"
	cloudcontrollerconfig "k8s.io/kubernetes/cmd/cloud-controller-manager/app/config"
	cmoptions "k8s.io/kubernetes/cmd/controller-manager/app/options"
	"k8s.io/kubernetes/pkg/master/ports"

	// add the kubernetes feature gates
	_ "k8s.io/kubernetes/pkg/features"

	"github.com/spf13/pflag"
)

// CloudControllerManagerOptions is the main context object for the controller manager.
type CloudControllerManagerOptions struct {
	Generic *cmoptions.GenericControllerManagerOptions

	// NodeStatusUpdateFrequency is the frequency at which the controller updates nodes' status
	NodeStatusUpdateFrequency metav1.Duration
}

// NewCloudControllerManagerOptions creates a new ExternalCMServer with a default config.
func NewCloudControllerManagerOptions() *CloudControllerManagerOptions {
	componentConfig := cmoptions.NewDefaultControllerManagerComponentConfig(ports.InsecureCloudControllerManagerPort)

	s := CloudControllerManagerOptions{
		// The common/default are kept in 'cmd/kube-controller-manager/app/options/util.go'.
		// Please make common changes there and put anything cloud specific here.
		Generic:                   cmoptions.NewGenericControllerManagerOptions(componentConfig),
		NodeStatusUpdateFrequency: metav1.Duration{Duration: 5 * time.Minute},
	}

	s.Generic.SecureServing.ServerCert.CertDirectory = "/var/run/kubernetes"
	s.Generic.SecureServing.ServerCert.PairName = "cloud-controller-manager"

	return &s
}

// AddFlags adds flags for a specific ExternalCMServer to the specified FlagSet
func (o *CloudControllerManagerOptions) AddFlags(fs *pflag.FlagSet) {
	o.Generic.AddFlags(fs)

	fs.DurationVar(&o.NodeStatusUpdateFrequency.Duration, "node-status-update-frequency", o.NodeStatusUpdateFrequency.Duration, "Specifies how often the controller updates nodes' status.")

	utilfeature.DefaultFeatureGate.AddFlag(fs)
}

// ApplyTo fills up cloud controller manager config with options.
func (o *CloudControllerManagerOptions) ApplyTo(c *cloudcontrollerconfig.Config) error {
	if err := o.Generic.ApplyTo(&c.Generic, "cloud-controller-manager"); err != nil {
		return err
	}

	c.Extra.NodeStatusUpdateFrequency = o.NodeStatusUpdateFrequency.Duration

	return nil
}

// Validate is used to validate config before launching the cloud controller manager
func (o *CloudControllerManagerOptions) Validate() error {
	errors := []error{}
	errors = append(errors, o.Generic.Validate()...)

	if len(o.Generic.CloudProvider.Name) == 0 {
		errors = append(errors, fmt.Errorf("--cloud-provider cannot be empty"))
	}

	return utilerrors.NewAggregate(errors)
}

// Config return a cloud controller manager config objective
func (o CloudControllerManagerOptions) Config() (*cloudcontrollerconfig.Config, error) {
	if err := o.Validate(); err != nil {
		return nil, err
	}

	c := &cloudcontrollerconfig.Config{}
	if err := o.ApplyTo(c); err != nil {
		return nil, err
	}

	return c, nil
}