/*
Copyright 2016 The Rook Authors. All rights reserved.

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 operator to manage Kubernetes storage.
package operator

import (
	"fmt"
	"os"
	"os/signal"
	"syscall"
	"time"

	"github.com/coreos/pkg/capnslog"
	opkit "github.com/rook/operator-kit"
	"github.com/rook/rook/pkg/clusterd"
	"github.com/rook/rook/pkg/daemon/agent/flexvolume/attachment"
	"github.com/rook/rook/pkg/operator/agent"
	"github.com/rook/rook/pkg/operator/cluster"
	"github.com/rook/rook/pkg/operator/file"
	"github.com/rook/rook/pkg/operator/k8sutil"
	"github.com/rook/rook/pkg/operator/object"
	"github.com/rook/rook/pkg/operator/pool"
	"github.com/rook/rook/pkg/operator/provisioner"
	"github.com/rook/rook/pkg/operator/provisioner/controller"
	"k8s.io/api/core/v1"
)

const (
	initRetryDelay = 10 * time.Second
)

// volume provisioner constant
const (
	provisionerName = "rook.io/block"
)

var logger = capnslog.NewPackageLogger("github.com/rook/rook", "operator")

// Operator type for managing storage
type Operator struct {
	context   *clusterd.Context
	resources []opkit.CustomResource
	rookImage string
	// The custom resource that is global to the kubernetes cluster.
	// The cluster is global because you create multiple clusters in k8s
	clusterController *cluster.ClusterController
	volumeProvisioner controller.Provisioner
}

// New creates an operator instance
func New(context *clusterd.Context, volumeAttachmentWrapper attachment.Attachment, rookImage string) *Operator {
	clusterController := cluster.NewClusterController(context, rookImage, volumeAttachmentWrapper)
	volumeProvisioner := provisioner.New(context)

	schemes := []opkit.CustomResource{cluster.ClusterResource, pool.PoolResource, object.ObjectStoreResource,
		file.FilesystemResource, attachment.VolumeAttachmentResource}
	return &Operator{
		context:           context,
		clusterController: clusterController,
		resources:         schemes,
		volumeProvisioner: volumeProvisioner,
		rookImage:         rookImage,
	}
}

// Run the operator instance
func (o *Operator) Run() error {

	namespace := os.Getenv(k8sutil.PodNamespaceEnvVar)
	if namespace == "" {
		return fmt.Errorf("Rook operator namespace is not provided. Expose it via downward API in the rook operator manifest file using environment variable %s", k8sutil.PodNamespaceEnvVar)
	}

	for {
		err := o.initResources()
		if err == nil {
			break
		}
		logger.Errorf("failed to init resources. %+v. retrying...", err)
		<-time.After(initRetryDelay)
	}

	rookAgent := agent.New(o.context.Clientset)

	if err := rookAgent.Start(namespace, o.rookImage); err != nil {
		return fmt.Errorf("Error starting agent daemonset: %v", err)
	}

	signalChan := make(chan os.Signal, 1)
	stopChan := make(chan struct{})
	signal.Notify(signalChan, syscall.SIGINT, syscall.SIGTERM)

	// Run volume provisioner
	// The controller needs to know what the server version is because out-of-tree
	// provisioners aren't officially supported until 1.5
	serverVersion, err := o.context.Clientset.Discovery().ServerVersion()
	if err != nil {
		return fmt.Errorf("Error getting server version: %v", err)
	}
	pc := controller.NewProvisionController(
		o.context.Clientset,
		provisionerName,
		o.volumeProvisioner,
		serverVersion.GitVersion,
	)
	go pc.Run(stopChan)
	logger.Infof("rook-provisioner started")

	// watch for changes to the rook clusters
	o.clusterController.StartWatch(v1.NamespaceAll, stopChan)

	for {
		select {
		case <-signalChan:
			logger.Infof("shutdown signal received, exiting...")
			close(stopChan)
			return nil
		}
	}
}

func (o *Operator) initResources() error {
	kitCtx := opkit.Context{
		Clientset:             o.context.Clientset,
		APIExtensionClientset: o.context.APIExtensionClientset,
		Interval:              500 * time.Millisecond,
		Timeout:               60 * time.Second,
	}

	// Create and wait for CRD resources
	err := opkit.CreateCustomResources(kitCtx, o.resources)
	if err != nil {
		return fmt.Errorf("failed to create custom resource. %+v", err)
	}
	return nil
}