/*
Copyright 2021 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 csi

import (
	"context"
	"os"

	cephv1 "github.com/rook/rook/pkg/apis/ceph.rook.io/v1"
	"sigs.k8s.io/controller-runtime/pkg/client"
	"sigs.k8s.io/controller-runtime/pkg/controller"
	"sigs.k8s.io/controller-runtime/pkg/handler"
	"sigs.k8s.io/controller-runtime/pkg/manager"
	"sigs.k8s.io/controller-runtime/pkg/reconcile"
	"sigs.k8s.io/controller-runtime/pkg/source"

	"github.com/pkg/errors"
	"github.com/rook/rook/pkg/clusterd"
	opcontroller "github.com/rook/rook/pkg/operator/ceph/controller"
	"github.com/rook/rook/pkg/operator/ceph/csi/peermap"
	"github.com/rook/rook/pkg/operator/k8sutil"
	v1 "k8s.io/api/core/v1"
	kerrors "k8s.io/apimachinery/pkg/api/errors"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/types"
)

const (
	controllerName = "rook-ceph-operator-csi-controller"
)

// ReconcileCSI reconciles a ceph-csi driver
type ReconcileCSI struct {
	client           client.Client
	context          *clusterd.Context
	opManagerContext context.Context
	opConfig         opcontroller.OperatorConfig
}

// Add creates a new Ceph CSI Controller and adds it to the Manager. The Manager will set fields on the Controller
// and Start it when the Manager is Started.
func Add(mgr manager.Manager, context *clusterd.Context, opManagerContext context.Context, opConfig opcontroller.OperatorConfig) error {
	return add(mgr, newReconciler(mgr, context, opManagerContext, opConfig))
}

// newReconciler returns a new reconcile.Reconciler
func newReconciler(mgr manager.Manager, context *clusterd.Context, opManagerContext context.Context, opConfig opcontroller.OperatorConfig) reconcile.Reconciler {
	return &ReconcileCSI{
		client:           mgr.GetClient(),
		context:          context,
		opConfig:         opConfig,
		opManagerContext: opManagerContext,
	}
}

func add(mgr manager.Manager, r reconcile.Reconciler) error {
	// Create a new controller
	c, err := controller.New(controllerName, mgr, controller.Options{Reconciler: r})
	if err != nil {
		return err
	}
	logger.Infof("%s successfully started", controllerName)

	// Watch for ConfigMap (operator config)
	err = c.Watch(&source.Kind{
		Type: &v1.ConfigMap{TypeMeta: metav1.TypeMeta{Kind: "ConfigMap", APIVersion: v1.SchemeGroupVersion.String()}}}, &handler.EnqueueRequestForObject{}, predicateController())
	if err != nil {
		return err
	}

	// Watch for CephCluster
	err = c.Watch(&source.Kind{
		Type: &cephv1.CephCluster{TypeMeta: metav1.TypeMeta{Kind: "CephCluster", APIVersion: v1.SchemeGroupVersion.String()}}}, &handler.EnqueueRequestForObject{}, predicateController())
	if err != nil {
		return err
	}

	return nil
}

// Reconcile reads that state of the operator config map and makes changes based on the state read
// The Controller will requeue the Request to be processed again if the returned error is non-nil or
// Result.Requeue is true, otherwise upon completion it will remove the work from the queue.
func (r *ReconcileCSI) Reconcile(context context.Context, request reconcile.Request) (reconcile.Result, error) {
	// workaround because the rook logging mechanism is not compatible with the controller-runtime logging interface
	reconcileResponse, err := r.reconcile(request)
	if err != nil {
		logger.Errorf("failed to reconcile %v", err)
	}

	return reconcileResponse, err
}

func (r *ReconcileCSI) reconcile(request reconcile.Request) (reconcile.Result, error) {
	// See if there is a CephCluster
	cephClusters := &cephv1.CephClusterList{}
	err := r.client.List(r.opManagerContext, cephClusters, &client.ListOptions{})
	if err != nil {
		if kerrors.IsNotFound(err) {
			logger.Debug("no ceph cluster found not deploying ceph csi driver")
			return reconcile.Result{}, nil
		}
		// Error reading the object - requeue the request.
		return opcontroller.ImmediateRetryResult, errors.Wrap(err, "failed to list ceph clusters")
	}

	// // Do not nothing if no ceph cluster is present
	if len(cephClusters.Items) == 0 {
		logger.Debug("no ceph cluster found not deploying ceph csi driver")
		return reconcile.Result{}, nil
	} else {
		for _, cluster := range cephClusters.Items {
			if !cluster.DeletionTimestamp.IsZero() {
				logger.Debug("ceph cluster is being deleting, no need to reconcile the csi driver")
				return reconcile.Result{}, nil
			}

			if !cluster.Spec.External.Enable && cluster.Spec.CleanupPolicy.HasDataDirCleanPolicy() {
				logger.Debug("ceph cluster has cleanup policy, the cluster will soon go away, no need to reconcile the csi driver")
				return reconcile.Result{}, nil
			}
		}
	}

	// Fetch the operator's configmap. We force the NamespaceName to the operator since the request
	// could be a CephCluster. If so the NamespaceName will be the one from the cluster and thus the
	// CM won't be found
	opNamespaceName := types.NamespacedName{Name: opcontroller.OperatorSettingConfigMapName, Namespace: r.opConfig.OperatorNamespace}
	opConfig := &v1.ConfigMap{}
	err = r.client.Get(r.opManagerContext, opNamespaceName, opConfig)
	if err != nil {
		if kerrors.IsNotFound(err) {
			logger.Debug("operator's configmap resource not found. will use default value or env var.")
			r.opConfig.Parameters = make(map[string]string)
		} else {
			// Error reading the object - requeue the request.
			return opcontroller.ImmediateRetryResult, errors.Wrap(err, "failed to get operator's configmap")
		}
	} else {
		// Populate the operator's config
		r.opConfig.Parameters = opConfig.Data
	}

	serverVersion, err := r.context.Clientset.Discovery().ServerVersion()
	if err != nil {
		return opcontroller.ImmediateRetryResult, errors.Wrap(err, "failed to get server version")
	}

	ownerRef, err := k8sutil.GetDeploymentOwnerReference(r.opManagerContext, r.context.Clientset, os.Getenv(k8sutil.PodNameEnvVar), r.opConfig.OperatorNamespace)
	if err != nil {
		logger.Warningf("could not find deployment owner reference to assign to csi drivers. %v", err)
	}
	if ownerRef != nil {
		blockOwnerDeletion := false
		ownerRef.BlockOwnerDeletion = &blockOwnerDeletion
	}

	ownerInfo := k8sutil.NewOwnerInfoWithOwnerRef(ownerRef, r.opConfig.OperatorNamespace)
	// create an empty config map. config map will be filled with data
	// later when clusters have mons
	err = CreateCsiConfigMap(r.opConfig.OperatorNamespace, r.context.Clientset, ownerInfo)
	if err != nil {
		return opcontroller.ImmediateRetryResult, errors.Wrap(err, "failed creating csi config map")
	}

	err = peermap.CreateOrUpdateConfig(r.opManagerContext, r.context, &peermap.PeerIDMappings{})
	if err != nil {
		return opcontroller.ImmediateRetryResult, errors.Wrap(err, "failed to create pool ID mapping config map")
	}

	err = r.validateAndConfigureDrivers(serverVersion, ownerInfo)
	if err != nil {
		return opcontroller.ImmediateRetryResult, errors.Wrap(err, "failed configure ceph csi")
	}

	return reconcile.Result{}, nil
}