/*
Copyright 2018 The CDI 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 controller

import (
	"context"
	"encoding/json"
	"fmt"
	"reflect"

	routev1 "github.com/openshift/api/route/v1"
	secv1 "github.com/openshift/api/security/v1"
	appsv1 "k8s.io/api/apps/v1"
	corev1 "k8s.io/api/core/v1"
	extv1 "k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1"
	"k8s.io/apimachinery/pkg/api/errors"
	"k8s.io/apimachinery/pkg/api/meta"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/runtime"
	"k8s.io/apimachinery/pkg/types"
	"sigs.k8s.io/controller-runtime/pkg/client"
	"sigs.k8s.io/controller-runtime/pkg/handler"
	"sigs.k8s.io/controller-runtime/pkg/reconcile"
	"sigs.k8s.io/controller-runtime/pkg/source"

	cdiv1 "kubevirt.io/containerized-data-importer-api/pkg/apis/core/v1beta1"
	"kubevirt.io/containerized-data-importer/pkg/apiserver"
	"kubevirt.io/containerized-data-importer/pkg/common"
	cc "kubevirt.io/containerized-data-importer/pkg/controller/common"
	"kubevirt.io/containerized-data-importer/pkg/operator"
	"kubevirt.io/containerized-data-importer/pkg/util"
	sdk "kubevirt.io/controller-lifecycle-operator-sdk/pkg/sdk"
	"kubevirt.io/controller-lifecycle-operator-sdk/pkg/sdk/callbacks"
)

const (
	// SCCAnnotation is the annotation listing SCCs for a SA
	SCCAnnotation = "cdi-scc"
)

// delete when we no longer support <= 1.12.0
func reconcileDeleteSecrets(args *callbacks.ReconcileCallbackArgs) error {
	if args.State != callbacks.ReconcileStatePostRead {
		return nil
	}

	deployment := args.CurrentObject.(*appsv1.Deployment)
	if !isControllerDeployment(deployment) {
		return nil
	}

	for _, s := range []string{"cdi-api-server-cert",
		"cdi-upload-proxy-ca-key",
		"cdi-upload-proxy-server-key",
		"cdi-upload-server-ca-key",
		"cdi-upload-server-client-ca-key",
		"cdi-upload-server-client-key",
	} {
		secret := &corev1.Secret{}
		key := client.ObjectKey{Namespace: args.Namespace, Name: s}
		err := args.Client.Get(context.TODO(), key, secret)
		if errors.IsNotFound(err) {
			continue
		}

		if err != nil {
			return err
		}

		err = args.Client.Delete(context.TODO(), secret)
		cr := args.Resource.(runtime.Object)
		if err != nil {
			args.Recorder.Event(cr, corev1.EventTypeWarning, deleteResourceFailed, fmt.Sprintf("Failed to delete secret %s, %v", s, err))
			return err
		}
		args.Recorder.Event(cr, corev1.EventTypeNormal, deleteResourceSuccess, fmt.Sprintf("Deleted secret %s successfully", s))
	}

	return nil
}

// delete when we no longer support <= 1.13.3
func reconcileServiceAccountRead(args *callbacks.ReconcileCallbackArgs) error {
	if args.State != callbacks.ReconcileStatePostRead {
		return nil
	}

	do := args.DesiredObject.(*corev1.ServiceAccount)
	co := args.CurrentObject.(*corev1.ServiceAccount)

	delete(co.Annotations, SCCAnnotation)

	val, exists := do.Annotations[SCCAnnotation]
	if exists {
		if co.Annotations == nil {
			co.Annotations = make(map[string]string)
		}
		co.Annotations[SCCAnnotation] = val
	}

	return nil
}

// delete when we no longer support <= 1.13.3
func reconcileServiceAccounts(args *callbacks.ReconcileCallbackArgs) error {
	switch args.State {
	case callbacks.ReconcileStatePreCreate, callbacks.ReconcileStatePreUpdate, callbacks.ReconcileStatePostDelete, callbacks.ReconcileStateOperatorDelete:
	default:
		return nil
	}

	var sa *corev1.ServiceAccount
	if args.CurrentObject != nil {
		sa = args.CurrentObject.(*corev1.ServiceAccount)
	} else if args.DesiredObject != nil {
		sa = args.DesiredObject.(*corev1.ServiceAccount)
	} else {
		args.Logger.Info("Received callback with no desired/current object")
		return nil
	}

	desiredSCCs := []string{}
	saName := fmt.Sprintf("system:serviceaccount:%s:%s", sa.Namespace, sa.Name)

	switch args.State {
	case callbacks.ReconcileStatePreCreate, callbacks.ReconcileStatePreUpdate:
		val, exists := sa.Annotations[SCCAnnotation]
		if exists {
			if err := json.Unmarshal([]byte(val), &desiredSCCs); err != nil {
				args.Logger.Error(err, "Error unmarshalling data")
				return err
			}
		}
	default:
		// want desiredSCCs empty because deleting resource/CDI
	}

	listObj := &secv1.SecurityContextConstraintsList{}
	if err := args.Client.List(context.TODO(), listObj, &client.ListOptions{}); err != nil {
		if meta.IsNoMatchError(err) {
			// not openshift
			return nil
		}
		args.Logger.Error(err, "Error listing SCCs")
		return err
	}

	for _, scc := range listObj.Items {
		desiredUsers := []string{}
		add := sdk.ContainsStringValue(desiredSCCs, scc.Name)
		seenUser := false

		for _, u := range scc.Users {
			if u == saName {
				seenUser = true
				if !add {
					continue
				}
			}
			desiredUsers = append(desiredUsers, u)
		}

		if add && !seenUser {
			desiredUsers = append(desiredUsers, saName)
		}

		if !reflect.DeepEqual(desiredUsers, scc.Users) {
			args.Logger.Info("Doing SCC update", "name", scc.Name, "desired", desiredUsers, "current", scc.Users)
			scc.Users = desiredUsers
			if err := args.Client.Update(context.TODO(), &scc); err != nil {
				args.Logger.Error(err, "Error updating SCC")
				return err
			}
		}
	}

	return nil
}

// delete when we no longer support <= 1.21.0
func reconcileInitializeCRD(args *callbacks.ReconcileCallbackArgs) error {
	if args.State != callbacks.ReconcileStatePreUpdate {
		return nil
	}

	crd := args.CurrentObject.(*extv1.CustomResourceDefinition)
	crd.Spec.PreserveUnknownFields = false

	return nil
}

func reconcileRemainingRelationshipLabels(args *callbacks.ReconcileCallbackArgs) error {
	if args.State != callbacks.ReconcileStatePostRead {
		return nil
	}

	deployment := args.CurrentObject.(*appsv1.Deployment)
	if !isControllerDeployment(deployment) || !sdk.CheckDeploymentReady(deployment) {
		return nil
	}
	namespace := deployment.GetNamespace()
	cr := args.Resource.(*cdiv1.CDI)
	installerLabels := util.GetRecommendedInstallerLabelsFromCr(cr)
	remainingResources := []client.Object{
		&corev1.ConfigMap{
			ObjectMeta: metav1.ObjectMeta{
				Name:      operator.ConfigMapName,
				Namespace: namespace,
			},
		},
		&corev1.ConfigMap{
			ObjectMeta: metav1.ObjectMeta{
				Name:      common.CDIControllerLeaderElectionHelperName,
				Namespace: namespace,
			},
		},
		&corev1.Secret{
			ObjectMeta: metav1.ObjectMeta{
				Name:      apiserver.APISigningKeySecretName,
				Namespace: namespace,
			},
		},
		&routev1.Route{
			ObjectMeta: metav1.ObjectMeta{
				Name:      uploadProxyRouteName,
				Namespace: namespace,
			},
		},
		&secv1.SecurityContextConstraints{
			ObjectMeta: metav1.ObjectMeta{
				Name: sccName,
			},
		},
	}

	for _, k := range remainingResources {
		nn := client.ObjectKeyFromObject(k)
		if err := args.Client.Get(context.TODO(), nn, k); err != nil {
			if errors.IsNotFound(err) || meta.IsNoMatchError(err) {
				// Doesn't exist or CRD not installed, we're fine
				continue
			}
			return err
		}
		// Exists, lets update labels if needed
		labelsCopy := util.MergeLabels(k.GetLabels(), map[string]string{})
		util.SetRecommendedLabels(k, installerLabels, "cdi-operator")
		if !reflect.DeepEqual(labelsCopy, k.GetLabels()) {
			if err := args.Client.Update(context.TODO(), k); err != nil {
				return err
			}
		}
	}

	return nil
}

// Delete after we no longer want to include CDI CRD v1alpha1 version in release YAMLs
// Special code needed because we're not the owner of this object.
func (r *ReconcileCDI) watchCDICRD() error {
	if err := r.controller.Watch(&source.Kind{Type: &extv1.CustomResourceDefinition{}}, handler.EnqueueRequestsFromMapFunc(
		func(obj client.Object) []reconcile.Request {
			name := obj.GetName()
			if name != "cdis.cdi.kubevirt.io" {
				return nil
			}
			cr, err := cc.GetActiveCDI(r.client)
			if err != nil {
				return nil
			}
			return []reconcile.Request{
				{
					NamespacedName: types.NamespacedName{
						Namespace: "",
						Name:      cr.Name,
					},
				},
			}
		},
	)); err != nil {
		return err
	}

	return nil
}

// ReconcileCDICRD monitors the CDI CRD and removes the alpha version from it.
// Delete after we no longer want to include CDI CRD v1alpha1 version in release YAMLs
// Remove alpha as a version from the CDI CRD
func reconcileCDICRD(args *callbacks.ReconcileCallbackArgs) error {
	if args.State != callbacks.ReconcileStatePostRead {
		return nil
	}
	deployment := args.CurrentObject.(*appsv1.Deployment)
	if !isControllerDeployment(deployment) {
		return nil
	}

	crd := &extv1.CustomResourceDefinition{}
	crdKey := client.ObjectKey{Namespace: "", Name: "cdis.cdi.kubevirt.io"}
	err := args.Client.Get(context.TODO(), crdKey, crd)
	crdCopy := crd.DeepCopy()
	if err != nil {
		if errors.IsNotFound(err) {
			args.Logger.Info("CDI CRD does not exist")
			return nil
		}
		args.Logger.Error(err, "Failed to get CDI CRD")
		return err
	}

	desiredVersion := newestVersion(crd)
	if olderVersionsExist(desiredVersion, crd) {
		args.Logger.Info("Old version is in CDI CRD status.storedVersion, rewriting objects and removing...")
		if !desiredIsStorage(desiredVersion, crd) {
			return err
		}
		if err := rewriteOldObjects(args, desiredVersion, crd); err != nil {
			return err
		}
		if err := removeStoredVersion(args, desiredVersion, crd); err != nil {
			return err
		}
	} else {
		removeOldVersions(desiredVersion, crd)
		if !reflect.DeepEqual(crdCopy, crd) {
			args.Logger.Info("Old version not in CDI CRD status.storedVersion, removing also from CRD spec")
			if err := args.Client.Update(context.TODO(), crd); err != nil {
				return err
			}
		}
	}
	return nil
}

// Delete after we no longer want to include CDI CRD v1alpha1 version in release YAMLs
func removeOldVersions(desiredVersion string, crd *extv1.CustomResourceDefinition) *extv1.CustomResourceDefinition {
	newVersions := make([]extv1.CustomResourceDefinitionVersion, 0)
	for _, version := range crd.Spec.Versions {
		if version.Name == desiredVersion {
			newVersions = append(newVersions, version)
		}
	}
	crd.Spec.Versions = newVersions
	return crd
}