/*
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"

	"k8s.io/apimachinery/pkg/runtime"

	"kubevirt.io/containerized-data-importer/pkg/common"
	"kubevirt.io/controller-lifecycle-operator-sdk/pkg/sdk/callbacks"

	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"
	sdk "kubevirt.io/controller-lifecycle-operator-sdk/pkg/sdk"
	"sigs.k8s.io/controller-runtime/pkg/client"
)

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
}

// delete when we no longer support <= 1.27.0
func reconcileSELinuxPerms(args *callbacks.ReconcileCallbackArgs) error {
	if args.State != callbacks.ReconcileStatePostRead {
		return nil
	}

	sa := args.DesiredObject.(*corev1.ServiceAccount)
	if sa.Name != common.ControllerServiceAccountName {
		return nil
	}

	scc := &secv1.SecurityContextConstraints{}
	err := args.Client.Get(context.TODO(), client.ObjectKey{Name: sccName}, scc)
	if err != nil {
		if meta.IsNoMatchError(err) {
			return nil
		}

		return err
	}

	if scc.SELinuxContext.Type != secv1.SELinuxStrategyRunAsAny {
		scc.SELinuxContext.Type = secv1.SELinuxStrategyRunAsAny

		if err = args.Client.Update(context.TODO(), scc); err != nil {
			return err
		}
	}

	return nil
}