/*
Copyright 2022 The Knative 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.
*/

// Code generated by injection-gen. DO NOT EDIT.

package sample

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

	zap "go.uber.org/zap"
	v1 "k8s.io/api/core/v1"
	errors "k8s.io/apimachinery/pkg/api/errors"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	labels "k8s.io/apimachinery/pkg/labels"
	types "k8s.io/apimachinery/pkg/types"
	sets "k8s.io/apimachinery/pkg/util/sets"
	kubernetes "k8s.io/client-go/kubernetes"
	corev1 "k8s.io/client-go/listers/core/v1"
	cache "k8s.io/client-go/tools/cache"
	record "k8s.io/client-go/tools/record"
	controller "knative.dev/pkg/controller"
	logging "knative.dev/pkg/logging"
	pkgreconciler "knative.dev/pkg/reconciler"
)

// Interface defines the strongly typed interfaces to be implemented by a
// controller reconciling v1.Secret.
type Interface interface {
	// ReconcileKind implements custom logic to reconcile v1.Secret. Any changes
	// to the objects .Status or .Finalizers will be propagated to the stored
	// object. It is recommended that implementors do not call any update calls
	// for the Kind inside of ReconcileKind, it is the responsibility of the calling
	// controller to propagate those properties. The resource passed to ReconcileKind
	// will always have an empty deletion timestamp.
	ReconcileKind(ctx context.Context, o *v1.Secret) pkgreconciler.Event
}

// Finalizer defines the strongly typed interfaces to be implemented by a
// controller finalizing v1.Secret.
type Finalizer interface {
	// FinalizeKind implements custom logic to finalize v1.Secret. Any changes
	// to the objects .Status or .Finalizers will be ignored. Returning a nil or
	// Normal type reconciler.Event will allow the finalizer to be deleted on
	// the resource. The resource passed to FinalizeKind will always have a set
	// deletion timestamp.
	FinalizeKind(ctx context.Context, o *v1.Secret) pkgreconciler.Event
}

// ReadOnlyInterface defines the strongly typed interfaces to be implemented by a
// controller reconciling v1.Secret if they want to process resources for which
// they are not the leader.
type ReadOnlyInterface interface {
	// ObserveKind implements logic to observe v1.Secret.
	// This method should not write to the API.
	ObserveKind(ctx context.Context, o *v1.Secret) pkgreconciler.Event
}

// state is used to track the state of a reconciler in a single run.
type state struct {
	// key is the original reconciliation key from the queue.
	key string
	// namespace is the namespace split from the reconciliation key.
	namespace string
	// name is the name split from the reconciliation key.
	name string
	// reconciler is the reconciler.
	reconciler Interface
	// roi is the read only interface cast of the reconciler.
	roi ReadOnlyInterface
	// isROI (Read Only Interface) the reconciler only observes reconciliation.
	isROI bool
	// isLeader the instance of the reconciler is the elected leader.
	isLeader bool
}

type doReconcile func(ctx context.Context, o *v1.Secret) pkgreconciler.Event

// reconcilerImpl implements controller.Reconciler for v1.Secret resources.
type reconcilerImpl struct {
	// LeaderAwareFuncs is inlined to help us implement reconciler.LeaderAware.
	pkgreconciler.LeaderAwareFuncs

	// Client is used to write back status updates.
	Client kubernetes.Interface

	// Listers index properties about resources.
	Lister corev1.SecretLister

	// Recorder is an event recorder for recording Event resources to the
	// Kubernetes API.
	Recorder record.EventRecorder

	// configStore allows for decorating a context with config maps.
	// +optional
	configStore pkgreconciler.ConfigStore

	// reconciler is the implementation of the business logic of the resource.
	reconciler Interface

	// finalizerName is the name of the finalizer to reconcile.
	finalizerName string
}

// Check that our Reconciler implements controller.Reconciler.
var _ controller.Reconciler = (*reconcilerImpl)(nil)

// Check that our generated Reconciler is always LeaderAware.
var _ pkgreconciler.LeaderAware = (*reconcilerImpl)(nil)

func NewReconciler(ctx context.Context, logger *zap.SugaredLogger, client kubernetes.Interface, lister corev1.SecretLister, recorder record.EventRecorder, r Interface, options ...controller.Options) controller.Reconciler {
	// Check the options function input. It should be 0 or 1.
	if len(options) > 1 {
		logger.Fatal("Up to one options struct is supported, found: ", len(options))
	}

	// Fail fast when users inadvertently implement the other LeaderAware interface.
	// For the typed reconcilers, Promote shouldn't take any arguments.
	if _, ok := r.(pkgreconciler.LeaderAware); ok {
		logger.Fatalf("%T implements the incorrect LeaderAware interface. Promote() should not take an argument as genreconciler handles the enqueuing automatically.", r)
	}

	rec := &reconcilerImpl{
		LeaderAwareFuncs: pkgreconciler.LeaderAwareFuncs{
			PromoteFunc: func(bkt pkgreconciler.Bucket, enq func(pkgreconciler.Bucket, types.NamespacedName)) error {
				all, err := lister.List(labels.Everything())
				if err != nil {
					return err
				}
				for _, elt := range all {
					// TODO: Consider letting users specify a filter in options.
					enq(bkt, types.NamespacedName{
						Namespace: elt.GetNamespace(),
						Name:      elt.GetName(),
					})
				}
				return nil
			},
		},
		Client:        client,
		Lister:        lister,
		Recorder:      recorder,
		reconciler:    r,
		finalizerName: defaultFinalizerName,
	}

	for _, opts := range options {
		if opts.ConfigStore != nil {
			rec.configStore = opts.ConfigStore
		}
		if opts.FinalizerName != "" {
			rec.finalizerName = opts.FinalizerName
		}
		if opts.DemoteFunc != nil {
			rec.DemoteFunc = opts.DemoteFunc
		}
	}

	return rec
}

// Reconcile implements controller.Reconciler
func (r *reconcilerImpl) Reconcile(ctx context.Context, key string) error {
	logger := logging.FromContext(ctx)

	// Initialize the reconciler state. This will convert the namespace/name
	// string into a distinct namespace and name, determine if this instance of
	// the reconciler is the leader, and any additional interfaces implemented
	// by the reconciler. Returns an error is the resource key is invalid.
	s, err := newState(key, r)
	if err != nil {
		logger.Error("Invalid resource key: ", key)
		return nil
	}

	// If we are not the leader, and we don't implement either ReadOnly
	// observer interfaces, then take a fast-path out.
	if s.isNotLeaderNorObserver() {
		return controller.NewSkipKey(key)
	}

	// If configStore is set, attach the frozen configuration to the context.
	if r.configStore != nil {
		ctx = r.configStore.ToContext(ctx)
	}

	// Add the recorder to context.
	ctx = controller.WithEventRecorder(ctx, r.Recorder)

	// Get the resource with this namespace/name.

	getter := r.Lister.Secrets(s.namespace)

	original, err := getter.Get(s.name)

	if errors.IsNotFound(err) {
		// The resource may no longer exist, in which case we stop processing and call
		// the ObserveDeletion handler if appropriate.
		logger.Debugf("Resource %q no longer exists", key)
		if del, ok := r.reconciler.(pkgreconciler.OnDeletionInterface); ok {
			return del.ObserveDeletion(ctx, types.NamespacedName{
				Namespace: s.namespace,
				Name:      s.name,
			})
		}
		return nil
	} else if err != nil {
		return err
	}

	// Don't modify the informers copy.
	resource := original.DeepCopy()

	var reconcileEvent pkgreconciler.Event

	name, do := s.reconcileMethodFor(resource)
	// Append the target method to the logger.
	logger = logger.With(zap.String("targetMethod", name))
	switch name {
	case pkgreconciler.DoReconcileKind:
		// Set and update the finalizer on resource if r.reconciler
		// implements Finalizer.
		if resource, err = r.setFinalizerIfFinalizer(ctx, resource); err != nil {
			return fmt.Errorf("failed to set finalizers: %w", err)
		}

		// Reconcile this copy of the resource and then write back any status
		// updates regardless of whether the reconciliation errored out.
		reconcileEvent = do(ctx, resource)

	case pkgreconciler.DoFinalizeKind:
		// For finalizing reconcilers, if this resource being marked for deletion
		// and reconciled cleanly (nil or normal event), remove the finalizer.
		reconcileEvent = do(ctx, resource)

		if resource, err = r.clearFinalizer(ctx, resource, reconcileEvent); err != nil {
			return fmt.Errorf("failed to clear finalizers: %w", err)
		}

	case pkgreconciler.DoObserveKind:
		// Observe any changes to this resource, since we are not the leader.
		reconcileEvent = do(ctx, resource)

	}

	// Report the reconciler event, if any.
	if reconcileEvent != nil {
		var event *pkgreconciler.ReconcilerEvent
		if pkgreconciler.EventAs(reconcileEvent, &event) {
			logger.Infow("Returned an event", zap.Any("event", reconcileEvent))
			r.Recorder.Event(resource, event.EventType, event.Reason, event.Error())

			// the event was wrapped inside an error, consider the reconciliation as failed
			if _, isEvent := reconcileEvent.(*pkgreconciler.ReconcilerEvent); !isEvent {
				return reconcileEvent
			}
			return nil
		}

		if controller.IsSkipKey(reconcileEvent) {
			// This is a wrapped error, don't emit an event.
		} else if ok, _ := controller.IsRequeueKey(reconcileEvent); ok {
			// This is a wrapped error, don't emit an event.
		} else {
			logger.Errorw("Returned an error", zap.Error(reconcileEvent))
			r.Recorder.Event(resource, v1.EventTypeWarning, "InternalError", reconcileEvent.Error())
		}
		return reconcileEvent
	}

	return nil
}

// updateFinalizersFiltered will update the Finalizers of the resource.
// TODO: this method could be generic and sync all finalizers. For now it only
// updates defaultFinalizerName or its override.
func (r *reconcilerImpl) updateFinalizersFiltered(ctx context.Context, resource *v1.Secret, desiredFinalizers sets.String) (*v1.Secret, error) {
	// Don't modify the informers copy.
	existing := resource.DeepCopy()

	var finalizers []string

	// If there's nothing to update, just return.
	existingFinalizers := sets.NewString(existing.Finalizers...)

	if desiredFinalizers.Has(r.finalizerName) {
		if existingFinalizers.Has(r.finalizerName) {
			// Nothing to do.
			return resource, nil
		}
		// Add the finalizer.
		finalizers = append(existing.Finalizers, r.finalizerName)
	} else {
		if !existingFinalizers.Has(r.finalizerName) {
			// Nothing to do.
			return resource, nil
		}
		// Remove the finalizer.
		existingFinalizers.Delete(r.finalizerName)
		finalizers = existingFinalizers.List()
	}

	mergePatch := map[string]interface{}{
		"metadata": map[string]interface{}{
			"finalizers":      finalizers,
			"resourceVersion": existing.ResourceVersion,
		},
	}

	patch, err := json.Marshal(mergePatch)
	if err != nil {
		return resource, err
	}

	patcher := r.Client.CoreV1().Secrets(resource.Namespace)

	resourceName := resource.Name
	updated, err := patcher.Patch(ctx, resourceName, types.MergePatchType, patch, metav1.PatchOptions{})
	if err != nil {
		r.Recorder.Eventf(existing, v1.EventTypeWarning, "FinalizerUpdateFailed",
			"Failed to update finalizers for %q: %v", resourceName, err)
	} else {
		r.Recorder.Eventf(updated, v1.EventTypeNormal, "FinalizerUpdate",
			"Updated %q finalizers", resource.GetName())
	}
	return updated, err
}

func (r *reconcilerImpl) setFinalizerIfFinalizer(ctx context.Context, resource *v1.Secret) (*v1.Secret, error) {
	if _, ok := r.reconciler.(Finalizer); !ok {
		return resource, nil
	}

	finalizers := sets.NewString(resource.Finalizers...)

	// If this resource is not being deleted, mark the finalizer.
	if resource.GetDeletionTimestamp().IsZero() {
		finalizers.Insert(r.finalizerName)
	}

	// Synchronize the finalizers filtered by r.finalizerName.
	return r.updateFinalizersFiltered(ctx, resource, finalizers)
}

func (r *reconcilerImpl) clearFinalizer(ctx context.Context, resource *v1.Secret, reconcileEvent pkgreconciler.Event) (*v1.Secret, error) {
	if _, ok := r.reconciler.(Finalizer); !ok {
		return resource, nil
	}
	if resource.GetDeletionTimestamp().IsZero() {
		return resource, nil
	}

	finalizers := sets.NewString(resource.Finalizers...)

	if reconcileEvent != nil {
		var event *pkgreconciler.ReconcilerEvent
		if pkgreconciler.EventAs(reconcileEvent, &event) {
			if event.EventType == v1.EventTypeNormal {
				finalizers.Delete(r.finalizerName)
			}
		}
	} else {
		finalizers.Delete(r.finalizerName)
	}

	// Synchronize the finalizers filtered by r.finalizerName.
	return r.updateFinalizersFiltered(ctx, resource, finalizers)
}

func newState(key string, r *reconcilerImpl) (*state, error) {
	// Convert the namespace/name string into a distinct namespace and name.
	namespace, name, err := cache.SplitMetaNamespaceKey(key)
	if err != nil {
		return nil, fmt.Errorf("invalid resource key: %s", key)
	}

	roi, isROI := r.reconciler.(ReadOnlyInterface)

	isLeader := r.IsLeaderFor(types.NamespacedName{
		Namespace: namespace,
		Name:      name,
	})

	return &state{
		key:        key,
		namespace:  namespace,
		name:       name,
		reconciler: r.reconciler,
		roi:        roi,
		isROI:      isROI,
		isLeader:   isLeader,
	}, nil
}

// isNotLeaderNorObserver checks to see if this reconciler with the current
// state is enabled to do any work or not.
// isNotLeaderNorObserver returns true when there is no work possible for the
// reconciler.
func (s *state) isNotLeaderNorObserver() bool {
	if !s.isLeader && !s.isROI {
		// If we are not the leader, and we don't implement the ReadOnly
		// interface, then take a fast-path out.
		return true
	}
	return false
}

func (s *state) reconcileMethodFor(o *v1.Secret) (string, doReconcile) {
	if o.GetDeletionTimestamp().IsZero() {
		if s.isLeader {
			return pkgreconciler.DoReconcileKind, s.reconciler.ReconcileKind
		} else if s.isROI {
			return pkgreconciler.DoObserveKind, s.roi.ObserveKind
		}
	} else if fin, ok := s.reconciler.(Finalizer); s.isLeader && ok {
		return pkgreconciler.DoFinalizeKind, fin.FinalizeKind
	}
	return "unknown", nil
}
