package events

import (
	corev1 "k8s.io/api/core/v1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"

	eventspb "github.com/argoproj/argo-cd/v3/pkg/apiclient/events"
)

// K8sEventListToAPIEventList converts a Kubernetes EventList into the typed
// Argo CD events API representation. A nil input is mapped to an empty list so
// callers can return the result directly without a nil-check.
func K8sEventListToAPIEventList(in *corev1.EventList) *eventspb.EventList {
	if in == nil {
		return &eventspb.EventList{}
	}

	out := &eventspb.EventList{
		Metadata: in.ListMeta,
		Items:    make([]eventspb.Event, 0, len(in.Items)),
	}
	for i := range in.Items {
		out.Items = append(out.Items, k8sEventToAPIEvent(&in.Items[i]))
	}
	return out
}

func k8sEventToAPIEvent(in *corev1.Event) eventspb.Event {
	out := eventspb.Event{
		Metadata:            in.ObjectMeta,
		InvolvedObject:      k8sObjectReferenceToAPIObjectReference(in.InvolvedObject),
		Reason:              in.Reason,
		Message:             in.Message,
		Source:              k8sEventSourceToAPIEventSource(in.Source),
		FirstTimestamp:      in.FirstTimestamp,
		LastTimestamp:       in.LastTimestamp,
		Count:               in.Count,
		Type:                in.Type,
		EventTime:           in.EventTime,
		Series:              k8sEventSeriesPtrToAPIEventSeriesPtr(in.Series),
		Action:              in.Action,
		Related:             k8sObjectReferencePtrToAPIObjectReferencePtr(in.Related),
		ReportingController: in.ReportingController,
		ReportingInstance:   in.ReportingInstance,
	}
	// events.k8s.io/v1 events keep occurrence data in EventTime and Series; fill the legacy fields like kubectl does
	if in.Series != nil {
		out.Count = in.Series.Count
		if !in.Series.LastObservedTime.IsZero() {
			out.LastTimestamp = metav1.NewTime(in.Series.LastObservedTime.Time)
		}
	} else if out.Count == 0 && !in.EventTime.IsZero() {
		out.Count = 1
	}
	if out.FirstTimestamp.IsZero() && !in.EventTime.IsZero() {
		out.FirstTimestamp = metav1.NewTime(in.EventTime.Time)
	}
	if out.LastTimestamp.IsZero() && !in.EventTime.IsZero() {
		out.LastTimestamp = metav1.NewTime(in.EventTime.Time)
	}
	return out
}

func k8sEventSourceToAPIEventSource(in corev1.EventSource) eventspb.EventSource {
	return eventspb.EventSource{
		Component: in.Component,
		Host:      in.Host,
	}
}

func k8sEventSeriesPtrToAPIEventSeriesPtr(in *corev1.EventSeries) *eventspb.EventSeries {
	if in == nil {
		return nil
	}
	return &eventspb.EventSeries{
		Count:            in.Count,
		LastObservedTime: in.LastObservedTime,
	}
}

func k8sObjectReferenceToAPIObjectReference(in corev1.ObjectReference) eventspb.ObjectReference {
	return eventspb.ObjectReference{
		Kind:            in.Kind,
		Namespace:       in.Namespace,
		Name:            in.Name,
		UID:             string(in.UID),
		APIVersion:      in.APIVersion,
		ResourceVersion: in.ResourceVersion,
		FieldPath:       in.FieldPath,
	}
}

func k8sObjectReferencePtrToAPIObjectReferencePtr(in *corev1.ObjectReference) *eventspb.ObjectReference {
	if in == nil {
		return nil
	}
	out := k8sObjectReferenceToAPIObjectReference(*in)
	return &out
}