package prometheusctl

import (
	"reflect"

	monitoringv1 "github.com/prometheus-operator/prometheus-operator/pkg/apis/monitoring/v1"

	"edge-infra.dev/pkg/k8s/meta"

	"sigs.k8s.io/controller-runtime/pkg/event"
	"sigs.k8s.io/controller-runtime/pkg/predicate"
)

var (
	prometheusKind = reflect.TypeOf(monitoringv1.Prometheus{}).Name()
)

func predicates(prometheus meta.NamespacedObjectReference) predicate.Funcs {
	return predicate.Funcs{
		UpdateFunc: func(e event.UpdateEvent) bool {
			// process updates to the spec of Prometheus objects that we care about
			if e.ObjectNew.GetObjectKind().GroupVersionKind().Kind == prometheusKind &&
				e.ObjectOld.GetGeneration() != e.ObjectNew.GetGeneration() &&
				e.ObjectNew.GetName() == prometheus.Name &&
				e.ObjectNew.GetNamespace() == prometheus.Namespace {
				return true
			}

			// otherwise, we want to reconcile `*Monitor` objects if their annotations
			// change and they contain the annotation that we care about
			if e.ObjectNew.GetObjectKind().GroupVersionKind().Kind != prometheusKind &&
				e.ObjectNew.GetResourceVersion() != e.ObjectOld.GetResourceVersion() &&
				e.ObjectNew.GetAnnotations()[allowedMetrics] != "" {
				return true
			}

			return false
		},
		CreateFunc: func(e event.CreateEvent) bool {
			// only process the prometheus that we care about
			if e.Object.GetObjectKind().GroupVersionKind().Kind == prometheusKind &&
				e.Object.GetName() == prometheus.Name &&
				e.Object.GetNamespace() == prometheus.Namespace {
				return true
			}

			// otherwise, we want to reconcile `*Monitor` objects if they have the annotation
			// we care ab out
			if e.Object.GetAnnotations()[allowedMetrics] != "" {
				return true
			}

			return false
		},
		DeleteFunc: func(_ event.DeleteEvent) bool {
			return true
		},
	}
}