package predicate

import (
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/runtime"
)

// Func is a generic function used to filter various types of resources.
type Func func(obj runtime.Object) bool

// Funcs is a list of predicates to be AND'd together.
type Funcs []Func

// Evaluate will evaluate all the predicate functions in order, AND'ing
// together the results.
func (f Funcs) Evaluate(obj runtime.Object) bool {
	for _, fn := range f {
		if !fn(obj) {
			return false
		}
	}
	return true
}

// An ExtractorFunc applies a transformation to a runtime.Object and creates a
// predicate function based on the result of the transformation.
// This can be used to apply complex lookup logic to determine which resources
// should be enqueued if another resource being watched changes, for example,
// enqueuing all Certificate resources that own a CertificateRequest that has
// been observed, or enqueuing all Certificate resources that specify
// `status.nextPrivateKeySecretName` as the name of the Secret being processed.
type ExtractorFunc func(obj runtime.Object) Func

// ExtractResourceName is a helper function used to extract a name from a
// metav1.Object being enqueued to construct a Func that is variadic
// based on a string value.
func ExtractResourceName(p func(s string) Func) ExtractorFunc {
	return func(obj runtime.Object) Func {
		metaObj := obj.(metav1.Object)
		return p(metaObj.GetName())
	}
}