// Collection[T] merging equal objects into one record
// in the resulting Collection
func JoinCollection[T any](cs []Collection[T], opts ...CollectionOption) Collection[T] {
	o := buildCollectionOptions(opts...)
	if o.name == "" {
		o.name = fmt.Sprintf("Join[%v]", ptr.TypeName[T]())
	}
	synced := make(chan struct{})
	c := slices.Map(cs, func(e Collection[T]) internalCollection[T] {

	e := Event[O]{
		Event: o.Event,
	}
	if o.Old != nil {
		e.Old = ptr.Of(any(*o.Old).(O))
	}
	if o.New != nil {
		e.New = ptr.Of(any(*o.New).(O))
	}
	return e
}

func buildCollectionOptions(opts ...CollectionOption) collectionOptions {
	c := &collectionOptions{}
	for _, o := range opts {
		o(c)
	}
	if c.stop == nil {
		c.stop = make(chan struct{})
	}
	return *c
}

// informer for a Collection of type controllers.Object
func WrapClient[I controllers.ComparableObject](c kclient.Informer[I], opts ...CollectionOption) Collection[I] {
	o := buildCollectionOptions(opts...)
	if o.name == "" {
		o.name = fmt.Sprintf("NewInformer[%v]", ptr.TypeName[I]())
	}
	h := &informer[I]{
		inf:            c,
		log:            log.WithLabels("owner", o.name),

	hm := func(ctx HandlerContext, i I) []O {
		res := hf(ctx, i)
		if res == nil {
			return nil
		}
		return []O{*res}
	}
	o := buildCollectionOptions(opts...)
	if o.name == "" {
		o.name = fmt.Sprintf("Collection[%v,%v]", ptr.TypeName[I](), ptr.TypeName[O]())
	}
	return newManyCollection[I, O](c, hm, o)
}