package serverevents

import "encoding/json"

func CreateMetaDataFilter[T any](c IContext, metaDataSelector func(IContext) T, vgl func(a T, b T) bool) func(context IContext) bool {
	return func(context IContext) bool {
		metaA := metaDataSelector(c)
		metaB := metaDataSelector(context)
		return vgl(metaA, metaB)
	}
}

func MetadataAs[T any](context IContext, key string) (T, bool) {
	tmp, _ := context.Get(key)
	return ValueAs[T](tmp)
}

func ValueAs[T any](data any) (T, bool) {
	var v T
	str, err := json.Marshal(data)
	if err != nil {
		return v, false
	}
	err = json.Unmarshal(str, &v)
	if err != nil {
		return v, false
	}
	return v, true
}