package util

import (
	"reflect"
)

// Implements get reflect.Zero(T) and (o).Implements(T)
func Implements[T any](o any) (T, bool) {
	iface := reflect.TypeOf((*T)(nil)).Elem()

	reflectType := reflect.TypeOf(o)

	if alreadyReflectType, ok := o.(reflect.Type); ok {
		reflectType = alreadyReflectType
		o = reflect.Zero(reflectType).Interface()
	} else if alreadyReflectValue, ok := o.(reflect.Value); ok {
		reflectType = alreadyReflectValue.Type()
		o = alreadyReflectValue.Interface()
	}

	if reflectType.Implements(iface) {
		if reflectType.Kind() == reflect.Interface {
			return *reflect.New(iface).Interface().(*T), true
		}
		return o.(T), true
	} else {
		return *reflect.New(iface).Interface().(*T), false
	}
}

// PointerImplements get reflect.New(T) and (&o).Implements(T)
func PointerImplements[I any](o any) (reflect.Value, bool) {
	iface := reflect.TypeOf((*I)(nil)).Elem()

	reflectType := reflect.TypeOf(&o)
	if alreadyReflectType, ok := o.(reflect.Type); ok {
		reflectType = reflect.PointerTo(alreadyReflectType)
	} else if alreadyReflectValue, ok := o.(reflect.Value); ok {
		reflectType = reflect.PointerTo(alreadyReflectValue.Type())
	}

	reflectValue := reflect.New(reflectType.Elem())

	return reflectValue, reflectType.Implements(iface)
}