package domain

import (
	"git.sxidc.com/go-tools/utils/reflectutils"
	"git.sxidc.com/service-supports/fserr"
	"reflect"
)

type Object interface{}

func HasField(object Object, fieldName string) bool {
	return hasField(object, fieldName)
}

func SetField[T any](object Object, fieldName string, value T) error {
	if object == nil {
		return fserr.New("领域对象为nil")
	}

	fieldValue, err := getFieldValue(object, fieldName)
	if err != nil {
		return err
	}

	if !fieldValue.IsValid() || !fieldValue.CanSet() {
		return fserr.New("领域对象" + fieldValue.Type().String() + "的字段" + fieldName + "无法赋值")
	}

	fieldValue.Set(reflect.ValueOf(value))

	return nil
}

func Field[T any](object Object, fieldName string) (T, error) {
	var zero T

	if object == nil {
		return zero, fserr.New("领域对象为nil")
	}

	fieldValue, err := getFieldValue(object, fieldName)
	if err != nil {
		return zero, err
	}

	if !fieldValue.IsValid() {
		return zero, fserr.New("领域对象" + fieldValue.Type().String() + "的字段" + fieldName + "无法赋值")
	}

	retValue, ok := fieldValue.Interface().(T)
	if !ok {
		return zero, err
	}

	return retValue, nil
}

func ToConcrete[T Object](object Object) (T, error) {
	var zero T

	if object == nil {
		return zero, fserr.New("领域对象为nil")
	}

	concrete, ok := object.(T)
	if !ok {
		return zero, fserr.New("领域对象转化失败")
	}

	return concrete, nil
}

func hasField(object Object, fieldName string) bool {
	if object == nil {
		return false
	}

	objectValue := reflect.ValueOf(object)
	if reflectutils.IsValueStructOrStructPointer(objectValue) {
		return false
	}

	fieldValue := reflectutils.PointerValueElem(objectValue).FieldByName(fieldName)
	if !fieldValue.IsValid() {
		return false
	}

	return true
}

func getFieldValue(object Object, fieldName string) (*reflect.Value, error) {
	if object == nil {
		return nil, fserr.New("领域对象为nil")
	}

	objectValue := reflect.ValueOf(object)

	if reflectutils.IsValueStructOrStructPointer(objectValue) {
		return nil, fserr.New("领域对象必须是结构或结构指针")
	}

	fieldValue := reflectutils.PointerValueElem(objectValue).FieldByName(fieldName)

	return &fieldValue, nil
}