import { ValidationOptions } from "../ValidationOptions";
import { buildMessage, ValidateBy } from "../common/ValidateBy";

export const IS_EMPTY = "isEmpty";

/**
 * Checks if given value is empty (=== '', === null, === undefined).
 */
export function isEmpty(value: unknown): boolean {
    return value === "" || value === null || value === undefined;
}

/**
 * Checks if given value is empty (=== '', === null, === undefined).
 */
export function IsEmpty(validationOptions?: ValidationOptions): PropertyDecorator {
    return ValidateBy(
        {
            name: IS_EMPTY,
            validator: {
                validate: (value, args): boolean => isEmpty(value),
                defaultMessage: buildMessage(
                    (eachPrefix) => eachPrefix + "$property must be empty",
                    validationOptions
                )
            }
        },
        validationOptions
    );
}