import { ValidationOptions } from "../ValidationOptions";
import { ValidationMetadataArgs } from "../../metadata/ValidationMetadataArgs";
import { ValidationTypes } from "../../validation/ValidationTypes";
import { ValidationMetadata } from "../../metadata/ValidationMetadata";
import { getMetadataStorage } from "../../metadata/MetadataStorage";

/**
 * Checks if value is missing and if so, ignores all validators.
 */
export function IsOptional(validationOptions?: ValidationOptions): PropertyDecorator {
    return function (object: object, propertyName: string): void {
        const args: ValidationMetadataArgs = {
            type: ValidationTypes.CONDITIONAL_VALIDATION,
            target: object.constructor,
            propertyName: propertyName,
            constraints: [(object: any, value: any): boolean => {
                return object[propertyName] !== null && object[propertyName] !== undefined;
            }],
            validationOptions: validationOptions
        };
        getMetadataStorage().addValidationMetadata(new ValidationMetadata(args));
    };
}