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

export const IS_DECIMAL = "isDecimal";

/**
 * Checks if the string is a valid decimal.
 * If given value is not a string, then it returns false.
 */
export function isDecimal(value: unknown, options?: ValidatorJS.IsDecimalOptions): boolean {
    return typeof value === "string" && ValidatorJS.isDecimal(value, options);
}

/**
 * Checks if the string contains only letters and numbers.
 * If given value is not a string, then it returns false.
 */
export function IsDecimal(options?: ValidatorJS.IsDecimalOptions, validationOptions?: ValidationOptions): PropertyDecorator {
    return ValidateBy(
        {
            name: IS_DECIMAL,
            constraints: [options],
            validator: {
                validate: (value, args): boolean => isDecimal(value, args.constraints[0]),
                defaultMessage: buildMessage(
                    (eachPrefix) => eachPrefix + "$property is not a valid decimal number.",
                    validationOptions
                )
            }
        },
        validationOptions
    );
}