import {
  registerDecorator,
  ValidationArguments,
  ValidationOptions,
  ValidatorConstraint,
  ValidatorConstraintInterface,
} from "class-validator";
import { normalizeMoneyAmountString } from "src/utils/unicode-digits";

@ValidatorConstraint({ name: "isMoneyAmountString", async: false })
export class IsMoneyAmountStringConstraint
  implements ValidatorConstraintInterface
{
  validate(value: unknown): boolean {
    if (value == null || value === "") return true;
    if (typeof value !== "string") return false;
    const n = normalizeMoneyAmountString(value);
    if (!n) return false;
    return /^\d+(\.\d+)?$/.test(n);
  }

  defaultMessage(): string {
    return "Must be a non-negative amount (digits only, optional decimal).";
  }
}

export function IsMoneyAmountString(validationOptions?: ValidationOptions) {
  return (object: object, propertyName: string) => {
    registerDecorator({
      target: object.constructor,
      propertyName,
      options: validationOptions,
      constraints: [],
      validator: IsMoneyAmountStringConstraint,
    });
  };
}