// from https://github.com/vercel/next.js/blob/canary/packages/next/src/client/components/redirect-error.ts

export const RedirectStatusCode = {
  SeeOther: 303,
  TemporaryRedirect: 307,
  PermanentRedirect: 308,
} as const;

export type RedirectStatusCode = (typeof RedirectStatusCode)[keyof typeof RedirectStatusCode];

export const REDIRECT_ERROR_CODE = 'NEXT_REDIRECT';

export enum RedirectType {
  push = 'push',
  replace = 'replace',
}

export type RedirectError = Error & {
  digest: `${typeof REDIRECT_ERROR_CODE};${RedirectType};${string};${RedirectStatusCode};`;
};

/**
 * Checks an error to determine if it's an error generated by the
 * `redirect(url)` helper.
 *
 * @param error the error that may reference a redirect error
 * @returns true if the error is a redirect error
 */
export function isRedirectError(error: unknown): error is RedirectError {
  if (typeof error !== 'object' || error === null || !('digest' in error) || typeof error.digest !== 'string') {
    return false;
  }

  const digest = error.digest.split(';');
  const [errorCode, type] = digest;
  const destination = digest.slice(2, -2).join(';');
  const status = digest.at(-2);

  const statusCode = Number(status);

  return (
    errorCode === REDIRECT_ERROR_CODE &&
    (type === 'replace' || type === 'push') &&
    typeof destination === 'string' &&
    !isNaN(statusCode) &&
    Object.values(RedirectStatusCode).includes(statusCode as RedirectStatusCode)
  );
}

export function getRedirectStatus(error: RedirectError): RedirectStatusCode {
  const status = error.digest.split(';').at(-2);
  return Number(status) as RedirectStatusCode;
}