import { z } from "zod";

const CODE_BLOCK_PATTERN = /```[\s\S]*?```/g;
const MATHJAX_PATTERN = /\$\$[^"]*?\$\$/g;

const stripWrappedContent = (value: string): string =>
  value.replaceAll(CODE_BLOCK_PATTERN, "").replaceAll(MATHJAX_PATTERN, "");

const containsForbiddenCharacter = (value: string): boolean => {
  const stripped = stripWrappedContent(value);
  if (/[\t\n\r]/.test(stripped)) return true;
  return stripped.includes("\\");
};

export const safeString = z
  .string()
  .refine((v) => !containsForbiddenCharacter(v), {
    message: "Must not contain tab, backslash, or newline characters",
  });