formbricks-formbricks/packages/lib/utils/singleUseSurveys.ts

import cuid2 from "@paralleldrive/cuid2";
import { decryptAES128, symmetricDecrypt, symmetricEncrypt } from "../../lib/crypto";
import { env } from "../../lib/env";

// generate encrypted single use id for the survey
export const generateSurveySingleUseId = (isEncrypted: boolean): string => {
  const cuid = cuid2.createId();
  if (!isEncrypted) {
    return cuid;
  }

  const encryptedCuid = symmetricEncrypt(cuid, env.ENCRYPTION_KEY);
  return encryptedCuid;
};

export const generateSurveySingleUseIds = (count: number, isEncrypted: boolean): string[] => {
  const singleUseIds: string[] = [];

  for (let i = 0; i < count; i++) {
    singleUseIds.push(generateSurveySingleUseId(isEncrypted));
  }

  return singleUseIds;
};

// validate the survey single use id
export const validateSurveySingleUseId = (surveySingleUseId: string): string | undefined => {
  try {
    let decryptedCuid: string | null = null;

    if (surveySingleUseId.length === 64) {
      if (!env.FORMBRICKS_ENCRYPTION_KEY) {
        throw new Error("FORMBRICKS_ENCRYPTION_KEY is not defined");
      }

      decryptedCuid = decryptAES128(env.FORMBRICKS_ENCRYPTION_KEY!, surveySingleUseId);
    } else {
      decryptedCuid = symmetricDecrypt(surveySingleUseId, env.ENCRYPTION_KEY);
    }

    if (cuid2.isCuid(decryptedCuid)) {
      return decryptedCuid;
    } else {
      return undefined;
    }
  } catch (error) {
    return undefined;
  }
};