import { z } from "zod";
// Input normalization functions
const normalizeCnpj = (input: string) => input.replace(/\D/g, "");
const normalizeCep = (input: string) => input.replace(/\D/g, "");
/**
* Validates CNPJ checksum using mod-11 algorithm
* @param cnpj - 14-digit CNPJ string (digits only)
* @returns true if checksum is valid, false otherwise
*/
function validateCnpjChecksum(cnpj: string): boolean {
// Must be exactly 14 digits
if (cnpj.length !== 14 || !/^\d{14}$/.test(cnpj)) {
return false;
}
// Reject CNPJs with all identical digits (e.g., "11111111111111")
if (/^(\d)\1{13}$/.test(cnpj)) {
return false;
}
// Calculate first check digit
let sum = 0;
let multiplier = 5;
for (let i = 0; i < 12; i++) {
sum += parseInt(cnpj[i]) * multiplier;
multiplier = multiplier === 2 ? 9 : multiplier - 1;
}
const remainder1 = sum % 11;
const digit1 = remainder1 < 2 ? 0 : 11 - remainder1;
// Calculate second check digit
sum = 0;
multiplier = 6;
for (let i = 0; i < 13; i++) {
sum += parseInt(cnpj[i]) * multiplier;
multiplier = multiplier === 2 ? 9 : multiplier - 1;
}
const remainder2 = sum % 11;
const digit2 = remainder2 < 2 ? 0 : 11 - remainder2;
// Verify both check digits
return parseInt(cnpj[12]) === digit1 && parseInt(cnpj[13]) === digit2;
}
// Validation schemas
export const CnpjSchema = z.object({
cnpj: z
.string()
.describe("CNPJ number to lookup (with or without formatting)")
.transform(normalizeCnpj)
.refine((cnpj) => cnpj.length === 14 && /^\d{14}$/.test(cnpj), {
message: "CNPJ must be exactly 14 digits",
})
.refine(validateCnpjChecksum, {
message: "Invalid CNPJ: checksum verification failed",
}),
});
export const CepSchema = z.object({
cep: z
.string()
.describe("CEP postal code to lookup (with or without formatting)")
.transform(normalizeCep)
.refine((cep) => cep.length === 8 && /^\d{8}$/.test(cep), {
message: "CEP must be exactly 8 digits",
}),
});
// Export normalization and validation functions for reuse
export { normalizeCnpj, normalizeCep, validateCnpjChecksum };
