validate CPF DataWeave / Mulesoft

isCpf

%dw 2.0
output application/json
import * from dw::core::Strings

var cpf = leftPad(payload.cpf, 11, "0")
var size = sizeOf(cpf)
var chars = splitBy(cpf, "") [0 to 8]
var verify = splitBy(cpf, "") [9 to 10]

fun sumcpf1(cpf) =
    chars[0] * 10 + 
    chars[1] * 9 + 
    chars[2] * 8 +
    chars[3] * 7 +
    chars[4] * 6 +
    chars[5] * 5 +
    chars[6] * 4 +
    chars[7] * 3 +
    chars[8] * 2 

fun firstdigit(cpf) = 
    if(11- mod(sumcpf1(cpf), 11)>10)
        0
    else 
        11 - mod(sumcpf1(cpf), 11)

fun sumcpf2(cpf) =
    chars[0] * 11 + 
    chars[1] * 10 + 
    chars[2] * 9 +
    chars[3] * 8 +
    chars[4] * 7 +
    chars[5] * 6 +
    chars[6] * 5 +
    chars[7] * 4 +
    chars[8] * 3 +
    verify[0] * 2 

fun seconddigit(cpf) = 
    if(11- mod(sumcpf2(cpf), 11)>10)
        0
    else 
        11 - mod(sumcpf2(cpf), 11)

fun isCpf(cpf) =
    (firstdigit(cpf) ++ seconddigit(cpf)) == joinBy(verify,"")
    
---
{
    verify: joinBy(verify,""),
    correct: firstdigit(payload.cpf) ++ seconddigit(payload.cpf),
    isvalid: isCpf(payload.cpf)
}