validatorChileanRut.swift

import Foundation

//////
//
// funcion para validar DV en rut chileno, 
// Swift 4 Xcode 9.x
//
//
// Modo de uso:

do{
      let validator = try FormValidator.validateRut("16242343-5") //cambiar por string de rut a validar
   
    }catch RutError.InvalidRut(let message) {
      
      showMessage("Error", message: message, action: nil)
    }catch{
      DDLogError("an error ocurred during rut validation")
}

//

enum RutError: ErrorType{
  
  case InvalidRut(message : String)
  
}
class FormValidator: NSObject {
  
static func validadorRut(input: String!)  throws -> String?{
        var rut = input.replacingOccurrences(of: ".", with: "", options: NSString.CompareOptions.literal, range : nil)
        rut = rut.replacingOccurrences(of: "-", with: "", options: NSString.CompareOptions.literal, range : nil)
        rut = rut.uppercased()
        
        if (rut.count < 8 || rut.count > 10){
            throw rutErrors.invalidRut(message: "Largo de RUT no válido")
        }
        
        let rutRegex = "^(\\d{1,3}(\\.?\\d{3}){2})\\-?([\\dkK])$"
        
        let rutTest = NSPredicate(format: "SELF MATCHES %@", rutRegex)
        
        if (!rutTest.evaluate(with: rut)) {
            throw rutErrors.invalidRut(message: "RUT con fomato no válido")
        }
        
        let runTovalidate = getRutDv(value: input)
        
        let rutNumber = runTovalidate.0
        let rutDV = runTovalidate.1
        
        let calculatedDV = validateDV(rut: rutNumber)
        print(runTovalidate)
        print(calculatedDV!)
        if (rutDV != calculatedDV){
            throw rutErrors.invalidRut(message: "Digito verificador no válido")
        }
        
        return rut
    }
    
    static func getRutDv(value: String) -> (String, String){
        if (value.isEmpty || value.count < 2){
            return ("", "")
        }
        
        var rut = value.replacingOccurrences(of: ".", with: "", options: NSString.CompareOptions.literal, range: nil)
        rut = rut.replacingOccurrences(of: "-", with: "", options: NSString.CompareOptions.literal, range: nil)
        
        let dv: String = String(rut.last!)
        let run: String = String(rut.dropLast())
        
        return (run, dv)
    }
    
    static func validateDV(rut: String) -> String?{
        var acumulado : Int = 0
        var ti : Int = 2
        print(rut.count)
        for index in stride(from: rut.count-1, through: 0, by: -1) {
            let n = Array(rut)[index]
            let nl = String(n)
            guard let vl = Int(nl) else {
                return ""
            }
            
            
            acumulado += vl * ti
            
            if (ti == 7) {
                ti = 1
            }
            ti += 1
        }

        let resto : Int = acumulado % 11
        let numericDigit : Int = 11 - resto
        var digito : String = ""

        
        if (numericDigit <= 9){
            digito = String(numericDigit);
        }else if (numericDigit == 10){
            digito = "K"
        }else{
            digito = "0"
        }
        
        return digito
    }
}