validator.go

package main

import (
	"errors"
	"fmt"
	"regexp"
)

type ValidatorFunc func(value string) (bool, error)

type ValidationRules struct {
	AllowList []ValidatorFunc
	DenyList  []ValidatorFunc
}

func (vr *ValidationRules) Validate(value string) (bool, error) {
	for _, deny := range vr.DenyList {
		if valid, err := deny(value); !valid {
			return false, err
		}
	}
	for _, allow := range vr.AllowList {
		if valid, _ := allow(value); valid {
			return true, nil
		}
	}
	return false, errors.New("valor não permitido")
}

func validateIDFormat(value string) (bool, error) {
	match, _ := regexp.MatchString(`^\d{1,10}$`, value)
	if !match {
		return false, errors.New("ID inválido: deve conter apenas números e ter no máximo 10 dígitos")
	}
	return true, nil
}

func denySpecialChars(value string) (bool, error) {
	match, _ := regexp.MatchString(`[^a-zA-Z0-9]`, value)
	if match {
		return false, errors.New("valor contém caracteres especiais não permitidos")
	}
	return true, nil
}

// Validadores para AmountMoney
func validateAmountFormat(value string) (bool, error) {
	match, _ := regexp.MatchString(`^\d+(\.\d{1,2})?$`, value)
	if !match {
		return false, errors.New("quantia inválida: deve ser um número com até duas casas decimais")
	}
	return true, nil
}

func denyNegativeAmount(value string) (bool, error) {
	if value[0] == '-' {
		return false, errors.New("quantia não pode ser negativa")
	}
	return true, nil
}

func main() {
	idRules := ValidationRules{
		AllowList: []ValidatorFunc{validateIDFormat},
		DenyList:  []ValidatorFunc{denySpecialChars},
	}
	
	amountRules := ValidationRules{
		AllowList: []ValidatorFunc{validateAmountFormat},
		DenyList:  []ValidatorFunc{denyNegativeAmount},
	}

	tests := map[string]string{
		"Valid ID":        "123456",
		"Invalid ID":      "123@456",
		"Valid Amount":    "100.50",
		"Invalid Amount":  "-50.00",
	}

	for testName, value := range tests {
		var rules *ValidationRules
		if testName == "Valid ID" || testName == "Invalid ID" {
			rules = &idRules
		} else {
			rules = &amountRules
		}
		valid, err := rules.Validate(value)
		fmt.Printf("%s (%s): Valid=%v, Error=%v\n", testName, value, valid, err)
	}
}