Merge pull request #21 from brazzcore/feature/22-generate-a-valid-cpf

[feature/22] :: generate a valid cpf

Author: wellfernandes

examples/mock_example.go

@@ -33,8 +33,8 @@ func GenerateMockExample() {
 	fmt.Println(constants.HeaderMain)
 	fmt.Println(constants.SubHeader)
 
-	fmt.Printf("Person: %s %s, %s, %d years old\n",
-		person_mock.FirstNameMale, person_mock.LastName, person_mock.Gender, person_mock.Age)
+	fmt.Printf("Person: %s %s, %s, %d years old, CPF: %s\n",
+		person_mock.FirstNameMale, person_mock.LastName, person_mock.Gender, person_mock.Age, person_mock.CPF)
 	fmt.Printf("Address: %s, %d - %s, %s (%s) - %s\n",
 		address_mock.Street, address_mock.Number, address_mock.City, address_mock.State, address_mock.UF, address_mock.ZIP)
 	fmt.Printf("Phone: (%s) %s\n", phone_mock.AreaCode, phone_mock.Number)

pkg/mocai/entities/cpf/errors.go

@@ -0,0 +1,7 @@
+package cpf
+
+import "errors"
+
+var (
+	ErrInvalidCPF = errors.New("invalid CPF")
+)

pkg/mocai/entities/cpf/generator.go

@@ -0,0 +1,58 @@
+package cpf
+
+import (
+	"errors"
+	"fmt"
+	"math/rand"
+	"strings"
+	"time"
+)
+
+// GenerateCPF generates a valid CPF number.
+// If formatted is true, the CPF will be returned in the format xxx.xxx.xxx-xx.
+// If formatted is false, the CPF will be returned as a plain string of 11 digits.
+func GenerateCPF(formatted bool) (string, error) {
+	// Create a local random generator with a unique seed
+	src := rand.NewSource(time.Now().UnixNano())
+	r := rand.New(src)
+
+	// Generate the first 9 digits
+	digits := make([]int, 9)
+	for i := range digits {
+		digits[i] = r.Intn(10)
+	}
+
+	// Calculate the first check digit
+	digits = append(digits, calculateCheckDigit(digits, 10))
+
+	// Calculate the second check digit
+	digits = append(digits, calculateCheckDigit(digits, 11))
+
+	// Convert the digits to a string
+	cpf := strings.Trim(strings.Join(strings.Fields(fmt.Sprint(digits)), ""), "[]")
+
+	// Format the CPF if requested
+	if formatted {
+		if len(cpf) != 11 {
+			return "", errors.New(ErrInvalidCPF.Error())
+		}
+		return cpf[:3] + "." + cpf[3:6] + "." + cpf[6:9] + "-" + cpf[9:], nil
+	}
+
+	return cpf, nil
+}
+
+// calculateCheckDigit calculates the check digit for a CPF.
+func calculateCheckDigit(digits []int, weight int) int {
+	sum := 0
+	for _, digit := range digits {
+		sum += digit * weight
+		weight--
+	}
+
+	remainder := sum % 11
+	if remainder < 2 {
+		return 0
+	}
+	return 11 - remainder
+}

pkg/mocai/entities/cpf/validator.go

@@ -0,0 +1,51 @@
+package cpf
+
+import (
+	"strconv"
+	"strings"
+)
+
+// ValidateCPF checks if a CPF is valid.
+// It accepts both formatted (xxx.xxx.xxx-xx) and unformatted (xxxxxxxxxxx) CPFs.
+func ValidateCPF(cpf string) bool {
+	// Remove formatting (dots and dashes)
+	cpf = strings.ReplaceAll(cpf, ".", "")
+	cpf = strings.ReplaceAll(cpf, "-", "")
+
+	// Check if the CPF has 11 digits
+	if len(cpf) != 11 {
+		return false
+	}
+
+	// Convert the CPF string to a slice of integers
+	digits := make([]int, 11)
+	for i, char := range cpf {
+		digit, err := strconv.Atoi(string(char))
+		if err != nil {
+			return false
+		}
+		digits[i] = digit
+	}
+
+	// Check if all digits are the same (invalid CPF)
+	allSame := true
+	for i := 1; i < len(digits); i++ {
+		if digits[i] != digits[0] {
+			allSame = false
+			break
+		}
+	}
+	if allSame {
+		return false
+	}
+
+	// Calculate the first check digit
+	firstCheckDigit := calculateCheckDigit(digits[:9], 10)
+	if firstCheckDigit != digits[9] {
+		return false
+	}
+
+	// Calculate the second check digit
+	secondCheckDigit := calculateCheckDigit(digits[:10], 11)
+	return secondCheckDigit == digits[10]
+}

pkg/mocai/entities/person/generator.go

@@ -6,6 +6,7 @@ import (
 	"math/rand"
 	"strings"
 
+	"github.com/brazzcore/mocai/pkg/mocai/entities/cpf"
 	"github.com/brazzcore/mocai/pkg/mocai/entities/gender"
 	"github.com/brazzcore/mocai/pkg/mocai/translations"
 )
@@ -17,6 +18,7 @@ type Person struct {
 	LastName        string
 	Gender          gender.Gender
 	Age             int
+	CPF             string
 }
 
 // GeneratePerson generates a mock person with random data.
@@ -49,6 +51,12 @@ func GeneratePerson() (*Person, error) {
 		return nil, err
 	}
 
+	// Generate a random CPF without a mask
+	cpf, err := cpf.GenerateCPF(false)
+	if err != nil {
+		return nil, err
+	}
+
 	// Validate required fields
 	if firstNameMale == "" || firstNameFemale == "" || lastName == "" {
 		return nil, fmt.Errorf("%s: missing required data (firstNameMale: %s, firstNameFemale: %s, lastName: %s)",
@@ -61,6 +69,7 @@ func GeneratePerson() (*Person, error) {
 		LastName:        lastName,
 		Gender:          gender,
 		Age:             rand.Intn(80) + 18,
+		CPF:             cpf,
 	}
 
 	return createdPerson, nil