feat(users): user service

service/user.go

@@ -0,0 +1,84 @@
+package service
+
+import (
+	"errors"
+	"time"
+
+	"forge.capytal.company/capytalcode/project-comicverse/model"
+	"forge.capytal.company/capytalcode/project-comicverse/repository"
+	"forge.capytal.company/loreddev/x/tinyssert"
+	"github.com/golang-jwt/jwt/v4"
+	"github.com/google/uuid"
+	"golang.org/x/crypto/bcrypt"
+)
+
+type UserService struct {
+	assert tinyssert.Assertions
+	repo   *repository.UserRepository
+}
+
+func NewUserService(repo *repository.UserRepository, assert tinyssert.Assertions) *UserService {
+	assert.NotNil(repo)
+
+	return &UserService{repo: repo, assert: assert}
+}
+
+func (s *UserService) Register(username, password string) (model.User, error) {
+	if _, err := s.repo.GetByUsername(username); err == nil {
+		return model.User{}, ErrAlreadyExists
+	}
+
+	hash, err := bcrypt.GenerateFromPassword([]byte(password), bcrypt.DefaultCost)
+	if err != nil {
+		return model.User{}, err
+	}
+
+	u := model.User{
+		Username:    username,
+		Password:    hash,
+		DateCreated: time.Now(),
+		DateUpdated: time.Now(),
+	}
+
+	u, err = s.repo.Create(u)
+	if err != nil {
+		return model.User{}, errors.Join(errors.New("failed to create user model"), err)
+	}
+
+	return u, nil
+}
+
+func (s *UserService) Login(username, password string) (token *jwt.Token, user model.User, err error) {
+	user, err = s.repo.GetByUsername(username)
+	if err != nil {
+		return nil, model.User{}, err
+	}
+
+	err = bcrypt.CompareHashAndPassword(user.Password, []byte(password))
+	if err != nil {
+		return nil, model.User{}, err
+	}
+
+	t := time.Now()
+	jti, err := uuid.NewV7()
+	if err != nil {
+		return nil, model.User{}, err
+	}
+
+	token = jwt.NewWithClaims(jwt.SigningMethodES256, jwt.RegisteredClaims{
+		Issuer:    "comicverse",
+		Subject:   username,
+		IssuedAt:  &jwt.NewNumericDate(t),
+		NotBefore: &jwt.NewNumericDate(t),
+		ID:        jti.String(),
+	})
+
+	return token, user, nil
+}
+
+var (
+	ErrAlreadyExists     = errors.New("model already exists")
+	ErrNotFound          = repository.ErrNotFound
+	ErrPasswordTooLong   = bcrypt.ErrPasswordTooLong
+	ErrIncorrectPassword = bcrypt.ErrMismatchedHashAndPassword
+)