add

trading_assistant_api/services/user/internal/service/user_service.go

@@ -0,0 +1,92 @@
+package service
+
+import (
+	"database/sql"
+	"errors"
+
+	"github.com/jackc/pgconn"
+	"golang.org/x/crypto/bcrypt"
+	"user/internal/repository"
+)
+
+var (
+	ErrInvalidInput = errors.New("invalid_input")
+	ErrAccountExists = errors.New("account_exists")
+	ErrUnauthorized = errors.New("unauthorized")
+)
+
+type Service struct {
+	Repo *repository.Repo
+}
+
+func New(repo *repository.Repo) *Service {
+	return &Service{Repo: repo}
+}
+
+func (s *Service) Register(account, password string) (string, error) {
+	if !validAccount(account) || !validPassword(password) {
+		return "", ErrInvalidInput
+	}
+	hashed, err := bcrypt.GenerateFromPassword([]byte(password), 12)
+	if err != nil {
+		return "", err
+	}
+	tx, err := s.Repo.DB.Begin()
+	if err != nil {
+		return "", err
+	}
+	defer func() { _ = tx.Rollback() }()
+	userID, err := s.Repo.CreateUser(tx)
+	if err != nil {
+		return "", err
+	}
+	if err := s.Repo.CreateLoginAccount(tx, userID, account); err != nil {
+		if isUniqueViolation(err) {
+			return "", ErrAccountExists
+		}
+		return "", err
+	}
+	if err := s.Repo.CreateLoginPassword(tx, userID, string(hashed)); err != nil {
+		return "", err
+	}
+	if err := tx.Commit(); err != nil {
+		return "", err
+	}
+	return userID, nil
+}
+
+func (s *Service) Login(account, password string) (string, error) {
+	if !validAccount(account) || !validPassword(password) {
+		return "", ErrInvalidInput
+	}
+	userID, err := s.Repo.GetUserIDByAccount(account)
+	if err != nil {
+		return "", ErrUnauthorized
+	}
+	hashed, err := s.Repo.GetHashedPassword(userID)
+	if err != nil {
+		return "", ErrUnauthorized
+	}
+	if bcrypt.CompareHashAndPassword([]byte(hashed), []byte(password)) != nil {
+		return "", ErrUnauthorized
+	}
+	return userID, nil
+}
+
+func validAccount(a string) bool {
+	n := len(a)
+	return n >= 3 && n <= 100
+}
+
+func validPassword(p string) bool {
+	n := len(p)
+	return n >= 8 && n <= 128
+}
+
+func isUniqueViolation(err error) bool {
+	var pe *pgconn.PgError
+	if errors.As(err, &pe) {
+		return pe.Code == "23505"
+	}
+	return false
+}