first

backend/internal/modules/users/repository.go

@@ -0,0 +1,98 @@
+package users
+
+import (
+	"context"
+	"errors"
+
+	"github.com/google/uuid"
+	"github.com/jackc/pgx/v5/pgconn"
+	"gorm.io/gorm"
+)
+
+var ErrNotFound = errors.New("user not found")
+var ErrEmailTaken = errors.New("email already in use")
+
+type Repository interface {
+	Create(ctx context.Context, user *User) error
+	FindByEmail(ctx context.Context, email string) (*User, error)
+	FindByID(ctx context.Context, id uuid.UUID) (*User, error)
+	List(ctx context.Context) ([]*User, error)
+	Update(ctx context.Context, user *User) error
+	Delete(ctx context.Context, id uuid.UUID) error
+}
+
+type gormRepository struct {
+	db *gorm.DB
+}
+
+func NewRepository(db *gorm.DB) Repository {
+	return &gormRepository{db: db}
+}
+
+func (r *gormRepository) Create(ctx context.Context, user *User) error {
+	if err := r.db.WithContext(ctx).Create(user).Error; err != nil {
+		if isUniqueViolation(err) {
+			return ErrEmailTaken
+		}
+		return err
+	}
+	return nil
+}
+
+func (r *gormRepository) FindByEmail(ctx context.Context, email string) (*User, error) {
+	var user User
+	err := r.db.WithContext(ctx).Where("email = ?", email).First(&user).Error
+	if errors.Is(err, gorm.ErrRecordNotFound) {
+		return nil, ErrNotFound
+	}
+	if err != nil {
+		return nil, err
+	}
+	return &user, nil
+}
+
+func (r *gormRepository) FindByID(ctx context.Context, id uuid.UUID) (*User, error) {
+	var user User
+	err := r.db.WithContext(ctx).Where("id = ?", id).First(&user).Error
+	if errors.Is(err, gorm.ErrRecordNotFound) {
+		return nil, ErrNotFound
+	}
+	if err != nil {
+		return nil, err
+	}
+	return &user, nil
+}
+
+func (r *gormRepository) List(ctx context.Context) ([]*User, error) {
+	var list []*User
+	if err := r.db.WithContext(ctx).Order("created_at asc").Find(&list).Error; err != nil {
+		return nil, err
+	}
+	return list, nil
+}
+
+func (r *gormRepository) Update(ctx context.Context, user *User) error {
+	err := r.db.WithContext(ctx).Save(user).Error
+	if isUniqueViolation(err) {
+		return ErrEmailTaken
+	}
+	return err
+}
+
+func (r *gormRepository) Delete(ctx context.Context, id uuid.UUID) error {
+	res := r.db.WithContext(ctx).Delete(&User{}, "id = ?", id)
+	if res.Error != nil {
+		return res.Error
+	}
+	if res.RowsAffected == 0 {
+		return ErrNotFound
+	}
+	return nil
+}
+
+// isUniqueViolation reports whether err is a Postgres unique-constraint
+// violation (SQLSTATE 23505), e.g. a duplicate email.
+func isUniqueViolation(err error) bool {
+	var pgErr *pgconn.PgError
+	return errors.As(err, &pgErr) && pgErr.Code == "23505"
+}