start implementing auth

services/user.go

@@ -0,0 +1,66 @@
+package services
+
+import (
+	"database/sql"
+	"go-weather/models"
+	"time"
+
+	"golang.org/x/crypto/bcrypt"
+)
+
+type UserService struct {
+	db *sql.DB
+}
+
+func NewUserService(db *sql.DB) *UserService {
+	return &UserService{db: db}
+}
+
+func (s *UserService) CreateUser(email string, password string) (*models.User, error) {
+	hashedPassword, err := bcrypt.GenerateFromPassword([]byte(password), bcrypt.DefaultCost)
+
+	if err != nil {
+		return nil, err
+	}
+
+	var user models.User
+	err = s.db.QueryRow(
+		`INSERT INTO users (email, password_hash, created_at)
+		 VALUES ($1, $2, $3)
+		 RETURNING id, email, created_at`,
+		email, string(hashedPassword), time.Now(),
+	).Scan(&user.ID, &user.Email, &user.CreatedAt)
+
+	if err != nil {
+		return nil, err
+	}
+
+	return &user, nil
+
+}
+
+func (s *UserService) GetUserByEmail(email string) (*models.User, error) {
+
+	var user models.User
+	err := s.db.QueryRow(
+		`SELECT id, email, password_hash, created_at
+		 FROM users
+		 WHERE email = $1`, email,
+	).Scan(&user.ID, &user.Email, &user.PasswordHash, &user.CreatedAt)
+
+	if err != nil {
+		return nil, nil
+	}
+
+	return &user, nil
+}
+
+func (s *UserService) EmailExists(email string) (bool, error) {
+	var exists bool
+	err := s.db.QueryRow(`SELECT EXISTS(SELECT 1 FROM users WHERE email = $1)`, email).Scan(&exists)
+	return exists, err
+}
+func (s *UserService) ValidatePassword(user *models.User, password string) bool {
+	err := bcrypt.CompareHashAndPassword([]byte(user.PasswordHash), []byte(password))
+	return err == nil
+}