start implementing auth

services/auth.go

@@ -0,0 +1,57 @@
+package services
+
+import (
+	"errors"
+	"time"
+
+	"github.com/golang-jwt/jwt/v5"
+)
+
+type Claims struct {
+	UserID int    `json:"user_id"`
+	Email  string `json:"email"`
+	jwt.RegisteredClaims
+}
+
+type AuthService struct {
+	secretKey []byte
+}
+
+func NewAuthService(secret string) *AuthService {
+	return &AuthService{secretKey: []byte(secret)}
+}
+
+func (s *AuthService) GenerateToken(userID int, email string) (string, error) {
+	claims := Claims{
+		UserID: userID,
+		Email:  email,
+		RegisteredClaims: jwt.RegisteredClaims{
+			ExpiresAt: jwt.NewNumericDate(time.Now().Add(24 * time.Hour)),
+			IssuedAt:  jwt.NewNumericDate(time.Now()),
+		},
+	}
+
+	token := jwt.NewWithClaims(jwt.SigningMethodES256, claims)
+	return token.SignedString(s.secretKey)
+}
+
+func (s *AuthService) ValidateToken(tokenString string) (*Claims, error) {
+	token, err := jwt.ParseWithClaims(tokenString, &Claims, func(token *jwt.Token) (interface{}, error) {
+		if _, ok := token.Method.(*jwt.SigningMethodHMAC); !ok {
+			return nil, errors.New("unexpected signing method")
+		}
+		return s.secretKey, nil
+
+	})
+
+	if err != nil {
+		return nil, err
+	}
+
+	if claims, ok := token.Claims.(*Claims); ok && token.Valid {
+		return claims, nil
+	}
+
+	return nil, errors.New("invalid token")
+
+}

services/database.go

@@ -5,7 +5,6 @@ import (
 	"fmt"
 	_ "github.com/lib/pq"
 	"go-weather/models"
-	"log"
 	"time"
 )
 

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
+}