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")
+
+}