package utils

import (
	"errors"
	"time"

	"github.com/golang-jwt/jwt/v5"
)

type Claims struct {
	UserName string `json:"user_name"`
	UserMail string `json:"user_mail"`
	jwt.RegisteredClaims
}

func GenerateToken(secret, issuer, userID, userName, userMail string, ttl time.Duration) (string, error) {
	now := time.Now()
	claims := Claims{
		UserName: userName,
		UserMail: userMail,
		RegisteredClaims: jwt.RegisteredClaims{
			Subject:   userID,
			Issuer:    issuer,
			IssuedAt:  jwt.NewNumericDate(now),
			ExpiresAt: jwt.NewNumericDate(now.Add(ttl)),
		},
	}
	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
	return token.SignedString([]byte(secret))
}

func ValidateToken(secret string, tokenString string) (*Claims, error) {
	token, err := jwt.ParseWithClaims(tokenString, &Claims{}, func(t *jwt.Token) (interface{}, error) {
		if t.Method != jwt.SigningMethodHS256 {
			return nil, errors.New("unexpected signing method")
		}
		return []byte(secret), nil
	})
	if err != nil {
		return nil, err
	}

	claims, ok := token.Claims.(*Claims)
	if !ok || !token.Valid {
		return nil, errors.New("invalid token")
	}
	return claims, nil
}