package jwt

import (
	"time"

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

type Claims struct {
	UserId   int64  `json:"user_id"`
	Username string `json:"username"`
	jwt.RegisteredClaims
}

func GenerateToken(userId int64, username string, secret string, expires time.Duration) (string, error) {
	now := time.Now()
	claims := Claims{
		UserId:   userId,
		Username: username,
		RegisteredClaims: jwt.RegisteredClaims{
			ExpiresAt: jwt.NewNumericDate(now.Add(expires)),
			IssuedAt:  jwt.NewNumericDate(now),
			NotBefore: jwt.NewNumericDate(now),
		},
	}

	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
	return token.SignedString([]byte(secret))
}

func ParseToken(tokenString string, secret string) (*Claims, error) {
	token, err := jwt.ParseWithClaims(tokenString, &Claims{}, func(token *jwt.Token) (interface{}, error) {
		return []byte(secret), nil
	})

	if err != nil {
		return nil, err
	}

	if claims, ok := token.Claims.(*Claims); ok && token.Valid {
		return claims, nil
	}

	return nil, jwt.ErrInvalidKey
}