package auth

import (
	"fmt"
	"os"
	"time"

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

var secretKey = os.Getenv("JWT_SECRET_KEY")

type UserClaims struct {
	jwt.RegisteredClaims
	UserID int64
}

func GenerateUserToken(userId int64, expiryTime time.Time) (string, error) {
	now := time.Now()
	claims := UserClaims{
		UserID: userId,
		RegisteredClaims: jwt.RegisteredClaims{
			IssuedAt:  jwt.NewNumericDate(now),
			ExpiresAt: jwt.NewNumericDate(expiryTime),
		},
	}

	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)

	return token.SignedString([]byte(secretKey))
}

func ValidateUserToken(token string) (int64, error) {
	claims := &UserClaims{}

	parsed, err := jwt.ParseWithClaims(token, claims, func(t *jwt.Token) (any, error) {
		return []byte(secretKey), nil
	})
	if err != nil {
		return -1, fmt.Errorf("failed to parse token: %v", err)
	}

	if !parsed.Valid {
		return -1, fmt.Errorf("invalid token")
	}

	return claims.UserID, nil
}