package utils

import (
	"fmt"
	"time"

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

var jwtKey []byte

type MyClaims struct {
	Username string `json:"username"`
	jwt.RegisteredClaims
}

func SetSecret(secret []byte) {
	jwtKey = []byte(secret)
}

func GenerateToken(username string) (string, error) {
	expirationTime := time.Now().Add(3 * 24 * time.Hour)

	claims := &MyClaims{
		Username: username,
		RegisteredClaims: jwt.RegisteredClaims{
			ExpiresAt: jwt.NewNumericDate(expirationTime),
			IssuedAt:  jwt.NewNumericDate(time.Now()),
			NotBefore: jwt.NewNumericDate(time.Now()),
		},
	}

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

	tokenString, err := token.SignedString(jwtKey)
	if err != nil {
		return "", err
	}

	return tokenString, nil
}

func VerifyToken(tokenString string) (*MyClaims, error) {
	claims := &MyClaims{}

	token, err := jwt.ParseWithClaims(tokenString, claims, func(token *jwt.Token) (interface{}, error) {
		return jwtKey, nil
	})

	if err != nil {
		return nil, err
	}

	if !token.Valid {
		return nil, fmt.Errorf("invalid token")
	}

	return claims, nil
}