package auth

import (
	"time"

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

var signingkey []byte

type JWTClaims struct {
	User string `json:"user"`
	jwt.RegisteredClaims
}

func SetSigningKey(key string) {
	signingkey = []byte(key)
}

func NewJWT(user string) (string, error) {
	claims := JWTClaims{
		user,
		jwt.RegisteredClaims{
			ExpiresAt: jwt.NewNumericDate(time.Now().Add(15 * time.Minute)), // Expires in 24 hours
			IssuedAt:  jwt.NewNumericDate(time.Now()),
			Issuer:    "outfit-voting-abi26",
		},
	}
	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)

	return token.SignedString(signingkey)
}

func ValidateJWT(token string) (string, error) {
	claims := &JWTClaims{}
	parsed, err := jwt.ParseWithClaims(token, claims, func(t *jwt.Token) (any, error) {
		if _, ok := t.Method.(*jwt.SigningMethodHMAC); !ok {
			return nil, jwt.ErrSignatureInvalid
		}
		return signingkey, nil
	})

	if err != nil {
		return "", err
	}

	claims, ok := parsed.Claims.(*JWTClaims)

	if !ok {
		return "", jwt.ErrTokenInvalidClaims
	}

	return claims.User, nil
}