package jwt

import (
	"maps"
	"time"

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

type Service struct {
	signer Signer
}

func NewService(signer Signer) *Service {
	return &Service{
		signer: signer,
	}
}

// Generate creates a new JWT token for a given user ID and
// returns the token string along with its JTI(JWT IDentifier).
func (s *Service) Generate(ttl time.Duration, extraClaims jwt.MapClaims) (string, string, error) {
	jti := uuid.NewString()

	claims := jwt.MapClaims{
		"jti": jti,
		"exp": time.Now().Add(ttl).Unix(),
		"iat": time.Now().Unix(),
	}
	maps.Copy(claims, extraClaims)

	token, err := s.signer.Sign(claims)
	return token, jti, err
}

// Validate verifies the JWT token and extracts the claims and JTI(JWT IDentifier).
func (s *Service) Validate(token string) (jwt.MapClaims, string, error) {
	claims, err := s.signer.Verify(token)
	if err != nil {
		return nil, "", err
	}

	jti := claims.(jwt.MapClaims)["jti"].(string)

	return claims.(jwt.MapClaims), jti, nil
}