package jwt

import (
	"mangezmieux-backend/internal/responses"
	"time"

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

type Service struct {
	SecretKey string
}

func NewService() *Service {
	return &Service{SecretKey: "hard-coded-temp"}
}

type Claims struct {
	ID string `json:"username"`
	jwtLib.RegisteredClaims
}

func (s *Service) ValidateToken(token string) (*Claims, error) {
	claims := &Claims{}
	tkn, err := jwtLib.ParseWithClaims(token, claims, func(token *jwtLib.Token) (any, error) {
		return []byte(s.SecretKey), nil
	})
	if err != nil {
		return nil, err
	}

	if !tkn.Valid {
		return nil, err
	}

	return claims, nil
}

func (s *Service) GenerateJWTToken(userId string) (string, error) {
	expirationTime := time.Now().Add(10 * time.Minute)

	claims := &Claims{
		ID: userId,
		RegisteredClaims: jwtLib.RegisteredClaims{
			// In JWT, the expiry time is expressed as unix milliseconds
			ExpiresAt: jwtLib.NewNumericDate(expirationTime),
		},
	}
	token := jwtLib.NewWithClaims(jwtLib.SigningMethodHS256, claims)
	// Create the JWT string
	tokenString, err := token.SignedString([]byte(s.SecretKey))
	if err != nil {
		return "", &responses.ErrInternalServer
	}
	return tokenString, nil
}

func (s *Service) Refresh(oldToken string) (string, error) {
	claims := &Claims{}
	tkn, err := jwtLib.ParseWithClaims(oldToken, claims, func(token *jwtLib.Token) (any, error) {
		return []byte(s.SecretKey), nil
	})
	if err != nil {
		return "", err
	}

	if !tkn.Valid {
		return "", err
	}

	// Now, create a new token for the current use, with a renewed expiration time
	expirationTime := time.Now().Add(10 * time.Minute)
	claims.ExpiresAt = jwtLib.NewNumericDate(expirationTime)
	token := jwtLib.NewWithClaims(jwtLib.SigningMethodHS256, claims)
	tokenString, err := token.SignedString([]byte(s.SecretKey))
	return tokenString, nil

}