package security

import (
	"errors"
	"github.com/golang-jwt/jwt"
	"os"
	"time"
)

type PresignToken struct {
	Path string
}

func CreateToken(tokenInfo PresignToken, duration time.Duration) (string, error) {
	// jwt token
	atClaims := jwt.MapClaims{}
	atClaims["authorized"] = true
	// user info
	atClaims["path"] = tokenInfo.Path
	// expiration
	atClaims["exp"] = time.Now().Add(duration).Unix()
	at := jwt.NewWithClaims(jwt.SigningMethodHS256, atClaims)

	secret := getSecret()
	return at.SignedString([]byte(secret))
}

func ParseToken(token string) (PresignToken, error) {
	secret := getSecret()
	parsedToken, err := jwt.Parse(token, func(t *jwt.Token) (interface{}, error) {
		return []byte(secret), nil
	})
	if err != nil {
		return PresignToken{}, err
	}
	claims, ok := parsedToken.Claims.(jwt.MapClaims)
	if ok {
		return PresignToken{
			Path: claims["path"].(string),
		}, nil
	} else {
		return PresignToken{}, errors.New("failed parsing token")
	}
}

func getSecret() string {
	secret, exists := os.LookupEnv("JWT_SECRET")
	if !exists {
		panic("env variable JWT_SECRET not set")
	}
	return secret
}