package jwt

import (
	"errors"
	"time"

	"github.com/dgrijalva/jwt-go"
)

var JwtKey = []byte("bitwsd@hello qinshihuang")
var ValidTime = 3600 * 24 * 7

type User struct {
	UserId int64 `json:"user_id"`
}
type CustomClaims struct {
	User
	jwt.StandardClaims
}

func CreateToken(user User) (string, error) {
	expire := time.Now().Add(time.Duration(ValidTime) * time.Second)
	claims := &CustomClaims{
		User: user,
		StandardClaims: jwt.StandardClaims{
			ExpiresAt: expire.Unix(),
			IssuedAt:  time.Now().Unix(),
		},
	}

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

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

	return "Bearer " + t, nil
}

func ParseToken(signToken string) (*CustomClaims, error) {
	token, err := jwt.ParseWithClaims(signToken, &CustomClaims{}, func(token *jwt.Token) (interface{}, error) {
		return JwtKey, nil
	})

	if err != nil {
		if ve, ok := err.(*jwt.ValidationError); ok {
			if ve.Errors&jwt.ValidationErrorExpired != 0 {
				return nil, errors.New("token expired")
			}
		}
		return nil, err
	}

	claims, _ := token.Claims.(*CustomClaims)
	if claims == nil || !token.Valid {
		return nil, errors.New("token invalid")
	}

	return claims, nil
}