package tokenx

import (
	"errors"
	"fmt"
	"time"

	"github.com/golang-jwt/jwt/v4"
)

// Claims JWT 自定义负载
type Claims struct {
	UserId    int    `json:"userId"`
	Username  string `json:"username"`
	Name      string `json:"name"`
	RoleId    int    `json:"roleId"`
	RoleCode  string `json:"roleCode"`
	RoleName  string `json:"roleName"`
	StationNo int    `json:"stationNo,omitempty"` // 工位终端登录时的工位号
	jwt.RegisteredClaims
}

// Issue 签发 JWT
func Issue(secret string, expire time.Duration, c Claims) (string, error) {
	c.IssuedAt = jwt.NewNumericDate(time.Now())
	c.ExpiresAt = jwt.NewNumericDate(time.Now().Add(expire))
	c.Subject = fmt.Sprintf("%d", c.UserId)
	t := jwt.NewWithClaims(jwt.SigningMethodHS256, c)
	return t.SignedString([]byte(secret))
}

// Parse 校验 JWT 并返回负载
func Parse(secret, tokenStr string) (*Claims, error) {
	token, err := jwt.ParseWithClaims(tokenStr, &Claims{}, func(t *jwt.Token) (any, error) {
		if _, ok := t.Method.(*jwt.SigningMethodHMAC); !ok {
			return nil, errors.New("unexpected signing method")
		}
		return []byte(secret), nil
	})
	if err != nil {
		return nil, err
	}
	if claims, ok := token.Claims.(*Claims); ok && token.Valid {
		return claims, nil
	}
	return nil, errors.New("invalid token")
}