package utils

import (
	commonConfig "base-framework/pkg/config"
	"errors"
	"time"

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

var (
	ErrTokenExpired = errors.New("token expired")
	ErrTokenInvalid = errors.New("token invalid")
)

// CustomClaims 定义自己的 payload 结构
type CustomClaims struct {
	OrgID  string `json:"org_id"`
	UserID string `json:"user_id"`
	jwt.StandardClaims
}

// CreateToken 创建一个 JWT token
func CreateToken(orgID, userID string) (string, error) {
	expireTime := time.Now().Add(commonConfig.JWT.Expiry).Unix()

	claims := CustomClaims{
		OrgID:  orgID,
		UserID: userID,
		StandardClaims: jwt.StandardClaims{
			ExpiresAt: expireTime,
			IssuedAt:  time.Now().Unix(),
		},
	}

	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
	signKey := []byte(commonConfig.JWT.Secret)
	return token.SignedString(signKey)
}

// VerifyToken 验证并解析 JWT token
func VerifyToken(tokenString string) (*CustomClaims, error) {
	signKey := []byte(commonConfig.JWT.Secret)

	token, err := jwt.ParseWithClaims(tokenString, &CustomClaims{}, func(token *jwt.Token) (interface{}, error) {
		// 校验签名算法
		if _, ok := token.Method.(*jwt.SigningMethodHMAC); !ok {
			return nil, ErrTokenInvalid
		}
		return signKey, nil
	})

	if err != nil {
		// 判断是否过期错误
		if ve, ok := err.(*jwt.ValidationError); ok {
			if ve.Errors&jwt.ValidationErrorExpired != 0 {
				return nil, ErrTokenExpired
			}
		}
		return nil, ErrTokenInvalid
	}

	if claims, ok := token.Claims.(*CustomClaims); ok && token.Valid {
		return claims, nil
	}

	return nil, ErrTokenInvalid
}