package jwt

import (
	"time"

	"github.com/golang-jwt/jwt/v5"
	"github.com/gogf/gf/v2/frame/g"
	"github.com/gogf/gf/v2/os/gctx"
)

// Claims JWT载荷
type Claims struct {
	UserID   uint   `json:"user_id"`
	Username string `json:"username"`
	UserType string `json:"user_type"` // user, admin
	jwt.RegisteredClaims
}

// GenerateToken 生成Token
func GenerateToken(userID uint, username, userType string) (string, error) {
	var (
		ctx        = gctx.New()
		signingKey = g.Cfg().MustGet(ctx, "jwt.signingKey").String()
		expire     = g.Cfg().MustGet(ctx, "jwt.expire").Int()
	)

	claims := Claims{
		UserID:   userID,
		Username: username,
		UserType: userType,
		RegisteredClaims: jwt.RegisteredClaims{
			ExpiresAt: jwt.NewNumericDate(time.Now().Add(time.Duration(expire) * time.Second)),
			IssuedAt:  jwt.NewNumericDate(time.Now()),
			NotBefore: jwt.NewNumericDate(time.Now()),
		},
	}

	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
	return token.SignedString([]byte(signingKey))
}

// ParseToken 解析Token
func ParseToken(tokenString string) (*Claims, error) {
	var (
		ctx        = gctx.New()
		signingKey = g.Cfg().MustGet(ctx, "jwt.signingKey").String()
	)

	token, err := jwt.ParseWithClaims(tokenString, &Claims{}, func(token *jwt.Token) (interface{}, error) {
		return []byte(signingKey), nil
	})

	if err != nil {
		return nil, err
	}

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

	return nil, jwt.ErrSignatureInvalid
}

// RefreshToken 刷新Token
func RefreshToken(tokenString string) (string, error) {
	claims, err := ParseToken(tokenString)
	if err != nil {
		return "", err
	}

	// 生成新的Token
	return GenerateToken(claims.UserID, claims.Username, claims.UserType)
}