package jwt

import (
	"errors"
	"time"

	"github.com/golang-jwt/jwt/v5"
)

var (
	// Token 有效期（7天）
	TokenExpireTime = time.Hour * 24 * 7

	// 签名
	SigningKey = []byte("base-jwt-secret-key-2024")
)

type Claims struct {
	UserID   int64  `json:"userId"`
	Username string `json:"username"`
	Role     string `json:"role"`
	jwt.RegisteredClaims
}

// GenerateToken 生成 JWT Token
func GenerateToken(userId int64, username, role string) (string, error) {
	claims := Claims{
		UserID:   userId,
		Username: username,
		Role:     role,
		RegisteredClaims: jwt.RegisteredClaims{
			ExpiresAt: jwt.NewNumericDate(time.Now().Add(TokenExpireTime)),
			Issuer:    "base-api",
		},
	}

	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
	return token.SignedString(SigningKey)
}

// ParseToken 解析并验证 JWT Token
func ParseToken(tokenString string) (*Claims, error) {
	token, err := jwt.ParseWithClaims(tokenString, &Claims{}, func(token *jwt.Token) (interface{}, error) {
		if _, ok := token.Method.(*jwt.SigningMethodHMAC); !ok {
			return nil, errors.New("invalid signing method")
		}
		return SigningKey, 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")
}