package utility

import (
	"crypto/sha256"
	"encoding/hex"
	"time"

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

var jwtSecret = []byte("your_secret_key") // 建议放到配置文件

type Claims struct {
	UserID int64 `json:"user_id"`
	jwt.RegisteredClaims
}

// GenerateToken 生成 JWT Token
func GenerateToken(userID int64) (string, error) {
	claims := Claims{
		UserID: userID,
		RegisteredClaims: jwt.RegisteredClaims{
			ExpiresAt: jwt.NewNumericDate(time.Now().Add(24 * time.Hour)),
			IssuedAt:  jwt.NewNumericDate(time.Now()),
		},
	}
	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
	return token.SignedString(jwtSecret)
}

// ParseToken 解析 JWT Token
func ParseToken(tokenString string) (*Claims, error) {
	token, err := jwt.ParseWithClaims(tokenString, &Claims{}, func(token *jwt.Token) (interface{}, error) {
		return jwtSecret, nil
	})
	if err != nil {
		return nil, err
	}
	if claims, ok := token.Claims.(*Claims); ok && token.Valid {
		return claims, nil
	}
	return nil, err
}

// HashPassword 对密码+salt做sha256加密
func HashPassword(password, salt string) string {
	h := sha256.New()
	h.Write([]byte(password + salt))
	return hex.EncodeToString(h.Sum(nil))
}