MetaLab/internal/middleware/auth.go

package middleware

import (
	"log"
	"net/http"
	"strings"
	"time"

	"metazone.cc/metalab/internal/common"
	"metazone.cc/metalab/internal/config"

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

// AuthMiddleware 认证中间件（结构体模式，持有 DB 依赖用于实时令牌吊销校验）
type AuthMiddleware struct {
	cfg      *config.Config
	userRepo tokenVersionStore
}

// NewAuthMiddleware 构造函数
func NewAuthMiddleware(cfg *config.Config, userRepo tokenVersionStore) *AuthMiddleware {
	return &AuthMiddleware{cfg: cfg, userRepo: userRepo}
}

// Required 登录认证中间件：校验 JWT → 检查 token_version → 注入用户信息
// 令牌版本与 DB 不匹配时即时拒绝，实现实时吊销
func (am *AuthMiddleware) Required() gin.HandlerFunc {
	return func(c *gin.Context) {
		claims, err := am.authenticateToken(c)
		if err != nil {
			common.ClearAuthCookies(c, am.cfg)
			c.AbortWithStatusJSON(401, gin.H{
				"success": false, "message": "登录已过期，请重新登录",
			})
			return
		}

		injectUserContext(c, claims)
		c.Next()
	}
}

// Optional 可选认证：已登录且版本通过则注入，未登录或版本不匹配也放行（仅清除过期 Cookie）
func (am *AuthMiddleware) Optional() gin.HandlerFunc {
	return func(c *gin.Context) {
		claims, err := am.authenticateToken(c)
		if err != nil {
			log.Printf("[AuthOptional] token invalid for %s: %v", c.Request.URL.Path, err)
			c.Next()
			return
		}

		log.Printf("[AuthOptional] OK: uid=%v username=%v path=%s", claims["uid"], claims["username"], c.Request.URL.Path)
		injectUserContext(c, claims)
		c.Next()
	}
}

// AdminAuth 管理后台页面认证：失败时 302 跳首页而非返回 JSON
func (am *AuthMiddleware) AdminAuth() gin.HandlerFunc {
	return func(c *gin.Context) {
		claims, err := am.authenticateToken(c)
		if err != nil {
			log.Printf("[AdminAuth] auth failed path=%s err=%v → 302", c.Request.URL.Path, err)
			common.ClearAuthCookies(c, am.cfg)
			c.Redirect(http.StatusFound, "/")
			c.Abort()
			return
		}

		log.Printf("[AdminAuth] OK: uid=%d role=%v path=%s", uint(claims["uid"].(float64)), claims["role"], c.Request.URL.Path)
		injectUserContext(c, claims)
		c.Next()
	}
}

// authenticateToken 统一的认证核心流程：读 Cookie → 解析 JWT → 检查 token_version
// 成功返回 claims，失败返回 error（调用方自行决定如何响应）
func (am *AuthMiddleware) authenticateToken(c *gin.Context) (jwt.MapClaims, error) {
	tokenStr, err := c.Cookie(common.CookieName)
	if err != nil {
		return nil, err
	}

	claims, err := parseToken(tokenStr, am.cfg.JWT.Secret)
	if err != nil {
		return nil, err
	}

	uid := uint(claims["uid"].(float64))
	tokenVer := int(claims["ver"].(float64))

	currentVer, err := am.userRepo.FindTokenVersion(uid)
	if err != nil || tokenVer != currentVer {
		if tokenVer != currentVer {
			log.Printf("[authenticateToken] REVOKED: uid=%d tokenVer=%d dbVer=%d", uid, tokenVer, currentVer)
		}
		return nil, err
	}

	return claims, nil
}

// injectUserContext 将 JWT claims 中的用户信息注入 gin context
func injectUserContext(c *gin.Context, claims jwt.MapClaims) {
	c.Set("uid", uint(claims["uid"].(float64)))
	c.Set("email", claims["email"])
	c.Set("username", claims["username"])
	c.Set("role", claims["role"])
}

// parseToken 解析并验证 JWT
func parseToken(tokenStr, secret string) (jwt.MapClaims, error) {
	now := time.Now()
	token, err := jwt.Parse(tokenStr, func(t *jwt.Token) (interface{}, error) {
		return []byte(secret), nil
	})
	if err != nil || !token.Valid {
		log.Printf("[parseToken] FAIL: now=%v err=%v (secret_len=%d token_len=%d)",
			now, err, len(secret), len(tokenStr))
		return nil, err
	}
	claims, ok := token.Claims.(jwt.MapClaims)
	if !ok {
		return nil, jwt.ErrSignatureInvalid
	}
	// Debug: 打印 exp/iat 对比当前时间
	if exp, exists := claims["exp"]; exists {
		var expTime time.Time
		switch v := exp.(type) {
		case float64:
			expTime = time.Unix(int64(v), 0)
		case *jwt.NumericDate:
			expTime = v.Time
		}
		if !expTime.IsZero() {
			log.Printf("[parseToken] OK: exp=%v (%d) now=%v isExpired=%v",
				expTime, expTime.Unix(), now, now.After(expTime))
		}
	}
	return claims, nil
}

// IsLoginPage 检查是否已在登录状态，已登录用户跳过登录/注册页
func IsLoginPage(c *gin.Context) bool {
	return strings.HasPrefix(c.Request.URL.Path, "/auth/")
}