app.Use(middleware.RequestID())
app.Use(kern.Logger(kern.LoggerConfig{Format: "json"}))

type statusRecorder struct {
    http.ResponseWriter
    status int
}

func (r *statusRecorder) WriteHeader(code int) {
    r.status = code
    r.ResponseWriter.WriteHeader(code)
}

func ObserveGuardDenies(route string) kern.MiddlewareFunc {
    return func(next http.Handler) http.Handler {
        return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
            rec := &statusRecorder{ResponseWriter: w, status: http.StatusOK}
            next.ServeHTTP(rec, req)
            if rec.status == http.StatusBadRequest {
                log.Printf("guard_deny route=%s method=%s path=%s", route, req.Method, req.URL.Path)
            }
        })
    }
}

app.GET("/me", func(c *kern.Context) {
    rawCookie, _ := c.Cookie("_session")
    session, ok := middleware.GetSession(c.Context())
    if !ok {
        c.NoContent(http.StatusInternalServerError)
        return
    }

    _, hasUser := session.Get("user_id")
    if rawCookie != nil && !hasUser {
        log.Printf("session_cookie_rejected path=%s", c.Request.URL.Path)
    }
})