package protocol

import (
	"log"
	"os"
	"strconv"
)

// Debug reports whether verbose per-URB tracing is enabled, via USBSRV_DEBUG=1.
//
// This tracing is genuinely useful when a device misbehaves, but it must stay
// off by default: an active webcam or audio device produces thousands of URBs
// per second, and logging each one costs more time than forwarding it.
var Debug = debugEnabled()

func debugEnabled() bool {
	v := os.Getenv("USBSRV_DEBUG")
	if v == "" {
		return false
	}
	on, err := strconv.ParseBool(v)
	return err == nil && on
}

// Debugf logs only when debug tracing is enabled.
func Debugf(format string, args ...interface{}) {
	if Debug {
		log.Printf(format, args...)
	}
}