package utils

import (
	"github.com/tarm/serial"
	"io"
	"log"
	"time"
)

var(
	device string
	baudrate int
	bytesize byte
	port  *serial.Port
	portOpened bool
)

func OpenPort(device string, baudrate int, bytesize byte) error {
	log.Println("opening port device:", device, ", baudrate=", baudrate, ", bytesize=",bytesize)
	config := &serial.Config{Name: device, Baud: baudrate, Size: bytesize, ReadTimeout: time.Second * 1}
	var err error
	port, err = serial.OpenPort(config)
	if err!=nil {
		log.Fatalln("error in open serial port ",   err)
		return err
	}
	log.Println("opened port ", port)
	portOpened = true
	return nil
}

func ReadPort() ([]byte, int){
	buffer := make([]byte, 256)
	count,err := port.Read(buffer)
	if err != nil && err != io.EOF {
		log.Println("error in read port ", err)
		//TODO: 3 time fail try to
	}
	return buffer, count
}

func IsPortOpen() bool {
	return portOpened
}