package communication

import (
	"fmt"
	"log"

	"go.bug.st/serial"
)

type SerialInterface struct {
	port serial.Port
}

func NewSerialInterface() (SerialInterface, error) {
	iface := SerialInterface{}

	devices, err := getStSerials()
	if err != nil {
		return iface, err
	}

	if len(devices) != 1 {
		return iface, fmt.Errorf("Require exactly one serial device from STMicroelectronics but %d attached", len(devices))
	}
	device := devices[0]

	iface.port, err = openSerial(device)
	if err != nil {
		return iface, err
	}

	return iface, nil
}

func (i *SerialInterface) Log() {
	for {
		data, err := i.Read()
		if err != nil {
			log.Fatal(err)
		}
		log.Printf("RX: '%s'\n", string(data))
	}
}

func (i *SerialInterface) Read() ([]byte, error) {
	buff := make([]byte, 100)
	n, err := i.port.Read(buff)
	if err != nil {
		return []byte{}, err
	}
	return buff[:n], nil
}