package picoserial

import (
	"fmt"
	"time"

	"go.bug.st/serial"
	"go.bug.st/serial/enumerator"
)

func FindDevice() (string, error) {
	ports, err := enumerator.GetDetailedPortsList()
	if err != nil {
		return "", fmt.Errorf("enumerating ports: %w", err)
	}
	for _, p := range ports {
		if p.IsUSB {
			return p.Name, nil
		}
	}
	return "", nil
}

type SerialTransport struct {
	port serial.Port
}

func Open(portName string) (*SerialTransport, error) {
	port, err := serial.Open(portName, &serial.Mode{BaudRate: 115200})
	if err != nil {
		return nil, fmt.Errorf("opening %s: %w", portName, err)
	}
	return &SerialTransport{port: port}, nil
}

func (t *SerialTransport) Send(data []byte) error {
	_, err := t.port.Write(data)
	return err
}

func (t *SerialTransport) Receive(timeout time.Duration) ([]byte, error) {
	t.port.SetReadTimeout(timeout)
	var resp []byte
	buf := make([]byte, 256)
	for {
		n, err := t.port.Read(buf)
		if n > 0 {
			resp = append(resp, buf[:n]...)
		}
		if err != nil || n == 0 {
			break
		}
	}
	return resp, nil
}

func (t *SerialTransport) Close() error {
	return t.port.Close()
}