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
}

func Open(portName string) (serial.Port, error) {
	return serial.Open(portName, &serial.Mode{BaudRate: 115200})
}

// SendAndReceive sends data and reads the response with a timeout.
func SendAndReceive(portName string, data []byte, timeout time.Duration) ([]byte, error) {
	port, err := Open(portName)
	if err != nil {
		return nil, fmt.Errorf("opening %s: %w", portName, err)
	}
	defer port.Close()

	port.SetReadTimeout(timeout)

	_, err = port.Write(data)
	if err != nil {
		return nil, fmt.Errorf("writing to %s: %w", portName, err)
	}

	var resp []byte
	buf := make([]byte, 256)
	for {
		n, err := port.Read(buf)
		if n > 0 {
			resp = append(resp, buf[:n]...)
		}
		if err != nil || n == 0 {
			break
		}
	}
	return resp, nil
}