dmxconnect/hardware/FTDIFinder.go

package hardware

import (
	"bufio"
	"context"
	_ "embed"
	"fmt"
	"os"
	"os/exec"
	goRuntime "runtime"
	"strconv"
	"strings"
	"time"
)

const (
	scanDelay = 4 * time.Second // Waiting delay before scanning the FTDI devices
)

// FTDIFinder represents how the protocol is defined
type FTDIFinder struct {
	peripherals map[string]Peripheral
}

// NewFTDIFinder creates a new FTDI finder
func NewFTDIFinder() *FTDIFinder {
	return &FTDIFinder{
		peripherals: make(map[string]Peripheral),
	}
}

// Initialize initializes the FTDI finder
func (f *FTDIFinder) Initialize() error {
	if goRuntime.GOOS != "windows" {
		return fmt.Errorf("<!> The FTDI finder is not compatible with your platform yet (%s)", goRuntime.GOOS)
	}
	fmt.Println("FTDI finder initialized")
	return nil
}

// GetName returns the name of the finder
func (f *FTDIFinder) GetName() string {
	return "FTDI Finder"
}

//go:embed third-party/ftdi/detectFTDI.exe
var findFTDI []byte

// Scan scans the FTDI peripherals
func (f *FTDIFinder) Scan(ctx context.Context) error {
	time.Sleep(scanDelay)

	// Create a temporary file
	tempFile, err := os.CreateTemp("", "findFTDI*.exe")
	if err != nil {
		return err
	}
	defer os.Remove(tempFile.Name())

	// Write the embedded executable to the temp file
	if _, err := tempFile.Write(findFTDI); err != nil {
		return err
	}
	tempFile.Close()

	ftdiPeripherals := make(map[string]Peripheral)

	finder := exec.Command(tempFile.Name())

	stdout, err := finder.StdoutPipe()
	if err != nil {
		return fmt.Errorf("Unable to create the stdout pipe: %s", err)
	}

	stderr, err := finder.StderrPipe()
	if err != nil {
		return fmt.Errorf("Unable to create the stderr pipe: %s", err)
	}

	err = finder.Start()
	if err != nil {
		return fmt.Errorf("Unable to find FTDI devices: %s", err)
	}

	scannerErr := bufio.NewScanner(stderr)
	for scannerErr.Scan() {
		return fmt.Errorf("Unable to find FTDI devices: %s", scannerErr.Text())
	}

	scanner := bufio.NewScanner(stdout)
	for scanner.Scan() {
		deviceString := scanner.Text()
		// The program output is like '0:1:2' where 0 is the location, 1 is the S/N and 2 is the name
		deviceInfo := strings.Split(deviceString, ":")

		fmt.Println("FTDI device: " + deviceString)
		// Convert the location to an integer
		location, err := strconv.Atoi(deviceInfo[0])
		if err != nil {
			location = -1
		}
		// Add the peripheral to the temporary list
		peripheral, err := NewFTDIPeripheral(deviceInfo[2], deviceInfo[1], location)
		if err != nil {
			return fmt.Errorf("Unable to create the FTDI peripheral: %v", err)
		}
		ftdiPeripherals[deviceInfo[1]] = peripheral
	}
	// Compare with the current peripherals to detect arrivals/removals
	removedList, addedList := comparePeripherals(f.peripherals, ftdiPeripherals)
	// Emit the events
	emitPeripheralsEvents(ctx, removedList, PeripheralRemoval)
	emitPeripheralsEvents(ctx, addedList, PeripheralArrival)
	// Store the new peripherals list
	f.peripherals = ftdiPeripherals
	return nil
}