dmxconnect/hardware/FTDIDriver.go

package hardware

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

	"github.com/rs/zerolog/log"
)

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

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

// NewFTDIDriver creates a new FTDI finder
func NewFTDIDriver() *FTDIDriver {
	log.Trace().Str("file", "FTDIDriver").Msg("FTDI driver created")
	return &FTDIDriver{
		peripherals: make(map[string]Peripheral),
	}
}

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

// Initialize initializes the FTDI driver
func (d *FTDIDriver) Initialize() error {
	// Check platform
	if goRuntime.GOOS != "windows" {
		log.Error().Str("file", "FTDIDriver").Str("platform", goRuntime.GOOS).Msg("FTDI driver not compatible with your platform")
		return fmt.Errorf("<!> The FTDI driver is not compatible with your platform yet (%s)", goRuntime.GOOS)
	}
	log.Trace().Str("file", "FTDIDriver").Msg("FTDI driver initialized")
	return nil
}

// GetName returns the name of the driver
func (d *FTDIDriver) GetName() string {
	return "FTDI"
}

// GetPeripheral gets the peripheral that correspond to the specified ID
func (d *FTDIDriver) GetPeripheral(peripheralID string) (Peripheral, bool) {
	// Return the specified peripheral
	peripheral := d.peripherals[peripheralID]
	if peripheral == nil {
		log.Error().Str("file", "FTDIDriver").Str("peripheralID", peripheralID).Msg("unable to get this peripheral from the FTDI driver")
		return nil, false
	}
	log.Debug().Str("file", "FTDIDriver").Str("peripheralID", peripheralID).Msg("peripheral found by the FTDI driver")
	return peripheral, true
}

// Scan scans the FTDI peripherals
func (d *FTDIDriver) Scan(ctx context.Context) error {
	log.Trace().Str("file", "FTDIDriver").Msg("FTDI scan triggered")
	time.Sleep(scanDelay)

	// Create a temporary file
	tempFile, err := os.CreateTemp("", "findFTDI*.exe")
	if err != nil {
		return err
	}
	defer os.Remove(tempFile.Name())
	log.Trace().Str("file", "FTDIDriver").Msg("has created the FIND executable temp")

	// Write the embedded executable to the temp file
	if _, err := tempFile.Write(findFTDI); err != nil {
		return err
	}
	tempFile.Close()
	log.Trace().Str("file", "FTDIDriver").Msg("has written the FIND executable")

	ftdiPeripherals := make(map[string]Peripheral)

	finder := exec.Command(tempFile.Name())
	log.Trace().Str("file", "FTDIDriver").Msg("has executed the FIND executable")

	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() {
		peripheralString := 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
		peripheralInfo := strings.Split(peripheralString, ":")

		log.Debug().Str("file", "FTDIDriver").Str("peripheralName", peripheralInfo[2]).Str("peripheralSN", peripheralInfo[1]).Msg("new FTDI peripheral detected")
		// Convert the location to an integer
		location, err := strconv.Atoi(peripheralInfo[0])
		if err != nil {
			log.Warn().Str("file", "FTDIDriver").Str("peripheralName", peripheralInfo[2]).Msg("no location provided for this FTDI peripheral")
			location = -1
		}
		// Add the peripheral to the temporary list
		peripheral, err := NewFTDIPeripheral(peripheralInfo[2], peripheralInfo[1], location)
		if err != nil {
			return fmt.Errorf("Unable to create the FTDI peripheral: %v", err)
		}
		ftdiPeripherals[peripheralInfo[1]] = peripheral
		log.Trace().Str("file", "FTDIDriver").Str("peripheralName", peripheralInfo[2]).Msg("successfully added the FTDI peripheral to the driver")
	}
	// Compare with the current peripherals to detect arrivals/removals
	removedList, addedList := comparePeripherals(d.peripherals, ftdiPeripherals)
	// Emit the events
	emitPeripheralsEvents(ctx, removedList, PeripheralRemoval)
	log.Info().Str("file", "FTDIDriver").Msg("FTDI remove list emitted to the front")
	emitPeripheralsEvents(ctx, addedList, PeripheralArrival)
	log.Info().Str("file", "FTDIDriver").Msg("FTDI add list emitted to the front")
	// Store the new peripherals list
	d.peripherals = ftdiPeripherals
	return nil
}

// CreatePeripheral is not implemented here
func (d *FTDIDriver) CreatePeripheral(context.Context) (Peripheral, error) {
	return nil, nil
}

// RemovePeripheral is not implemented here
func (d *FTDIDriver) RemovePeripheral(serialNumber string) error {
	return nil
}