dmxconnect/hardware/MIDIDriver.go

package hardware

import (
	"context"
	"fmt"
	"regexp"
	"strconv"
	"strings"

	"github.com/mattrtaylor/go-rtmidi"
)

// MIDIDriver represents how the protocol is defined
type MIDIDriver struct {
	peripherals map[string]Peripheral // The list of peripherals
}

// NewMIDIDriver creates a new DMXUSB protocol
func NewMIDIDriver() *MIDIDriver {
	return &MIDIDriver{
		peripherals: make(map[string]Peripheral),
	}
}

// Initialize initializes the MIDI driver
func (d *MIDIDriver) Initialize() error {
	fmt.Println("MIDI driver initialized")
	return nil
}

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

// GetPeripheral gets the peripheral that correspond to the specified ID
func (d *MIDIDriver) GetPeripheral(peripheralID string) (Peripheral, bool) {
	// Return the specified peripheral
	peripheral := d.peripherals[peripheralID]
	if peripheral == nil {
		return nil, false
	}
	return peripheral, true
}

func splitStringAndNumber(input string) (string, int, error) {
	// Regular expression to match the text part and the number at the end
	re := regexp.MustCompile(`^(.*?)(\d+)$`)
	matches := re.FindStringSubmatch(input)

	// Check if the regex found both a text part and a number
	if len(matches) == 3 {
		// matches[1]: text part (might contain trailing spaces)
		// matches[2]: numeric part as a string
		textPart := strings.TrimSpace(matches[1]) // Remove any trailing spaces from the text
		numberPart, err := strconv.Atoi(matches[2])
		if err != nil {
			return "", 0, err // Return error if the number conversion fails
		}
		return textPart, numberPart, nil
	}

	// Return an error if no trailing number is found
	return "", 0, fmt.Errorf("no number found at the end of the string")
}

// Scan scans the interfaces compatible with the MIDI protocol
func (d *MIDIDriver) Scan(ctx context.Context) error {
	midiPeripherals := make(map[string]Peripheral)
	fmt.Println("Opening MIDI scanner port...")
	midiScanner, err := rtmidi.NewMIDIInDefault()
	if err != nil {
		return fmt.Errorf("Error when opening the MIDI scanner: %s", err)
	}
	defer midiScanner.Close()
	fmt.Println("Scanning MIDI devices...")
	devicesCount, err := midiScanner.PortCount()
	if err != nil {
		return fmt.Errorf("Error when scanning MIDI devices: %s", err)
	}
	for i := 0; i < devicesCount; i++ {
		portName, err := midiScanner.PortName(i)
		if err != nil {
			portName = "Unknown device 0"
		}
		// Separate data
		name, location, err := splitStringAndNumber(portName)
		if err != nil {
			return fmt.Errorf("Unable to get information from the string: %s", err)
		}
		fmt.Printf("New MIDI device found: %s on %i\n", name, location)
		// Add the peripheral to the temporary list
		sn := strings.ToLower(strings.Replace(name, " ", "_", -1))
		midiPeripherals[sn] = NewMIDIPeripheral(name, location, sn)
	}
	// Compare with the current peripherals to detect arrivals/removals
	removedList, addedList := comparePeripherals(d.peripherals, midiPeripherals)
	// Emit the events
	emitPeripheralsEvents(ctx, removedList, PeripheralRemoval)
	emitPeripheralsEvents(ctx, addedList, PeripheralArrival)
	// Store the new peripherals list
	d.peripherals = midiPeripherals
	return nil
}

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

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