dmxconnect/hardware/MIDIFinder.go

package hardware

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

	"github.com/rs/zerolog/log"
	"gitlab.com/gomidi/rtmididrv"
)

// MIDIFinder represents how the protocol is defined
type MIDIFinder struct {
	wg sync.WaitGroup
	mu sync.Mutex

	detected map[string]*MIDIPeripheral // Detected peripherals

	scanEvery time.Duration // Scans peripherals periodically

	onArrival func(context.Context, Peripheral) // When a peripheral arrives
	onRemoval func(context.Context, Peripheral) // When a peripheral goes away
}

// NewMIDIFinder creates a new MIDI finder
func NewMIDIFinder(scanEvery time.Duration) *MIDIFinder {
	log.Trace().Str("file", "MIDIFinder").Msg("MIDI finder created")
	return &MIDIFinder{
		scanEvery: scanEvery,
		detected:  make(map[string]*MIDIPeripheral),
	}
}

// OnArrival is the callback function when a new peripheral arrives
func (f *MIDIFinder) OnArrival(cb func(context.Context, Peripheral)) {
	f.onArrival = cb
}

// OnRemoval i the callback when a peripheral goes away
func (f *MIDIFinder) OnRemoval(cb func(context.Context, Peripheral)) {
	f.onRemoval = cb
}

// Initialize initializes the MIDI driver
func (f *MIDIFinder) Initialize() error {
	log.Trace().Str("file", "MIDIFinder").Msg("MIDI finder initialized")
	return nil
}

// Create creates a new peripheral, based on the peripheral information (manually created)
func (f *MIDIFinder) Create(ctx context.Context, peripheralInfo PeripheralInfo) (PeripheralInfo, error) {
	return PeripheralInfo{}, nil
}

// Remove removes an existing peripheral (manually created)
func (f *MIDIFinder) Remove(ctx context.Context, peripheral Peripheral) error {
	return nil
}

// Start starts the finder and search for peripherals
func (f *MIDIFinder) Start(ctx context.Context) error {
	f.wg.Add(1)
	go func() {
		ticker := time.NewTicker(f.scanEvery)
		defer ticker.Stop()
		defer f.wg.Done()

		for {
			select {
			case <-ctx.Done():
				return
			case <-ticker.C:
				// Scan the peripherals
				err := f.scanPeripherals(ctx)
				if err != nil {
					log.Err(err).Str("file", "MIDIFinder").Msg("unable to scan MIDI peripherals")
				}
			}
		}
	}()
	return nil
}

// WaitStop stops the finder
func (f *MIDIFinder) WaitStop() error {
	log.Trace().Str("file", "MIDIFinder").Msg("stopping the MIDI finder...")

	// Wait for goroutines to stop
	f.wg.Wait()

	log.Trace().Str("file", "MIDIFinder").Msg("MIDI finder stopped")
	return nil
}

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

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")
}

// scanPeripherals scans the MIDI peripherals
func (f *MIDIFinder) scanPeripherals(ctx context.Context) error {
	currentMap := make(map[string]*MIDIPeripheral)

	drv, err := rtmididrv.New()
	if err != nil {
		return fmt.Errorf("unable to open the MIDI driver")
	}
	defer drv.Close()

	// Get MIDI INPUT ports
	ins, err := drv.Ins()
	if err != nil {
		return fmt.Errorf("unable to scan MIDI IN ports: %s", err)
	}

	for _, port := range ins {
		// Exclude microsoft wavetable from the list
		if strings.Contains(port.String(), "GS Wavetable") {
			continue
		}

		baseName := normalizeName(port.String())
		sn := strings.ReplaceAll(strings.ToLower(baseName), " ", "_")

		if _, ok := currentMap[sn]; !ok {
			currentMap[sn] = &MIDIPeripheral{
				info: PeripheralInfo{
					Name:         baseName,
					SerialNumber: sn,
					ProtocolName: "MIDI",
				},
			}
		}

		currentMap[sn].inputPorts = append(currentMap[sn].inputPorts, port)
		log.Info().Any("peripherals", currentMap).Msg("available MIDI IN ports")
	}

	// Get MIDI OUTPUT ports
	outs, err := drv.Outs()
	if err != nil {
		return fmt.Errorf("unable to scan MIDI OUT ports: %s", err)
	}

	for _, port := range outs {
		// Exclude microsoft wavetable from the list
		if strings.Contains(port.String(), "GS Wavetable") {
			continue
		}
		baseName := normalizeName(port.String())

		sn := strings.ReplaceAll(strings.ToLower(baseName), " ", "_")

		if _, ok := currentMap[sn]; !ok {
			currentMap[sn] = &MIDIPeripheral{
				info: PeripheralInfo{
					Name:         baseName,
					SerialNumber: sn,
					ProtocolName: "MIDI",
				},
			}
		}

		currentMap[sn].outputsPorts = append(currentMap[sn].outputsPorts, port)
		log.Info().Any("peripherals", currentMap).Msg("available MIDI OUT ports")
	}

	log.Debug().Any("value", currentMap).Msg("MIDI peripherals map")

	// Detect arrivals
	for sn, discovery := range currentMap {
		if _, known := f.detected[sn]; !known {

			peripheral := NewMIDIPeripheral(discovery.info, discovery.inputPorts, discovery.outputsPorts)

			f.detected[sn] = peripheral

			if f.onArrival != nil {
				f.onArrival(ctx, discovery)
			}
		}
	}

	// Detect removals
	for sn, oldPeripheral := range f.detected {
		if _, still := currentMap[sn]; !still {

			log.Info().Str("sn", sn).Str("name", oldPeripheral.GetInfo().Name).Msg("[MIDI] peripheral removed")

			// Execute the removal callback
			if f.onRemoval != nil {
				f.onRemoval(ctx, oldPeripheral)
			}

			// Delete it from the detected list
			delete(f.detected, sn)
		}
	}
	return nil
}

func normalizeName(raw string) string {
	name := strings.TrimSpace(raw)

	// Si parenthèses, prendre le texte à l'intérieur
	start := strings.Index(name, "(")
	end := strings.LastIndex(name, ")")
	if start != -1 && end != -1 && start < end {
		name = name[start+1 : end]
		return strings.TrimSpace(name)
	}

	// Sinon, supprimer le dernier mot s'il est un entier
	parts := strings.Fields(name) // découpe en mots
	if len(parts) > 1 {
		if _, err := strconv.Atoi(parts[len(parts)-1]); err == nil {
			parts = parts[:len(parts)-1] // retirer le dernier mot
		}
	}

	return strings.Join(parts, " ")
}