add midi processor to create messages

2026-04-26 21:05:30 +00:00 · 2025-12-16 19:54:21 -06:00
parent f3aaa86a1c
commit 32d8633402
1 changed files with 213 additions and 0 deletions
--- a/internal/processor/midi-message-create.go
+++ b/internal/processor/midi-message-create.go
@@ -0,0 +1,213 @@
+//go:build cgo
+
+package processor
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"strconv"
+	"text/template"
+
+	"github.com/jwetzell/showbridge-go/internal/config"
+	"gitlab.com/gomidi/midi/v2"
+)
+
+type MIDIMessageCreate struct {
+	config      config.ProcessorConfig
+	ProcessFunc func(ctx context.Context, payload any) (any, error)
+}
+
+func (mmd *MIDIMessageCreate) Process(ctx context.Context, payload any) (any, error) {
+	return mmd.ProcessFunc(ctx, payload)
+}
+
+func (mmd *MIDIMessageCreate) Type() string {
+	return mmd.config.Type
+}
+
+func newMidiNoteOnCreate(config config.ProcessorConfig) (Processor, error) {
+
+	params := config.Params
+
+	channel, ok := params["channel"]
+
+	if !ok {
+		return nil, fmt.Errorf("midi.message.create NoteOn requires a channel parameter")
+	}
+
+	channelString, ok := channel.(string)
+
+	if !ok {
+		return nil, fmt.Errorf("midi.message.create NoteOn channel must be a string")
+	}
+
+	channelTemplate, err := template.New("channel").Parse(channelString)
+
+	if err != nil {
+		return nil, err
+	}
+
+	note, ok := params["note"]
+
+	if !ok {
+		return nil, fmt.Errorf("midi.message.create NoteOn requires a note parameter")
+	}
+
+	noteString, ok := note.(string)
+
+	if !ok {
+		return nil, fmt.Errorf("midi.message.create NoteOn note must be a string")
+	}
+
+	noteTemplate, err := template.New("note").Parse(noteString)
+
+	if err != nil {
+		return nil, err
+	}
+
+	velocity, ok := params["velocity"]
+
+	if !ok {
+		return nil, fmt.Errorf("midi.message.create NoteOn requires a velocity parameter")
+	}
+
+	velocityString, ok := velocity.(string)
+
+	if !ok {
+		return nil, fmt.Errorf("midi.message.create NoteOn velocity must be a string")
+	}
+
+	velocityTemplate, err := template.New("velocity").Parse(velocityString)
+
+	if err != nil {
+		return nil, err
+	}
+
+	return &MIDIMessageCreate{config: config, ProcessFunc: func(ctx context.Context, payload any) (any, error) {
+
+		var channelBuffer bytes.Buffer
+		err := channelTemplate.Execute(&channelBuffer, payload)
+
+		if err != nil {
+			return nil, err
+		}
+
+		channelValue, err := strconv.ParseUint(channelBuffer.String(), 10, 8)
+
+		var noteBuffer bytes.Buffer
+		err = noteTemplate.Execute(&noteBuffer, payload)
+
+		if err != nil {
+			return nil, err
+		}
+
+		noteValue, err := strconv.ParseUint(noteBuffer.String(), 10, 8)
+
+		var velocityBuffer bytes.Buffer
+		err = velocityTemplate.Execute(&velocityBuffer, payload)
+
+		if err != nil {
+			return nil, err
+		}
+
+		velocityValue, err := strconv.ParseUint(velocityBuffer.String(), 10, 8)
+		payloadMessage := midi.NoteOn(uint8(channelValue), uint8(noteValue), uint8(velocityValue))
+		return payloadMessage, nil
+	}}, nil
+}
+
+func newMidiNoteOffCreate(config config.ProcessorConfig) (Processor, error) {
+
+	params := config.Params
+
+	channel, ok := params["channel"]
+
+	if !ok {
+		return nil, fmt.Errorf("midi.message.create NoteOn requires a channel parameter")
+	}
+
+	channelString, ok := channel.(string)
+
+	if !ok {
+		return nil, fmt.Errorf("midi.message.create NoteOn channel must be a string")
+	}
+
+	channelTemplate, err := template.New("channel").Parse(channelString)
+
+	if err != nil {
+		return nil, err
+	}
+
+	note, ok := params["note"]
+
+	if !ok {
+		return nil, fmt.Errorf("midi.message.create NoteOn requires a note parameter")
+	}
+
+	noteString, ok := note.(string)
+
+	if !ok {
+		return nil, fmt.Errorf("midi.message.create NoteOn note must be a string")
+	}
+
+	noteTemplate, err := template.New("note").Parse(noteString)
+
+	if err != nil {
+		return nil, err
+	}
+
+	return &MIDIMessageCreate{config: config, ProcessFunc: func(ctx context.Context, payload any) (any, error) {
+
+		var channelBuffer bytes.Buffer
+		err := channelTemplate.Execute(&channelBuffer, payload)
+
+		if err != nil {
+			return nil, err
+		}
+
+		channelValue, err := strconv.ParseUint(channelBuffer.String(), 10, 8)
+
+		var noteBuffer bytes.Buffer
+		err = noteTemplate.Execute(&noteBuffer, payload)
+
+		if err != nil {
+			return nil, err
+		}
+
+		noteValue, err := strconv.ParseUint(noteBuffer.String(), 10, 8)
+
+		payloadMessage := midi.NoteOff(uint8(channelValue), uint8(noteValue))
+		return payloadMessage, nil
+	}}, nil
+}
+
+func init() {
+	RegisterProcessor(ProcessorRegistration{
+		Type: "midi.message.create",
+		New: func(config config.ProcessorConfig) (Processor, error) {
+			params := config.Params
+
+			msgType, ok := params["type"]
+
+			if !ok {
+				return nil, fmt.Errorf("midi.message.create requires a type parameter")
+			}
+
+			msgTypeString, ok := msgType.(string)
+
+			if !ok {
+				return nil, fmt.Errorf("midi.message.create type parameter must be a string")
+			}
+
+			switch msgTypeString {
+			case "NoteOn":
+				return newMidiNoteOnCreate(config)
+			case "NoteOff":
+				return newMidiNoteOffCreate(config)
+			default:
+				return nil, fmt.Errorf("midi.message.create does not support type %s", msgTypeString)
+			}
+		},
+	})
+}