add the concept of processors

internals/processing/osc-message-transform.go

@@ -0,0 +1,77 @@
+package processing
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"text/template"
+
+	osc "github.com/jwetzell/osc-go"
+)
+
+type OSCMessageTransform struct {
+	config  ProcessorConfig
+	Address *template.Template
+}
+
+func (o *OSCMessageTransform) Process(ctx context.Context, payload any) (any, error) {
+	payloadMessage, ok := payload.(osc.OSCMessage)
+
+	if !ok {
+		return nil, fmt.Errorf("osc.message.transform processor only accepts an OSCMessage")
+	}
+
+	var addressBuffer bytes.Buffer
+	//TODO(jwetzell): actually inject data into template
+	err := o.Address.Execute(&addressBuffer, payloadMessage)
+
+	if err != nil {
+		return nil, err
+	}
+
+	addressString := addressBuffer.String()
+
+	if len(addressString) == 0 {
+		return nil, fmt.Errorf("osc.message.transform address must not be empty")
+	}
+
+	if addressString[0] != '/' {
+		return nil, fmt.Errorf("osc.message.transform address must start with '/'")
+	}
+
+	payloadMessage.Address = addressString
+
+	return payloadMessage, nil
+}
+
+func (o *OSCMessageTransform) Type() string {
+	return o.config.Type
+}
+
+func init() {
+	RegisterProcessor(ProcessorRegistration{
+		Type: "osc.message.transform",
+		New: func(config ProcessorConfig) (Processor, error) {
+			params := config.Params
+			address, ok := params["address"]
+
+			if !ok {
+				return nil, fmt.Errorf("osc.message.transform requires an address parameter")
+			}
+
+			addressString, ok := address.(string)
+
+			if !ok {
+				return nil, fmt.Errorf("osc.message.transform address must be a string")
+			}
+
+			addressTemplate, err := template.New("address").Parse(addressString)
+
+			if err != nil {
+				return nil, err
+			}
+
+			return &OSCMessageTransform{config: config, Address: addressTemplate}, nil
+		},
+	})
+}