2 files changed, 122 insertions, 4 deletions

diff --git a/pkg/controller/controller.go b/pkg/controller/controller.go
index b8d04e7..ab04fcc 100644
--- a/pkg/controller/controller.go
+++ b/pkg/controller/controller.go
@@ -22,17 +22,130 @@
 
 package controller
 
+import (
+	"errors"
+	"fmt"
+	"log"
+	"strings"
+
+	"github.com/scgolang/midi"
+)
+
+const (
+	BUTTON_ON          = byte(0x90)
+	BUTTON_OFF         = byte(0x80)
+	NOTE_OFFSET_BUTTON = byte(0x00)
+	NUM_BUTTONS        = 4
+
+	LED_CC          = byte(0xB0)
+	NOTE_OFFSET_LED = byte(0x00)
+	NUM_LEDS        = 4
+	LED_OFF         = byte(0x00)
+	LED_ON          = byte(0x01)
+	LED_TOGGLE      = byte(0x02)
+	LED_BLINK_MIN   = byte(0x03)
+	LED_BLINK_MAX   = byte(0x7f)
+)
+
 type Controller struct {
+	Dev *midi.Device
+}
+
+func openDevice(devices []*midi.Device, prefix string) (d *midi.Device, err error) {
+	for _, device := range devices {
+		if strings.HasPrefix(device.Name, prefix) {
+			d = device
+		}
+	}
+	if d == nil {
+		return nil, errors.New("could not find device with prefix: " + prefix)
+	}
+	return d, d.Open()
 }
 
 func NewController(c Config) (*Controller, error) {
-	return &Controller{}, nil
+	devices, err := midi.Devices()
+	if err != nil {
+		return nil, err
+	}
+
+	ctrl := &Controller{}
+	if ctrl.Dev, err = openDevice(devices, c.Dev); err != nil {
+		return nil, err
+	}
+	ctrl.Dev.QueueSize = 100
+
+	return ctrl, nil
+}
+
+func (c *Controller) handleMidiPacket(p midi.Packet) {
+	num := p.Data[1]
+	switch p.Data[0] {
+	case BUTTON_ON:
+		log.Printf("controller: button %d pressed", num)
+	case BUTTON_OFF:
+		log.Printf("controller: button %d released", num)
+	default:
+		// ignore all other events
+		return
+	}
 }
 
-func (m *Controller) Init() error {
+func (c *Controller) Init() error {
+	ch, err := c.Dev.Packets()
+	if err != nil {
+		return err
+	}
+
+	go func() {
+		for {
+			// TODO: handle Errors (reopen the device!)
+			c.handleMidiPacket(<-ch)
+		}
+	}()
 	return nil
 }
 
-func (m *Controller) Shutdown() error {
+func (c *Controller) Shutdown() error {
+	if c.Dev != nil {
+		c.Dev.Close()
+	}
+	// TODO: also close all subscribed channels
+	//       terminate go-routine started by Init()
 	return nil
 }
+
+func (c *Controller) setLed(num byte, value byte) error {
+	if num >= NUM_LEDS {
+		return fmt.Errorf("this controller has only %d leds.", NUM_LEDS)
+	}
+
+	n, err := c.Dev.Write([]byte{LED_CC, NOTE_OFFSET_LED + num, value})
+	if err != nil {
+		// reopen device?
+		return err
+	}
+	if n != 3 {
+		return errors.New("sending LED command failed.")
+	}
+	return nil
+}
+
+func (c *Controller) LedOff(num byte) error {
+	return c.setLed(num, LED_OFF)
+}
+
+func (c *Controller) LedOn(num byte) error {
+	return c.setLed(num, LED_ON)
+}
+
+func (c *Controller) LedToggle(num byte) error {
+	return c.setLed(num, LED_TOGGLE)
+}
+
+func (c *Controller) LedBlink(num, wait byte) error {
+	if (wait + LED_BLINK_MIN) > LED_BLINK_MAX {
+		return fmt.Errorf("blink wait must be between 0 and %d.", LED_BLINK_MAX-LED_BLINK_MIN)
+	}
+	return c.setLed(num, wait+LED_BLINK_MIN)
+}
diff --git a/pkg/mixer/mixer.go b/pkg/mixer/mixer.go
index 7b46abc..6e8eb07 100644
--- a/pkg/mixer/mixer.go
+++ b/pkg/mixer/mixer.go
@@ -127,7 +127,7 @@ func openDevice(devices []*midi.Device, prefix string) (d *midi.Device, err erro
 		}
 	}
 	if d == nil {
-		return nil, errors.New("could not find device with prefix " + prefix)
+		return nil, errors.New("could not find device with prefix: " + prefix)
 	}
 	return d, d.Open()
 }
@@ -203,6 +203,7 @@ func (m *Mixer) Init() error {
 
 	go func() {
 		for {
+			// TODO: handle Errors (reopen the device!)
 			m.handleMidiPacket(<-ch)
 		}
 	}()
@@ -216,12 +217,15 @@ func (m *Mixer) Shutdown() error {
 	if m.DevOut != nil {
 		m.DevOut.Close()
 	}
+	// TODO: also close all subscribed channels
+	//       terminate go-routine started by Init()
 	return nil
 }
 
 func (m *Mixer) sendMute(channel byte, value byte) error {
 	n, err := m.DevOut.Write([]byte{CC_MUTE, channel, value})
 	if err != nil {
+		// reopen device?
 		return err
 	}
 	if n != 3 {
@@ -244,6 +248,7 @@ func (m *Mixer) SetLevel(ch Channel, level FaderLevel) error {
 	}
 	n, err := m.DevOut.Write([]byte{CC_FADER, byte(ch), byte(level)})
 	if err != nil {
+		// reopen device?
 		return err
 	}
 	if n != 3 {