# /etc/udev/rules.d/99-midi.rules
# USB MIDI device hotplug rules for Raspberry Pi RT Audio Mixer
#
# These rules:
#   1. Give the 'audio' group read/write access to USB MIDI devices
#   2. Create a persistent symlink for known controllers
#   3. Trigger systemd service reload on hotplug
#   4. Set nice/rtprio for MIDI processing threads
#
# Install: sudo cp config/99-midi.rules /etc/udev/rules.d/
# Reload:   sudo udevadm control --reload-rules && sudo udevadm trigger

# ── Generic USB MIDI class devices (class-compliant) ────────────────────────

# USB Audio Class MIDI Streaming (subclass 0x03)
SUBSYSTEM=="sound", ACTION=="add", KERNEL=="midi*", \
    GROUP="audio", MODE="0660", \
    TAG+="systemd", ENV{SYSTEMD_WANTS}+="midi-hotplug@$devpath.service"

# ── Known controllers — persistent symlinks by VID:PID ──────────────────────

# Behringer X-Touch Compact
SUBSYSTEM=="sound", ACTION=="add", KERNEL=="midi*", \
    ATTRS{idVendor}=="1397", ATTRS{idProduct}=="00b4", \
    SYMLINK+="midi/xtouch-compact", \
    ENV{MIDI_CONTROLLER}="Behringer X-Touch Compact"

# Behringer X-Touch (MCU mode)
SUBSYSTEM=="sound", ACTION=="add", KERNEL=="midi*", \
    ATTRS{idVendor}=="1397", ATTRS{idProduct}=="00b5", \
    SYMLINK+="midi/xtouch", \
    ENV{MIDI_CONTROLLER}="Behringer X-Touch"

# FaderFox UC4
SUBSYSTEM=="sound", ACTION=="add", KERNEL=="midi*", \
    ATTRS{idVendor}=="16d0", ATTRS{idProduct}=="0d27", \
    SYMLINK+="midi/faderfox-uc4", \
    ENV{MIDI_CONTROLLER}="FaderFox UC4"

# Akai MIDImix
SUBSYSTEM=="sound", ACTION=="add", KERNEL=="midi*", \
    ATTRS{idVendor}=="09e8", ATTRS{idProduct}=="0031", \
    SYMLINK+="midi/midimix", \
    ENV{MIDI_CONTROLLER}="Akai MIDImix"

# Arturia BeatStep
SUBSYSTEM=="sound", ACTION=="add", KERNEL=="midi*", \
    ATTRS{idVendor}=="1c75", ATTRS{idProduct}=="0208", \
    SYMLINK+="midi/beatstep", \
    ENV{MIDI_CONTROLLER}="Arturia BeatStep"

# Novation Launch Control XL
SUBSYSTEM=="sound", ACTION=="add", KERNEL=="midi*", \
    ATTRS{idVendor}=="1235", ATTRS{idProduct}=="0061", \
    SYMLINK+="midi/launchcontrol-xl", \
    ENV{MIDI_CONTROLLER}="Novation Launch Control XL"

# Korg nanoKONTROL2
SUBSYSTEM=="sound", ACTION=="add", KERNEL=="midi*", \
    ATTRS{idVendor}=="0944", ATTRS{idProduct}=="0117", \
    SYMLINK+="midi/nanokontrol2", \
    ENV{MIDI_CONTROLLER}="Korg nanoKONTROL2"

# ── Cleanup on removal ──────────────────────────────────────────────────────

SUBSYSTEM=="sound", ACTION=="remove", KERNEL=="midi*", \
    RUN+="/usr/bin/systemctl stop midi-hotplug@$devpath.service || true"