#!/bin/bash
# on-usb-role-change.sh — Called by udev on USB role/connect events.
# Re-detects role, stops/restarts Pd with appropriate config.

set -euo pipefail

ROLE_FILE="/run/usb-role"
LOG_TAG="[USB-HOTPLUG]"

# Debounce: skip if we just ran (within 3s)
LOCK="/tmp/usb-role-change.lock"
if [ -f "$LOCK" ]; then
    age=$(($(date +%s) - $(stat -c %Y "$LOCK" 2>/dev/null || echo 0)))
    [ "$age" -lt 3 ] && exit 0
fi
touch "$LOCK"

logger -t "$LOG_TAG" "USB role change event — re-detecting..."

/usr/local/bin/detect-usb-role.sh

# Restart Pd if it's running
if systemctl is-active pd-synth-auto &>/dev/null; then
    logger -t "$LOG_TAG" "Restarting Pd with new role"
    systemctl restart pd-synth-auto
fi