#!/usr/bin/env bash
# Proven Pi-5 configfs gadget: HID keyboard+mouse + stereo UAC2
set -euo pipefail
modprobe libcomposite
# mountpoint -q /sys/kernel/config || mount -t configfs configfs /sys/kernel/config
G=/sys/kernel/config/usb_gadget/navka

if [[ -d $G ]]; then
  echo "" >"$G/UDC" || true
  find "$G/configs" -type l -delete || true
  rmdir "$G/functions/"* 2>/dev/null || true
  rmdir "$G"            2>/dev/null || true
fi

mkdir -p "$G"
echo 0x1d6b >"$G/idVendor"       # Linux Foundation
echo 0x0104 >"$G/idProduct"      # Multifunction Composite Gadget
echo 0x0200 >"$G/bcdUSB"

mkdir -p "$G/strings/0x409"
echo "0001"                 >"$G/strings/0x409/serialnumber"
echo "Navka"                >"$G/strings/0x409/manufacturer"
echo "Navka Composite"      >"$G/strings/0x409/product"

# HID (boot keyboard)
mkdir -p "$G/functions/hid.usb0"
echo 1  >"$G/functions/hid.usb0/protocol"
echo 1  >"$G/functions/hid.usb0/subclass"
echo 8  >"$G/functions/hid.usb0/report_length"
echo -ne '\x05\x01\x09\x06\xa1\x01\x05\x07\x19\xe0\x29\xe7\x15\x00\x25'\
'\x01\x75\x01\x95\x08\x81\x02\x95\x01\x75\x08\x81\x01\x95\x05\x75\x01'\
'\x05\x08\x19\x01\x29\x05\x91\x02\x95\x01\x75\x03\x91\x01\x95\x06\x75'\
'\x08\x15\x00\x25\x65\x05\x07\x19\x00\x29\x65\x81\x00\xc0' \
 >"$G/functions/hid.usb0/report_desc"

# UAC2 stereo 48 kHz
mkdir -p "$G/functions/uac2.usb0"
echo 48000 >"$G/functions/uac2.usb0/c_srate"
echo 2     >"$G/functions/uac2.usb0/c_ssize"
echo 2     >"$G/functions/uac2.usb0/p_chmask"

mkdir -p "$G/configs/c.1/strings/0x409"
echo "Config 1" >"$G/configs/c.1/strings/0x409/configuration"
echo 500        >"$G/configs/c.1/MaxPower"

ln -s "$G/functions/hid.usb0"  "$G/configs/c.1/"
ln -s "$G/functions/uac2.usb0" "$G/configs/c.1/"

echo "$(ls /sys/class/udc | head -n1)" >"$G/UDC"