#!/usr/bin/env bash
# scripts/daemon/lesavka-core.sh - background stealth daemon to present gadget as usb hub of genuine devices
# Proven Pi-5 configfs gadget: HID keyboard+mouse
# Still need Web Cam Support + stereo UAC2

# lesavka-core - one-shot gadget bring-up for Pi-5 / Arch-ARM
set -euo pipefail

# 1) Ensure the dwc2 peripheral overlay is active exactly once
CFG=/boot/config.txt
grep -q 'dtoverlay=dwc2,dr_mode=peripheral' "$CFG" || echo 'dtoverlay=dwc2,dr_mode=peripheral' >> "$CFG"

# 2) Load kernel modules (idempotent)
modprobe dwc2 || { echo "dwc2 not in kernel; abort" >&2; exit 1; }
modprobe libcomposite || { echo "libcomposite not in kernel; abort" >&2; exit 1; }

modprobe -r uvcvideo 2>/dev/null || true
modprobe uvcvideo || { echo "uvcvideo not in kernel; abort" >&2; exit 1; }

udevadm control --reload
udevadm trigger --subsystem-match=video4linux
udevadm settle

echo "[lesavka-core] ⏳ waiting for UDC to register ..."
UDC=""
for _ in {1..100}; do                       # 100 × 100ms = 10s
    UDC=$(ls /sys/class/udc 2>/dev/null | head -n1) && [[ -n $UDC ]] && break
    sleep 0.1
done

if [[ -z $UDC ]]; then
    echo "[lesavka-core] ⚠️  UDC still absent - trying manual bind"
    for drv in dwc2 dwc3; do
        drv_root="/sys/bus/platform/drivers/$drv"
        [[ -d $drv_root ]] || continue
        for node in /sys/bus/platform/devices/*usb*; do
            node=${node##*/}               # strip path → “1000480000.usb”
            echo "$node" >"$drv_root/bind" 2>/dev/null || continue
        done
    done
    # re-check for another 5 s
    for i in {1..50}; do
        UDC=$(ls /sys/class/udc 2>/dev/null | head -n1) && [[ -n $UDC ]] && break
        sleep 0.1
    done
fi

[[ -n $UDC ]] || { echo "❌ UDC not present after manual bind"; exit 1; }
echo "[lesavka-core] ✅ UDC detected: $UDC"

# 3) Mount configfs once
mountpoint -q /sys/kernel/config || mount -t configfs none /sys/kernel/config
G=/sys/kernel/config/usb_gadget/lesavka

# 4) Tear down any previous half-built gadget
if [[ -d $G ]]; then
  echo '' >"$G/UDC" 2>/dev/null || true
  sleep 0.2
  find "$G/configs" -type l -delete 2>/dev/null || true
  rm -rf "$G" 2>/dev/null || true
fi

# 5) Create gadget (boot-keyboard + UAC2 mic/spkr, 500 mA max)
mkdir -p "$G"
echo 0x1d6b >"$G/idVendor"       # Linux Foundation
echo 0x0104 >"$G/idProduct"      # Multifunction Composite Gadget
echo 0x0200 >"$G/bcdUSB"

mkdir -p "$G/strings/0x409"
echo "$(cat /proc/sys/kernel/random/uuid)" >"$G/strings/0x409/serialnumber"
echo "Lesavka"                               >"$G/strings/0x409/manufacturer"
echo "Lesavka Composite"                     >"$G/strings/0x409/product"

# ----------------------- HID keyboard (usb0) -----------------------
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"
printf '\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"

# ----------------------- HID mouse (usb1) --------------------------
mkdir -p "$G/functions/hid.usb1"
echo 2 > "$G/functions/hid.usb1/protocol"   # Boot mouse
echo 1 > "$G/functions/hid.usb1/subclass"
echo 4 > "$G/functions/hid.usb1/report_length"
printf '\x05\x01\x09\x02\xa1\x01\x09\x01\xa1\x00'\
'\x05\x09\x19\x01\x29\x03\x15\x00\x25\x01\x95\x03\x75\x01\x81\x02'\
'\x95\x01\x75\x05\x81\x03'\
'\x05\x01\x09\x30\x09\x31\x09\x38\x15\x81\x25\x7f\x75\x08\x95\x03\x81\x06'\
'\xc0\xc0' >"$G/functions/hid.usb1/report_desc"

# ---------- UAC2 function – speaker + mic, 2×48 kHz stereo ---------
mkdir -p "$G/functions/uac2.usb0"
cfg="$G/functions/uac2.usb0"
echo 48000  >"$cfg/s_spk/freq"
echo 2      >"$cfg/s_spk/chs"   # L+R
echo 16     >"$cfg/s_spk/strm_maxpacket"
echo 48000  >"$cfg/c_mic/freq"
echo 2      >"$cfg/c_mic/chs"
echo 16     >"$cfg/c_mic/strm_maxpacket"

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

# 6) Finally bind to first available UDC
ln -s $G/functions/hid.usb0  $G/configs/c.1/
ln -s $G/functions/hid.usb1  $G/configs/c.1/
ln -sf "$cfg" "$G/configs/c.1/"

# 7) Finally bind to first available UDC
echo "$UDC" > "$G/UDC"
echo "[lesavka-core] 🎉 gadget ready"
echo "⌨️ hidg0 gadget ready on controller $UDC"
echo "🖱️ hidg1 gadget ready on controller $UDC"
echo "🎧 UAC2  gadget ready on controller $UDC"
echo "🎤 UAC2  gadget ready on controller $UDC"