#!/bin/sh
# Camera gesture control (open hand moves the pointer, fist clicks) — OPT-IN, and for
# the specific rooms that are getting a webcam only.
#
# Two independent gates, on purpose. This one is per-image and decides whether the
# software is on the disk at all: MediaPipe plus its OpenCV/numpy/matplotlib tail is a
# few hundred MB, which has no business being in the image of a room that has no camera.
# The second gate is the "enabled" flag in gesture-config.json and decides whether the
# camera is ever OPENED — it defaults to false even on an image built with this hook, so
# flashing a gesture-capable image is not the same act as switching a room's camera on.
#
# A venv rather than apt or `pip3 --break-system-packages`, same reasoning as
# 0600-voice-satellite.hook.chroot: bookworm's system interpreter is PEP 668
# externally-managed, and mediapipe drags in its own opencv-contrib-python and numpy
# which must not overwrite the apt-managed versions the rest of the image uses.
#
# No apt attempt first, unlike 0500/0800: mediapipe has never been packaged in Debian
# (there is no python3-mediapipe in bookworm or trixie) and upstream ships only PyPI
# wheels, so an `apt-get install mediapipe` here would be theatre rather than a real
# fallback. The other half of that convention — fail to a documented placeholder rather
# than to a broken image — does apply, and is what every failure path below does.
set -eu

. /etc/thinclient-agent/config.env

if [ "${ENABLE_GESTURE_CONTROL}" != "true" ]; then
  echo "1100-gesture-control: ENABLE_GESTURE_CONTROL is false, skipping (this is the"
  echo "  default — only images destined for a room that is getting a webcam should"
  echo "  enable it, exactly as with ENABLE_VOICE_SATELLITE and microphones)."
  exit 0
fi

VENV=/opt/gesture-control/venv
MODEL=/opt/gesture-control/hand_landmarker.task

# The published MediaPipe Hand Landmarker bundle. This IS a hardcoded URL, which the
# rest of this tree avoids — the justification is that the trailing path is Google's own
# `/latest/` alias rather than a version tag, so it does not rot the way a pinned GitHub
# release tag does, and since mediapipe 1.0.0 dropped the legacy mediapipe.solutions
# package the model no longer ships inside the wheel. VERIFY it still resolves if the
# download below starts failing:
#   https://ai.google.dev/edge/mediapipe/solutions/vision/hand_landmarker#models
MODEL_URL="https://storage.googleapis.com/mediapipe-models/hand_landmarker/hand_landmarker/float16/latest/hand_landmarker.task"

python3 -m venv "$VENV"
"$VENV/bin/pip" install --upgrade pip wheel setuptools

# mediapipe pulls opencv-contrib-python itself, so there is nothing to install for the
# capture side. Debian's own python3-opencv is deliberately NOT used: it does not satisfy
# mediapipe's opencv-contrib-python requirement, so listing it would only put a second
# copy of OpenCV on the image. The apt packages this needs are the shared libraries those
# wheels dlopen at runtime, and they are in thin-client.list.chroot.
if ! "$VENV/bin/pip" install mediapipe; then
  echo "1100-gesture-control: WARNING — 'pip install mediapipe' failed. Gesture control"
  echo "  will not work on this image; nothing else is affected (the sway wrapper detects"
  echo "  the missing venv and no-ops)."
  echo "  Most likely causes: no network during the build, or upstream stopped publishing"
  echo "  a manylinux wheel for this interpreter. bookworm is Python 3.11 and glibc 2.36;"
  echo "  mediapipe 1.0.0 ships py3-none-manylinux_2_28_x86_64, which fits. Check"
  echo "  https://pypi.org/project/mediapipe/#files if that changes."
  exit 0
fi

if ! curl -fsSL -o "$MODEL" "$MODEL_URL"; then
  echo "1100-gesture-control: WARNING — could not download the hand-landmarker model."
  echo "  Fetch it by hand onto the booted machine and gesture control starts working:"
  echo "    sudo curl -fsSL -o ${MODEL} \\"
  echo "      '${MODEL_URL}'"
  echo "  gesture_pointer.py exits cleanly while the file is missing."
  exit 0
fi

chown -R root:root /opt/gesture-control
chmod 0644 "$MODEL"

echo "1100-gesture-control: installed. The camera stays OFF until \"enabled\" is set to"
echo "  true in /var/lib/thinclient-agent/gesture-config.json on the booted machine."