#!/bin/sh
set -e

cd "$(dirname "$0")/.."
INSTALL_DIR="$(pwd)"
SERVICE_USER="${SERVICE_USER:-${SUDO_USER:-$USER}}"
VENV_PYTHON="$INSTALL_DIR/.venv/bin/python"

if [ "$SERVICE_USER" = "root" ] || [ -z "$SERVICE_USER" ]; then
    echo "Set SERVICE_USER or run via sudo as your normal user." >&2
    exit 1
fi

if ! getent group patlite >/dev/null; then
    echo "Group 'patlite' not found. Run ./scripts/install-udev.sh first." >&2
    exit 1
fi

if ! id -nG "$SERVICE_USER" | tr ' ' '\n' | grep -qx patlite; then
    echo "Warning: user '$SERVICE_USER' is not in group 'patlite' (USB access may fail)." >&2
    echo "Run: sudo usermod -aG patlite $SERVICE_USER" >&2
fi

if ! command -v python3 >/dev/null; then
    echo "python3 is required." >&2
    exit 1
fi

if ! ldconfig -p 2>/dev/null | grep -q 'libusb-1.0\.so'; then
    echo "Warning: libusb-1.0 may be missing. Install: sudo apt install libusb-1.0-0" >&2
fi

if ! python3 -c "import venv" 2>/dev/null; then
    echo "python3-venv is required. Install with: sudo apt install python3-venv" >&2
    exit 1
fi

if [ ! -x .venv/bin/python ]; then
    python3 -m venv .venv
fi

if ! .venv/bin/python -m pip --version >/dev/null 2>&1; then
    if ! .venv/bin/python -m ensurepip --upgrade >/dev/null 2>&1; then
        echo "pip is missing from the venv. Install with:" >&2
        echo "  sudo apt install python3-venv python3-pip" >&2
        exit 1
    fi
fi

.venv/bin/python -m pip install -q -U pip
.venv/bin/python -m pip install -q -r requirements.txt

sudo mkdir -p /etc/patlite-mqtt
if [ ! -f /etc/patlite-mqtt/patlite-mqtt.env ]; then
    sudo install -m 640 systemd/patlite-mqtt.env.example /etc/patlite-mqtt/patlite-mqtt.env
    sudo chown root:"$SERVICE_USER" /etc/patlite-mqtt/patlite-mqtt.env
    echo "Created /etc/patlite-mqtt/patlite-mqtt.env — edit MQTT settings before starting."
else
    echo "Keeping existing /etc/patlite-mqtt/patlite-mqtt.env"
fi

sed \
    -e "s|@INSTALL_DIR@|$INSTALL_DIR|g" \
    -e "s|@VENV_PYTHON@|$VENV_PYTHON|g" \
    -e "s|@SERVICE_USER@|$SERVICE_USER|g" \
    systemd/patlite-mqtt.service.in | sudo tee /etc/systemd/system/patlite-mqtt.service >/dev/null

sudo systemctl daemon-reload
sudo systemctl enable patlite-mqtt.service

echo ""
echo "Installed patlite-mqtt.service"
echo "  Install dir:  $INSTALL_DIR"
echo "  Service user: $SERVICE_USER"
echo "  Config:       /etc/patlite-mqtt/patlite-mqtt.env"
echo ""
echo "Edit config, then:"
echo "  sudo systemctl restart patlite-mqtt"
echo "  sudo systemctl status patlite-mqtt"
echo "  journalctl -u patlite-mqtt -n 30 --no-pager"