#!/usr/bin/env bash
set -euo pipefail

PROJECT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
PYTHON_BIN="${PYTHON_BIN:-python3.12}"
VENV_DIR="${PROJECT_DIR}/.venv"
WHEELHOUSE_DIR="${PROJECT_DIR}/wheelhouse"
LOCK_FILE="${PROJECT_DIR}/requirements.lock.txt"
WEIGHTS_FILE="${PROJECT_DIR}/weights/yolo11n.pt"
RUN_SCRIPT="${PROJECT_DIR}/scripts/run.sh"
INSTALL_SERVICE_SCRIPT="${PROJECT_DIR}/scripts/install_service.sh"
PROJECT_USER="${SUDO_USER:-$(id -un)}"

run_privileged() {
  if [[ "$(id -u)" -eq 0 ]]; then
    "$@"
    return
  fi
  sudo "$@"
}

run_project_user() {
  if [[ "$(id -u)" -eq 0 && -n "${SUDO_USER:-}" ]]; then
    sudo -u "${PROJECT_USER}" -H "$@"
    return
  fi
  "$@"
}

ensure_system_package() {
  local command_name="$1"
  local package_name="$2"
  if command -v "${command_name}" >/dev/null 2>&1; then
    return
  fi

  echo "Installing missing package: ${package_name}"
  run_privileged apt-get -o Acquire::ForceIPv4=true update
  run_privileged apt-get -o Acquire::ForceIPv4=true install -y "${package_name}"
}

require_file() {
  local target="$1"
  if [[ ! -e "${target}" ]]; then
    echo "Missing required file: ${target}" >&2
    exit 1
  fi
}

if ! command -v "${PYTHON_BIN}" >/dev/null 2>&1; then
  echo "Python interpreter not found: ${PYTHON_BIN}" >&2
  echo "Set PYTHON_BIN=/path/to/python3.12 if needed." >&2
  exit 1
fi

ensure_system_package ffmpeg ffmpeg

if [[ ! -d "/usr/lib/python3.12/venv" && ! -d "/usr/lib/python3.12/ensurepip" ]]; then
  echo "Installing missing package: python3.12-venv"
  run_privileged apt-get -o Acquire::ForceIPv4=true update
  run_privileged apt-get -o Acquire::ForceIPv4=true install -y python3.12-venv
fi

if ! command -v nvidia-smi >/dev/null 2>&1; then
  echo "nvidia-smi is required but not installed." >&2
  exit 1
fi

require_file "${LOCK_FILE}"
require_file "${WEIGHTS_FILE}"
require_file "${RUN_SCRIPT}"
require_file "${INSTALL_SERVICE_SCRIPT}"

if [[ ! -d "${WHEELHOUSE_DIR}" ]]; then
  echo "Missing wheelhouse directory: ${WHEELHOUSE_DIR}" >&2
  exit 1
fi

run_project_user "${PYTHON_BIN}" -m venv "${VENV_DIR}"
run_project_user "${VENV_DIR}/bin/python" -m ensurepip --upgrade
while IFS= read -r requirement; do
  if [[ -z "${requirement}" ]]; then
    continue
  fi
  run_project_user "${VENV_DIR}/bin/python" -m pip install \
    --no-index \
    --no-deps \
    --find-links "${WHEELHOUSE_DIR}" \
    "${requirement}"
done < "${LOCK_FILE}"

mkdir -p \
  "${PROJECT_DIR}/config" \
  "${PROJECT_DIR}/data/runtime" \
  "${PROJECT_DIR}/data/staff_gallery" \
  "${PROJECT_DIR}/logs"

run_project_user bash "${RUN_SCRIPT}" --prepare-only
bash "${INSTALL_SERVICE_SCRIPT}"
run_privileged systemctl enable --now store-dwell-alert.service

cat <<EOF
Offline install complete.
Service started and enabled on boot: store-dwell-alert.service
Runtime log: ${PROJECT_DIR}/logs/runtime.log
Event sink: ${PROJECT_DIR}/logs/events.jsonl
EOF