setup.sh

#!/usr/bin/env bash

setup_script_path() {
  if [ -n "${ZSH_VERSION:-}" ]; then
    printf '%s\n' "${(%):-%x}"
    return
  fi
  if [ -n "${BASH_VERSION:-}" ]; then
    printf '%s\n' "${BASH_SOURCE[0]}"
    return
  fi
  printf '%s\n' "$0"
}

if ! (return 0 2>/dev/null); then
  printf '[setup] error: run this script via source, not as an executable\n' >&2
  printf '[setup]   source "%s"\n' "$(setup_script_path)" >&2
  exit 1
fi

ROOT_DIR="$(cd "$(dirname "$(setup_script_path)")" && pwd)"
VENV_DIR="${VENV_DIR:-$ROOT_DIR/.venv}"
PYTHON_BIN="${PYTHON_BIN:-python3}"
INSTALL_SYSTEM_DEPS="${INSTALL_SYSTEM_DEPS:-auto}"
DISTRO_FAMILY=""

log() {
  printf '[setup] %s\n' "$1"
}

warn() {
  printf '[setup] warning: %s\n' "$1" >&2
}

die() {
  printf '[setup] error: %s\n' "$1" >&2
  return 1
}

has_command() {
  command -v "$1" >/dev/null 2>&1
}

detect_distro_family() {
  if [ -z "${DISTRO_FAMILY:-}" ] && [ -f /etc/os-release ]; then
    # shellcheck disable=SC1091
    . /etc/os-release
    local distro_id="${ID:-}"
    local distro_like="${ID_LIKE:-}"
    case " $distro_id $distro_like " in
      *" debian "*|*" ubuntu "*) DISTRO_FAMILY="debian" ;;
      *" fedora "*|*" rhel "*|*" rocky "*|*" almalinux "*|*" centos "*) DISTRO_FAMILY="fedora" ;;
      *" arch "*|*" archlinux "*|*" manjaro "*) DISTRO_FAMILY="arch" ;;
      *) DISTRO_FAMILY="unknown" ;;
    esac
  fi
  printf '%s\n' "${DISTRO_FAMILY:-unknown}"
}

run_privileged() {
  if [ "$(id -u)" -eq 0 ]; then
    "$@"
    return
  fi
  if has_command sudo; then
    sudo "$@"
    return
  fi
  die "sudo is required to install system packages"
}

cleanup_project_artifacts() {
  log "Removing build and cache artifacts"
  find "$ROOT_DIR" \
    \( -path "$ROOT_DIR/.git" -o -path "$VENV_DIR" \) -prune -o \
    \( -type d \( -name "__pycache__" -o -name ".pytest_cache" -o -name ".mypy_cache" -o -name ".ruff_cache" -o -name "*.egg-info" \) -exec rm -rf {} + \)
  rm -rf "$ROOT_DIR/build" "$ROOT_DIR/dist"
}

install_system_deps() {
  if [ "$INSTALL_SYSTEM_DEPS" = "0" ] || [ "$INSTALL_SYSTEM_DEPS" = "false" ]; then
    log "Skipping system packages by request"
    return
  fi
  local family
  family="$(detect_distro_family)"
  log "Installing system packages"
  case "$family" in
    debian)
      run_privileged apt-get update
      run_privileged apt-get install -y \
        ca-certificates \
        python3 \
        python3-venv
      ;;
    fedora)
      run_privileged dnf install -y \
        ca-certificates \
        python3
      ;;
    arch)
      run_privileged pacman -Sy --noconfirm \
        ca-certificates \
        python
      ;;
    *)
      if [ "$INSTALL_SYSTEM_DEPS" = "auto" ]; then
        warn "Unsupported distro for automatic package install: ${ID:-unknown}"
        return
      fi
      die "Unsupported distro for automatic package install: ${ID:-unknown}"
      ;;
  esac
}

ensure_python() {
  has_command "$PYTHON_BIN" || die "Python interpreter not found: $PYTHON_BIN"
  "$PYTHON_BIN" - <<'PY'
import sys
raise SystemExit(0 if sys.version_info >= (3, 11) else 1)
PY
}

ensure_venv() {
  if [ ! -d "$VENV_DIR" ]; then
    log "Creating virtual environment at $VENV_DIR"
    "$PYTHON_BIN" -m venv "$VENV_DIR"
  else
    log "Using existing virtual environment at $VENV_DIR"
  fi
}

install_project() {
  log "Upgrading packaging tools"
  PIP_NO_CACHE_DIR=1 "$VENV_DIR/bin/python" -m pip install --upgrade pip setuptools wheel
  log "Installing project in editable mode"
  PIP_NO_CACHE_DIR=1 "$VENV_DIR/bin/python" -m pip install -e "$ROOT_DIR" --no-build-isolation
}

verify_installation() {
  log "Verifying installed entrypoint"
  "$VENV_DIR/bin/python" -c "from bootstrap import build_container; build_container()" >/dev/null
}

activate_venv() {
  if [ ! -f "$VENV_DIR/bin/activate" ]; then
    die "virtual environment activation script not found: $VENV_DIR/bin/activate"
  fi
  # shellcheck disable=SC1090
  . "$VENV_DIR/bin/activate"
  hash -r 2>/dev/null || true
  log "Virtual environment is active: $VENV_DIR"
}

setup_pipeline() {
  set -euo pipefail
  cd "$ROOT_DIR"
  cleanup_project_artifacts
  install_system_deps
  ensure_python
  ensure_venv
  install_project
  verify_installation
}

main() {
  (set -euo pipefail; setup_pipeline "$@")
  activate_venv
}

main "$@"