#!/bin/bash

# Copyright 2016 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

SCRIPT_ROOT=$(dirname $(readlink -f "$0"))
. "${SCRIPT_ROOT}/build_library/build_common.sh" || exit 1

DEFINE_string board "${DEFAULT_BOARD}" \
  "The board to build an image for."
DEFINE_string package "" \
  "Package whose bare minimum deps the final container should have."
DEFINE_string extra "" \
  "Comma separated extra packages to be included in the final image."

FLAGS "$@" || exit 1
eval set -- "${FLAGS_ARGV}"
switch_to_strict_mode

# Produce the container image.
build_container_image() {
  local pkg_name="$1"
  local ROOTDIR="out"

  info "Cleaning previously generated files ... "
  sudo rm -rf "${ROOTDIR}"

  install_with_root_deps "${pkg_name}" "${ROOTDIR}"

  local pkg
  for pkg in $(echo $FLAGS_extra | sed "s/,/ /g"); do
    install_with_root_deps "${pkg}" "${ROOTDIR}"
  done

  info "Installing libc.so ... "
  install_libc "${ROOTDIR}"

  info "Installing libcontainer_overrides ... "
  install_with_no_deps "chromeos-base/libcontainer_overrides" "${ROOTDIR}"

  info "Creating top level dirs and socket dirs ... "
  sudo mkdir -p "${ROOTDIR}"/{dev,proc,root,run/broker_service,sys}

  info "Generating squashfs file ... "
  mksquashfs "${ROOTDIR}" "${pkg_name}.sqsh"

  info "Cleaning up ... "
  sudo rm -rf "${ROOTDIR}"
}

# Normal emerge.
install_with_no_deps() {
  local package_to_install="$1"
  local root_dir="$2"
  info "Installing '${package_to_install}' with no deps ... "
  emerge-${BOARD} "${package_to_install}" --nodeps --usepkgonly \
    --root="${root_dir}" --quiet
}

# Emerge with root deps.
install_with_root_deps() {
  local package_to_install="$1"
  local root_dir="$2"
  info "Installing '${package_to_install}' with root deps ... "
  emerge-${BOARD} "${package_to_install}" --root-deps=rdeps --usepkgonly \
    --root="${root_dir}" --quiet
}

main() {
  . "${BUILD_LIBRARY_DIR}/board_options.sh" || exit 1
  . "${BUILD_LIBRARY_DIR}/base_image_util.sh" || exit 1

  if [[ -n "${FLAGS_package}" ]]; then
    if [[ -f "${FLAGS_package}.sqsh" ]]; then
      die_notrace "File already exists : ${FLAGS_package}.sqsh"
    fi
    info "Building container for ${FLAGS_package} ..."
    build_container_image "${FLAGS_package}"
  else
    die_notrace "--package is needed."
  fi
}

main "$@"