#!/bin/bash

# Copyright 2021 Google Inc. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# Builds debug-<board>-package-info.json which contains debug
# information of the packages available as part of a board.
# The script should be used from inside the chroot as it
# uses cros_sdk dependencies for extracting package information.

set -eu
set -o pipefail

PROG_NAME=$(basename "$0")
readonly PROG_NAME
BOARD=""
BUILD_ID=""
OUTPUT_DIR=""
TMP_DIR=""

cleanup_dir() {
  if [[ -d "${TMP_DIR}" ]]; then
    rm -fr "${TMP_DIR}"
  fi
}

# Returns the overlay of the package name provided.
# Example:
#   Input: sys-apps/systemd-248.6
#   Output: portage-stable
find_overlay() {
  local -r file_path=$(equery-"${BOARD}" w "${1}")
  # Split the ebuild path of the package based on '/'.
  IFS="/" read -r -a arr <<< "${file_path}"
  # Return the overlay of the package.
  # It should be the fourth element from the end.
  if [[ "${#arr[@]}" -le 4 ]]; then
    echo ""
  else
    echo "${arr[-4]}"
  fi
}

# Returns the set use_flags for the package name provided.
# Example:
#   Input: sys-apps/systemd-248.6
#   Output: +apparmor,+audit,+cgroup-hybrid,+gcrypt,+hwdb,+kmod,+lz4,
#   +networkd-wait-online,+pam,+resolvconf,+seccomp,+sysv-utils,+vanilla
find_use_flags() {
  local -r use_flags=$(equery-"${BOARD}" u "${1}" | cut -f 2-3)
  result=""

  # Looping over the use_flags.
  for val in ${use_flags}; do
    # Only include the use_flags which are set.
    if [[ "${val::1}" == "+" ]]; then
      if [[ "${result}" == "" ]]; then
        result=${val}
      else
        result+=",${val}"
      fi
    fi
  done
  echo "${result}"
}

write_debug_package_info() {
  local -r pkg_info_file=$1
  local -r output_file=$2
  local -r tmp_overlay_file=$3
  local -r tmp_use_flags_file=$4

  while IFS= read -r line; do
    # Check for empty line and comment.
    [[ -z "${line}" || "${line}" =~ ^#.* ]] && continue
    find_overlay "${line}" > "${tmp_overlay_file}" &
    find_use_flags "${line}" > "${tmp_use_flags_file}" &
    wait

    overlay=$(<"${tmp_overlay_file}")
    use_flags=$(<"${tmp_use_flags_file}")

    output="${line}"
    if [[ "${overlay}" != "" ]]; then
      output+=" overlay:${overlay}"
    fi
    if [[ "${use_flags}" != "" ]]; then
      output+=" use_flags:${use_flags}"
    fi
    echo "${output}" >> "${output_file}"
  done < "${pkg_info_file}"
}

build_debug_package_info() {
  trap cleanup_dir EXIT
  echo "Generating debug-cos-package-info.json. It may take couple of minutes.."
  TMP_DIR="$(mktemp -d -p /tmp package-list.XXXXXXXXXX)"

  local -r pkg_deps_file="${TMP_DIR}"/pkg_deps.txt
  local -r pkg_info_file="${TMP_DIR}"/pkg_info.txt
  local -r debug_pkg_info_file="${TMP_DIR}"/debug_pkg_info.txt
  local -r tmp_overlay_file="${TMP_DIR}"/overlay.txt
  local -r tmp_use_flags_file="${TMP_DIR}"/use_flags.txt

  # Generate the package dependency file.
  # The generated file will contain snippet
  # similar to below:
  #
  # {
  #   "acct-group/docker-0.0.1": {
  #   "action": "merge",
  #   "category": "acct-group",
  #   "cpes": [],
  #   "deps": [
  #     "sys-apps/baselayout-2.2-r1"
  #    ],
  #   "full_name": "acct-group/docker-0.0.1",
  #   "name": "docker",
  #   "rev_deps": [
  #     "app-emulation/docker-20.10.6-r5"
  #    ],
  #   "version": "0.0.1"
  # }
  (cros_extract_deps \
    --sysroot /build/"${BOARD}" \
    --format deps \
    virtual/target-os \
    --output-path "${pkg_deps_file}")

  # Extract the package name from the
  # above generated file.
  # Output:
  #  acct-group/docker-0.0.1
  ( grep "full_name" <"${pkg_deps_file}" \
    | awk -F '"' '{print $4}' >> "${pkg_info_file}")

  write_debug_package_info \
    "${pkg_info_file}" \
    "${debug_pkg_info_file}" \
    "${tmp_overlay_file}" \
    "${tmp_use_flags_file}"

  local -r script_root="$(readlink -f "$(dirname "${BASH_SOURCE[0]}")")"
  sudo "${script_root}/create_pkg_info.py" \
      --input="allPackages:${debug_pkg_info_file}" \
      --output="${OUTPUT_DIR}/debug-${BOARD}-package-info.json" \
      --build-id="${BUILD_ID}" \
      --debug

  cleanup_dir
  trap - EXIT
}

usage() {
  local exit_code="${1}"

  cat <<EOF
Usage:
   ${PROG_NAME} -b <board> -i <build_id> -o <output_dir>
  -b, --board        board for which file should be created
  -i, --build_id     build_id to be used in the debug-<board>-package-info.json
  -o, --output_dir   Output directory where file will be created

Examples:
        $ ${PROG_NAME} \
        -b lakitu \
        -i 1.0.0 \
        -o /mnt/host/source/src/build/images/lakitu/1.0.0
EOF
  exit "${exit_code}"
}

# Parse command line arguments.
parse_args() {
  local args
  if ! args=$(getopt \
               --options "b:i:o:" \
               --longoptions "board: build_id: output_dir:" \
               -- "$@"); then
      usage 1
  fi
  eval set -- "${args}"

  while :; do
    arg="${1}"
    shift
    case "${arg}" in
      -b|--board)
          BOARD="${1}"; shift ;;
      -i|--build_id)
          BUILD_ID="${1}"; shift ;;
      -o|--output_dir)
          OUTPUT_DIR="${1}"; shift ;;
      --)
          break ;;
      *)
          echo "internal error parsing arguments!"; usage 1 ;;
      esac
  done

  if [[ -z "${BOARD}" ||
        -z "${BUILD_ID}" ||
        -z "${OUTPUT_DIR}" ]]; then
      usage 1
  fi
}

main() {
  parse_args "$@"
  build_debug_package_info
}

main "$@"