#!/bin/bash
# Copyright (c) 2024 The Flatcar Maintainers.
# Distributed under the terms of the GNU General Public License v2

. "${0%/*}"/common.sh || exit 1

DEFINE_string board "${DEFAULT_BOARD}" \
  "The board to set package keywords for."
DEFINE_boolean host "${FLAGS_FALSE}" \
  "Uses the host instead of board"

FLAGS_HELP="usage: $0 <command> [flags] <atom>
commands:
  start:  Moves an ebuild to live (intended to support development)
  stop:   Moves an ebuild to stable (use last known good)
  list:   List of live ebuilds"
FLAGS "$@" || { [[ ${FLAGS_help} = "${FLAGS_TRUE}" ]] && exit 0; } || exit 1
eval set -- "${FLAGS_ARGV}"

set -euo pipefail

# If both board and host are specified, just use host, because board
# does not have to be specified and may come from default, in which
# case there's no way to override.
if [[ -n ${FLAGS_board} && ${FLAGS_host} = "${FLAGS_TRUE}" ]]; then
  unset FLAGS_board # kill board
fi

# /etc/portage under either / or /build/<board>.
ETC_PORTAGE=${FLAGS_board+/build/${FLAGS_board}}/etc/portage

# If the board dir doesn't exist yet, we don't want to create it as that'll
# screw up ./setup_board later on.
[[ -d ${ETC_PORTAGE} ]] ||
  die "${FLAGS_board} has not been setup yet"

find_ebuild() {
  if [[ -z ${1-} ]]; then
    flags_help
    exit 1
  fi

  # Exact atom does not need to be given. Resolve to an ebuild with equery.
  EBUILD=$(equery which --include-masked "$1")

  [[ -n ${EBUILD} ]] ||
    die "Package matching \"$1\" could not be found."

  PN=${EBUILD%/*}
  PN=${PN##*/}

  CAT=${EBUILD%/*/*}
  CAT=${CAT##*/}

  CP=${CAT}/${PN}
}

add_if_needed() {
  grep -Fxq "$1" "$2" 2>/dev/null || sudo tee -a "$2" >/dev/null <<< "$1"
}

start() {
  export PORTAGE_TMPDIR
  PORTAGE_TMPDIR=$(mktemp -d)
  trap 'rm -rf -- "${PORTAGE_TMPDIR}"' EXIT

  # Load the ebuild environment to reliably pull out variables.
  "ebuild${FLAGS_board+-}${FLAGS_board-}" "${EBUILD}" setup
  # shellcheck disable=SC1090
  . "${PORTAGE_TMPDIR}"/portage/*/*/temp/environment

  [[ -n ${EGIT_REPO_URI-} ]] ||
    die "${EBUILD} is not live because it does not set EGIT_REPO_URI."

  [[ -z ${EGIT_COMMIT-} ]] ||
    die "${EBUILD} is not live because it sets EGIT_COMMIT."

  ### v--- Taken from git-r3.eclass ---v

  if [[ $(declare -p EGIT_REPO_URI) == "declare -a"* ]]; then
    repos=( "${EGIT_REPO_URI[@]}" )
  else
    # shellcheck disable=SC2206
    repos=( ${EGIT_REPO_URI} )
  fi

  repo_name=${repos[0]#*://*/}

  # strip the trailing slash
  repo_name=${repo_name%/}

  # strip common prefixes to make paths more likely to match
  # e.g. git://X/Y.git vs https://X/git/Y.git
  # (but just one of the prefixes)
  case "${repo_name}" in
    # gnome.org... who else?
    browse/*) repo_name=${repo_name#browse/};;
    # cgit can proxy requests to git
    cgit/*) repo_name=${repo_name#cgit/};;
    # pretty common
    git/*) repo_name=${repo_name#git/};;
    # gentoo.org
    gitroot/*) repo_name=${repo_name#gitroot/};;
    # sourceforge
    p/*) repo_name=${repo_name#p/};;
    # kernel.org
    pub/scm/*) repo_name=${repo_name#pub/scm/};;
  esac
  # ensure a .git suffix, same reason
  repo_name=${repo_name%.git}.git
  # now replace all the slashes
  repo_name=${repo_name//\//_}

  # get the name and do some more processing:
  # 1) kill .git suffix,
  # 2) underscore (remaining) non-variable characters,
  # 3) add preceding underscore if it starts with a digit,
  # 4) uppercase.
  override_name=${repo_name##*/}
  override_name=${override_name%.git}
  override_name=${override_name//[^a-zA-Z0-9_]/_}
  override_name=${override_name^^}

  ### ^--- Taken from git-r3.eclass ---^

  GIT_WORKTREE=/home/sdk/trunk/src/scripts/workon/${repo_name}
  sudo mkdir -p "${ETC_PORTAGE}"/{env,package.accept_keywords,package.env}

  add_if_needed \
    "EGIT_OVERRIDE_REPO_${override_name}=\"${GIT_WORKTREE}\" # ${CP}" \
    "${ETC_PORTAGE}"/env/workon.conf

  add_if_needed \
    "${CP} workon.conf" \
    "${ETC_PORTAGE}"/package.env/workon.conf

  add_if_needed \
    "${CP} **" \
    "${ETC_PORTAGE}"/package.accept_keywords/workon.conf

  if [[ ! -e ${GIT_WORKTREE} ]]; then
    mkdir -p "${GIT_WORKTREE%/*}"
    git clone "${repos[0]}" "${GIT_WORKTREE}"
  fi

  return 0
}

stop() {
  [[ -e ${ETC_PORTAGE}/env/workon.conf ]] &&
    sudo sed -i "/# ${CP//\//\\/}\$/d" "${ETC_PORTAGE}"/env/workon.conf

  [[ -e ${ETC_PORTAGE}/package.accept_keywords/workon.conf ]] &&
    sudo sed -i "/^${CP//\//\\/} /d" "${ETC_PORTAGE}"/package.accept_keywords/workon.conf

  [[ -e ${ETC_PORTAGE}/package.env/workon.conf ]] &&
    sudo sed -i "/^${CP//\//\\/} /d" "${ETC_PORTAGE}"/package.env/workon.conf

  return 0
}

list() {
  [[ -e ${ETC_PORTAGE}/package.env/workon.conf ]] &&
    sed '/\bworkon\.conf\b/s:\s.*::' "${ETC_PORTAGE}"/package.env/workon.conf

  return 0
}

case "$1" in
  start)
    find_ebuild "${2-}"
    start ;;
  stop)
    find_ebuild "${2-}"
    stop ;;
  list)
    list ;;
  *)
    flags_help
    die "$0: command \"$1\" not recognized" ;;
esac