#!/usr/bin/env bash
# 
# dagpkg - create a directed graph of package dependencies and build
#          them in topological order
# 
# (c) 2014  Nicolás Reynolds <fauno@parabola.nu>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
set -e

# Source variables from libretools
source /etc/libretools.conf
source $XDG_CONFIG_HOME/libretools/libretools.conf &>/dev/null || true

# Source variables from makepkg
source /etc/makepkg.conf
source $XDG_CONFIG_HOME/.makepkg.conf &>/dev/null || true

# End inmediately but print an useful message
trap_exit() {
  term_title "error!"
  test ${depth} -eq 0 &&
  error "(%s) %s (leftovers on %s)" \
        "${0##*/}" "$@" "${temp_dir}"
  exit 1
}

# Trap signals from makepkg
trap 'trap_exit "TERM signal caught. Exiting..."' TERM HUP QUIT
trap 'trap_exit "Aborted by user! Exiting..."' INT
trap 'trap_exit "An unknown error has occurred. Exiting..."' ERR

# Source this PKGBUILD, if it doesn't exist, exit
if ! source PKGBUILD &>/dev/null ; then
 error "No PKGBUILD in %s" "$PWD"
 exit 1
fi

# Save resources
unset pkgdesc arch license groups backup install md5sums sha1sums \
      sha256sums source options &>/dev/null

unset build package &>/dev/null

for _pkg in ${pkgname[@]}; do
  unset package_${_pkg} &>/dev/null || true
done

# This is the name of the package
name="${pkgbase:-${pkgname[0]}}"

# The name of the previous package
prev="${3}"
depth="${2:-0}"
let next=${depth}+1 || true

# A temporary work dir and log file
temp_dir="${1:-$(mktemp -d /tmp/${name}-testpkg-XXXX)}"
log="${temp_dir}/buildorder"

# Generate the full version with epoch
get_fullver() {
    if [ $1 -eq 0 ]; then
# zero epoch case, don't include it in version
        echo $2-$3
    else
        echo $1:$2-$3
    fi

}

# If it's already built we don't bother
is_built ${pkgname[0]} $(get_fullver ${epoch:-0} ${pkgver} ${pkgrel}) &&
exit

echo "${arch[@]}" | grep -qw "$CARCH" || warning "%s isn't ported to %s yet" ${name} ${CARCH}

# If the envvar I contains this package, ignore it and exit
echo "$I" | grep -qw "$name" &&
msg2 "%s ignored" ${name} &&
exit

msg "%s (%s)" ${name} ${prev}

build=false
if [ ! -z "${1}" -a ${depth} -eq 0 ]; then
  build=true
fi

# If we specified a work dir on the cli it means we want to skip
# dependency graph creation and jump to build whatever is there
if ! ${build}; then

  # Export a pair of current and previous package to get a list of graph
  # edges
  echo -e "${name}\t${prev:--}" >>${log}

  # Infinite loop detection, if the inverted pair current+prev was
  # already seen, skip
  if grep -q "${prev}[[:space:]]${name}" ${log} ; then
    msg2 "infinite loop %s<->%s" $name $prev
    exit
  fi

  # Recurse into dependencies
  for d in ${depends[@]} ${makedepends[@]}; do
    # Cleanup dependency versions
    d=$(echo $d | sed "s/[<>=].*//")

    # Where's the pkgbuild?
    w=$(toru-where $d)

    # Skip if not available
    test -z "$w" && continue

    # revisited edge detection
    # we use the basename of the package dir as pkgbase to avoid
    # recalling an edge using one of the other pkgname's
    if grep -q "^${w##*/}[[:space:]]" ${log} ; then
      msg2 "edge %s already visited" ${d}
      # add edge anyway but avoid reprocessing
      echo -e "${w##*/}\t${name}" >>${log}
      continue
    fi

    # Go to this dir
    pushd $w &>/dev/null

    # Run this same command giving work dir, depth and previous package
    $0 ${temp_dir} ${next} ${name}

    popd &>/dev/null
  done
else
  msg "Resuming build..."
fi

# end here if we're not the first package
test ${depth} -ne 0 && exit

# enter work dir
pushd "${temp_dir}" &>/dev/null
# TODO do something when loops are discovered (fail? skip?)
tsort ${log} | head -n-1 | tac | nl | tac | while read order pkg; do
  # skip if already built
  test -f "${pkg}/built_ok" && continue

  # where's this package?
  w="$(toru-where "$pkg")"
  test -z "$w" && continue

  # copy to work dir if not already
  # this means you can make modifications to the pkgbuild during the
  # graph build or remove the dir after a build failure and let dagpkg
  # copy a new version
  test -d "$pkg" || cp -r "$w" "$pkg"
  pushd "$pkg" &>/dev/null

  term_title "$pkg($order)"

  msg "Building %s" ${pkg}

  # upgrade the system
  # this would probably have to go on HOOKPREBUILD if you're working
  # outside chroots
  sudo -E pacman -Syu --noconfirm

  # run the pre build command from libretools.conf
  ${HOOKPREBUILD}

  # run the build command
  ${FULLBUILDCMD}

  # Run local release hook with $1 = $repo
  ${HOOKLOCALRELEASE} "$(basename "$(dirname "$w")")"

  # it's built!
  touch built_ok

  popd &>/dev/null
done

popd &>/dev/null
# cleanup
rm -rf ${log} "${temp_dir}"

term_title "done"