#!/bin/sh

# receive one package to be built from the build-list whose dependencies
# are already satisfied or which breaks a dependency cycle
# accepts a comma separated list of prefered packages as the first argument

# exit code shows state of success:
#  0: ok, I gave you an assignment
#  1: come back (shortly) later - I was running already
#  2: come back later - there are still packages to be built,
#     but currently none has all its dependencies ready
#  3: come back after the next run of get-package-updates - currently
#     there are no pending packages

# shellcheck source=conf/default.conf
. "${0%/*}/../conf/default.conf"

mkdir -p "${work_dir}/package-states"

hand_out_assignment() {

  # find out the sub_pkgrel
  sub_pkgrel=$(
    next_sub_pkgrel "$1" "$2" "$3" "$4"
  )

  # we don't care anymore if an older version of this package was
  # "locked" or "broken"
  find "${work_dir}/package-states" -maxdepth 1 -regextype grep \
    -regex '.*/'"$(str_to_regex "$1")"'\(\.[^.]\+\)\{3\}\.\(locked\|broken\)' \
    -not -regex '.*/'"$(str_to_regex "$1.$2.$3.$4.")"'[^.]\+' \
    -delete

  # move that build order to the end of the build-list
  sed -i '
    /^'"$(str_to_regex "$1 $2 $3 $4")"'$/ {
      $ b
      d
    }
    $ a '"$1 $2 $3 $4" \
    "${work_dir}/build-list"

  echo "$1 $2 $3 $4 ${sub_pkgrel}"
  {
    # shellcheck disable=SC2154
    echo "${slave}"
    if [ -r "${work_dir}/package-states/$1.$2.$3.$4.locked" ]; then
      cat "${work_dir}/package-states/$1.$2.$3.$4.locked"
    fi
  } | \
    sort -u | \
    sponge "${work_dir}/package-states/$1.$2.$3.$4.locked"
  # shellcheck disable=SC2016
  {
    printf 'UPDATE `build_slaves`'
    printf ' SET `currently_building` = ('
    printf ' SELECT `build_assignments`.`id`'
    printf ' FROM `build_assignments`'
    printf ' JOIN `package_sources` ON `build_assignments`.`package_source`=`package_sources`.`id`'
    printf ' JOIN `upstream_repositories` ON `package_sources`.`upstream_package_repository`=`upstream_repositories`.`id`'
    printf ' WHERE'
    printf ' `package_sources`.`%s` = from_base64("%s") AND' \
      'pkgbase'          "$(printf '%s' "$1" | base64 -w0)" \
      'git_revision'     "$(printf '%s' "$2" | base64 -w0)" \
      'mod_git_revision' "$(printf '%s' "$3" | base64 -w0)"
    printf ' `upstream_repositories`.`name` = from_base64("%s")' \
      "$(printf '%s' "$4" | base64 -w0)"
    printf ')'
    printf ' WHERE `build_slaves`.`name`=from_base64("%s");' \
      "$(printf '%s' "${slave}" | base64 -w0)"
  } | \
    ${mysql_command}

  # lock every loop this package breaks
  find "${work_dir}/build-list.loops" -maxdepth 1 -regextype grep \
    -regex '.*/loop_[0-9]\+' \
    -exec grep -qxF "$1" '{}' \; \
    -exec touch '{}.locked' \;

  exit 0

}

if [ -s "${work_dir}/build-master-sanity" ]; then
  >&2 echo 'Build master is not sane.'
  exit 1
fi

# Create a lock file and a trap.

exec 9> "${build_list_lock_file}"
if ! flock -n 9; then
  >&2 echo 'come back (shortly) later - I cannot lock build list.'
  exit 1
fi

exec 8> "${sanity_check_lock_file}"
if ! flock -s -n 8; then
  >&2 echo 'come back (shortly) later - sanity-check running.'
  exit 1
fi

clean_up() {
  rm -f "${build_list_lock_file}"
  rm -rf --one-file-system "${tmp_dir}"
}

tmp_dir=$(mktemp -d 'tmp.get-assignment.XXXXXXXXXX' --tmpdir)
trap clean_up EXIT

# Check if there are any pending packages at all and if the requester
# has already got an assignment.

pending_packages=false

while read -r package git_revision mod_git_revision repository; do

  generate_package_metadata "${package}.${git_revision}.${mod_git_revision}.${repository}"

  if [ -f "${work_dir}/package-states/${package}.${git_revision}.${mod_git_revision}.${repository}.locked" ]; then
    # has this slave already got or does he prefer this assignment?
    # note, that the dependencies are met, because this package is already locked
    if grep -qxF "${slave}" "${work_dir}/package-states/${package}.${git_revision}.${mod_git_revision}.${repository}.locked" || \
      printf ',%s,' "$1" | \
        grep -qF ",${package},"; then
      hand_out_assignment "${package}" "${git_revision}" "${mod_git_revision}" "${repository}"
    fi
  elif [ ! -f "${work_dir}/package-states/${package}.${git_revision}.${mod_git_revision}.${repository}.blocked" ]; then
    pending_packages=true
  fi

done < "${work_dir}/build-list"

if ! ${pending_packages}; then
  >&2 echo 'come back after the next run of get-package-updates - currently there are no pending packages'
  exit 3
fi

# Find first package of build-list whose "dependencies" are all met
# 1st: prefered packages on the build list which have all dependencies met
# 2nd: unbroken packages on the build list which have all dependencies met
# 3rd: unbroken packages breaking a loop
# 4th: broken packages which have all dependencies met or break a loop

for iteration in 'prefered' 'fresh' 'loops' 'broken'; do

  case "${iteration}" in
    'prefered')
      hand_out_blocked=true
      hand_out_broken=true
      hand_out_loop=false
      echo "$1" | \
        tr ',' '\n' | \
        sort -u > \
        "${tmp_dir}/hand-out-only-these-packages"
    ;;
    'fresh')
      hand_out_blocked=false
      hand_out_broken=false
      hand_out_loop=false
      {
        cat "${work_dir}/build-list"
        find "${work_dir}/package-states" -name '*.broken' -printf '%f\n' | \
          sed '
            s|\.\([^.]\+\)\.\([^.]\+\)\.\([^.]\+\)\.[^.]\+$| \1 \2 \3|
            p
          '
      } | \
        sort -k1,1 -k2 | \
        uniq -u | \
        cut -d' ' -f1 | \
        uniq > \
        "${tmp_dir}/hand-out-only-these-packages"
    ;;
    'loops')
      hand_out_blocked=false
      hand_out_broken=false
      hand_out_loop=true
      find "${work_dir}/build-list.loops" -maxdepth 1 -regextype grep \
        -regex '.*/loop_[0-9]\+' \
        -exec cat {} \; | \
        sort -u > \
        "${tmp_dir}/hand-out-only-these-packages"
    ;;
    'broken')
      hand_out_blocked=false
      hand_out_broken=true
      hand_out_loop=true
      cut -d' ' -f1 < \
        "${work_dir}/build-list" | \
        sort -u > \
        "${tmp_dir}/hand-out-only-these-packages"
    ;;
  esac

  cat -n "${work_dir}/build-list" | \
    sort -k2,2 | \
    join -1 1 -2 2 -o 2.1,2.2,2.3,2.4,2.5 "${tmp_dir}/hand-out-only-these-packages" - | \
    sort -k1,1 | \
    sed 's|^\s*\S\+\s\+||' > \
    "${tmp_dir}/try-to-hand-out-these-packages"

  while read -r package git_revision mod_git_revision repository; do

    # package locked? (we have taken care of those in the previous loop)
    if [ -f "${work_dir}/package-states/${package}.${git_revision}.${mod_git_revision}.${repository}.locked" ]; then
      continue
    fi

    # package blocked?
    if ! ${hand_out_blocked} &&
      [ -f "${work_dir}/package-states/${package}.${git_revision}.${mod_git_revision}.${repository}.blocked" ]; then
      continue
    fi

    # package broken?
    if ! ${hand_out_broken} && \
      [ -f "${work_dir}/package-states/${package}.${git_revision}.${mod_git_revision}.${repository}.broken" ]; then
      continue
    fi

    # dependencies met?
    if [ -n "$(find_dependencies_on_build_list "${package}" "${git_revision}" "${mod_git_revision}" "${repository}")" ]; then
      # do we hand out looped packages?
      if ! ${hand_out_loop}; then
        continue
      fi
      # is it a looped package?
      if ! find "${work_dir}/build-list.loops" -maxdepth 1 -regextype grep \
        -regex '.*/loop_[0-9]\+' \
        -exec cat {} \; | \
        grep -qxF "${package}"; then
        continue
      fi
    fi

    hand_out_assignment "${package}" "${git_revision}" "${mod_git_revision}" "${repository}"

  done < \
    "${tmp_dir}/try-to-hand-out-these-packages"

done

# Remove the lock file

>&2 echo 'come back later - there are still packages to be built, but currently none has all its dependencies ready'
exit 2