#!/bin/sh

# delete obsolete binary packages

# 1] Condition for deleting a package A is that:
#   a) nothing on the build-list (make|check|)depends on A and
#   b) no built package B which is not being deleted depends on A

# "Package x depends on package y" means, that something needed by x
# is provided by y and no other package which will not be deleted.

# shellcheck disable=SC2039
# shellcheck source=conf/default.conf
. "${0%/*}/../conf/default.conf"

# TODO: delete other to-be-deleted packages if asked to do so

# shellcheck disable=SC2016
usage() {
  >&2 echo ''
  >&2 echo 'delete-packages [options]:'
  >&2 echo ' delete obsolete binary packages.'
  >&2 echo ''
  >&2 echo 'possible options:'
  >&2 echo '  -b|--block:       If necessary, wait for lock blocking.'
  >&2 echo '  -h|--help:        Show this help and exit.'
  >&2 echo '  -n|--no-action:   Only print what would be deleted.'
  [ -z "$1" ] && exit 1 || exit "$1"
}

eval set -- "$(
  getopt -o bhn \
    --long block \
    --long help \
    --long no-action \
    -n "$(basename "$0")" -- "$@" || \
  echo usage
)"

block_flag='-n'
no_action=false

while true
do
  case "$1" in
    -b|--block)
      block_flag=''
    ;;
    -h|--help)
      usage 0
    ;;
    -n|--no-action)
      no_action=true
    ;;
    --)
      shift
      break
    ;;
    *)
      >&2 echo 'Whoops, forgot to implement option "'"$1"'" internally.'
      exit 42
    ;;
  esac
  shift
done

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

# Create a lock file and a trap.

if ! ${no_action}; then

#  exec 9> "${build_list_lock_file}"
#  if ! flock ${block_flag} 9; then
#    >&2 echo 'come back (shortly) later - I cannot lock build list.'
#    exit 0
#  fi

  exec 8> "${package_database_lock_file}"
  if ! flock ${block_flag} 8; then
    >&2 echo 'come back (shortly) later - I cannot lock package database.'
    exit 0
  fi

  exec 7> "${sanity_check_lock_file}"
  if ! flock -s ${block_flag} 7; then
    >&2 echo 'come back (shortly) later - sanity-check running.'
    exit 0
  fi

fi

tmp_dir=$(mktemp -d "${work_dir}/tmp.delete-packages.XXXXXXXXXX")
trap 'rm -rf --one-file-system "${tmp_dir}"' EXIT

# shellcheck disable=SC2016
{
  printf 'CREATE TEMPORARY TABLE `to_deletes` (`id` BIGINT, UNIQUE KEY (`id`));\n'
  printf 'INSERT IGNORE INTO `to_deletes`'
  printf ' SELECT `binary_packages`.`id`'
  printf ' FROM `binary_packages`'
  mysql_join_binary_packages_dependencies
  mysql_join_dependencies_dependency_types
  printf ' AND `dependency_types`.`relevant_for_binary_packages`'
  mysql_join_binary_packages_repositories
  printf ' AND `repositories`.`is_on_master_mirror`'
  printf ' WHERE `binary_packages`.`is_to_be_deleted`'
  printf ' AND NOT EXISTS ('
    printf 'SELECT * FROM `install_target_providers`'
    printf ' WHERE `install_target_providers`.`install_target`=`dependencies`.`depending_on`'
  printf ');\n'

  printf ' SELECT DISTINCT "repo",`repositories`.`name`'
  printf ' FROM `to_deletes`'
  printf ' JOIN `binary_packages` ON `to_deletes`.`id`=`binary_packages`.`id`'
  mysql_join_binary_packages_repositories
  printf ';\n'

  printf ' SELECT "package",`repositories`.`name`,`binary_packages`.`pkgname`'
  printf ' FROM `to_deletes`'
  printf ' JOIN `binary_packages` ON `to_deletes`.`id`=`binary_packages`.`id`'
  mysql_join_binary_packages_repositories
  printf ';\n'

  printf ' SELECT "package-id",`to_deletes`.`id`'
  printf ' FROM `to_deletes`'
  printf ';\n'
} | \
  mysql_run_query | \
  sed '
    y/\t/ /
    /^repo /{
      s/^\S\+ //
      w '"${tmp_dir}"'/repositories
      d
    }
    /^package /{
      s/^\S\+ //
      w '"${tmp_dir}"'/packages
      d
    }
    /^package-id /{
      s/^\S\+ //
      w '"${tmp_dir}"'/package-ids
      d
    }
  '

if [ ! -s "${tmp_dir}/packages" ]; then
  printf 'Nothing to delete.\n'
  exit
fi

if ${no_action}; then
  printf 'I would delete the following packages:\n'
  sed '
    y, ,/,
    s/^/  /
  ' "${tmp_dir}/packages"
  printf 'From these repositories:\n'
  sed '
    s/^/  /
  ' "${tmp_dir}/repositories"
  exit
fi

mkdir "${tmp_dir}/repos"

while read -r repo; do
  ${master_mirror_rsync_command} \
    "${master_mirror_rsync_directory}/i686/${repo}/${repo}.db.tar.gz" \
    "${master_mirror_rsync_directory}/i686/${repo}/${repo}.files.tar.gz" \
    "${tmp_dir}/repos/"
  # shellcheck disable=SC2046
  repo-remove "${tmp_dir}/repos/${repo}.db.tar.gz" \
    $(
      grep "^$(str_to_regex "${repo}") " "${tmp_dir}/packages" | \
        cut -d' ' -f2
    )
  ${master_mirror_rsync_command} \
    "${tmp_dir}/repos/${repo}.db.tar.gz" \
    "${tmp_dir}/repos/${repo}.files.tar.gz" \
    "${master_mirror_rsync_directory}/i686/${repo}/"
done < \
  "${tmp_dir}/repositories"

# shellcheck disable=SC2016
{
  printf 'CREATE TEMPORARY TABLE `to_deletes` (`id` BIGINT, UNIQUE KEY (`id`));\n'
  printf 'LOAD DATA LOCAL INFILE "%s" INTO TABLE `to_deletes`;\n' \
    "${tmp_dir}/package-ids"
  printf 'DELETE `binary_packages` FROM `binary_packages` '
  printf ' JOIN `to_deletes` ON `to_deletes`.`id`=`binary_packages`.`id`'
  mysql_join_binary_packages_repositories
  mysql_join_binary_packages_architectures
  printf ';\n'
} | \
  mysql_run_query

tr ' ' '/' < \
  "${tmp_dir}/packages" | \
  sed '
    p
    s/$/.sig/
  ' | \
  sed '
    s,^,rm "i686/,
    s,$,",
  ' | \
  ${master_mirror_sftp_command}