#!/bin/bash
set -e

# shellcheck source=/dev/null
. /usr/share/debconf/confmodule

if [ -n "$DEBIAN_SCRIPT_DEBUG" ]
then
  set -v -x
  DEBIAN_SCRIPT_TRACE=1
fi

${DEBIAN_SCRIPT_TRACE:+ echo "#42#DEBUG# RUNNING $0 $*" 1>&2 }

MYADMIN="/usr/bin/mysqladmin --defaults-file=/etc/mysql/debian.cnf"

MARIADBD_USERS="root"

# Check if user 'mysql' exists before referring to it in pgrep
# to avoid pgrep erroring on 'invalid user name'
if id mysql > /dev/null 2>&1
then
  MARIADBD_USERS="$MARIADBD_USERS,mysql"
fi

# Try to stop the server in a sane way. If it does not success let the admin
# do it himself. No database directories should be removed while the server
# is running! Another mariadbd in e.g. a different chroot is fine for us.
stop_server() {
  # Return immediately if there are no mysqld processes running
  # as there is no point in trying to shutdown in that case.
  if ! pgrep -x -u "$MARIADBD_USERS" --nslist pid --ns $$ "mysqld|mariadbd" > /dev/null
  then
    return
  fi

  set +e
  invoke-rc.d mariadb stop
  invoke-rc.d mysql stop # Backwards compatibility
  errno=$?
  set -e

  # systemctl could emit exit code 100=no init script (fresh install)
  if [ "$errno" != 0 ] && [ "$errno" != 100 ]
  then
    echo "Attempt to stop MariaDB/MySQL server returned exitcode $errno" 1>&2
    echo "There is a MariaDB/MySQL server running, but we failed in our attempts to stop it." 1>&2
    echo "Check if there is any server running with 'pgrep \"mysqld|mariadbd\"' and" 1>&2
    echo "try to stop it yourself by issuing 'invoke-rc.d mariadb stop'." 1>&2
    db_stop
    exit 1
  fi
}


case "$1" in
  purge|remove|upgrade|failed-upgrade|abort-install|abort-upgrade|disappear)
    if [ -n "$($MYADMIN ping 2>/dev/null)" ]
    then
      stop_server
      sleep 2
    fi
    ;;
  *)
    echo "postrm called with unknown argument '$1'" 1>&2
    exit 1
    ;;
esac

#
# - Purge logs and data only if they are ours (#307473)
# - Remove the mysql user only after all his owned files are purged.
# - Cleanup the initscripts only if this was the last provider of them
#
if [ "$1" = "purge" ] && [ -f "/var/lib/mysql/debian-__MARIADB_MAJOR_VER__.flag" ]
then
  # we remove the mysql user only after all his owned files are purged
  rm -f /var/log/mysql.{log,err}{,.0,.[1234567].gz}
  rm -rf /var/log/mysql

  db_input high "mariadb-server/postrm_remove_databases" || true
  db_go || true
  db_get "mariadb-server/postrm_remove_databases" || true
  if [ "$RET" = "true" ]
  then
    # never remove the debian.cnf when the databases are still existing
    # else we ran into big trouble on the next install!
    rm -f /etc/mysql/debian.cnf
    # Remove all contents from /var/lib/mysql except if it's a
    # directory with file system data. See #829491 for details and
    # #608938 for potential mysql-server leftovers which erroneously
    # had been renamed.
    # Attempt removal only if the directory hasn't already been removed
    # by dpkg to avoid failing on "No such file or directory" errors.
    if [ -d /var/lib/mysql ]
    then
      find /var/lib/mysql -mindepth 1 \
        -not -path '*/lost+found/*'     -not -name 'lost+found' \
        -not -path '*/lost@002bfound/*' -not -name 'lost@002bfound' \
        -delete

      # "|| true" still needed as rmdir still exits with non-zero if
      # /var/lib/mysql is a mount point
      rmdir --ignore-fail-on-non-empty /var/lib/mysql || true
    fi
    rm -rf /run/mysqld # this directory is created by the init script, don't leave behind
    userdel mysql || true
  fi

fi

#DEBHELPER#

# Modified dh_systemd_start snippet that's not added automatically
if [ -d /run/systemd/system ]
then
  systemctl --system daemon-reload >/dev/null || true
fi