#!/bin/bash

# Copyright (c) 2015, 2016, Oracle and/or its affiliates. All rights reserved.
#
# 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; version 2 of the License.
#
# 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA

set -e

# It is possible that Debconf has already been removed, too.
if [ -f /usr/share/debconf/confmodule ]; then
  . /usr/share/debconf/confmodule
fi

if [ -n "$DEBIAN_SCRIPT_DEBUG" ]; then set -v -x; DEBIAN_SCRIPT_TRACE=1; fi
${DEBIAN_SCRIPT_TRACE:+ echo "#42#DEBUG# RUNNING $0 $*" 1>&2 }

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

# To avoid having hardcoded paths in the script, we do a search on the path, as suggested at:
# https://www.debian.org/doc/manuals/developers-reference/ch06.en.html#bpp-debian-maint-scripts
pathfind() {
  OLDIFS="$IFS"
  IFS=:
  for p in $PATH; do
    if [ -x "$p/$*" ]; then
      IFS="$OLDIFS"
      return 0
    fi
  done
  IFS="$OLDIFS"
  return 1
}

# Choose the proper mechanism. Ubuntu 16.04 uses systemd but still provides invoke-rc.d,
# so the existence of systemd must be checked first.
invoke() {
	if pathfind systemctl; then
		systemctl $1 "@DEB_SYSTEMD_SERVICE_NAME@"
	elif pathfind invoke-rc.d; then
		invoke-rc.d mysql $1
	else
		/etc/init.d/mysql $1
	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!
stop_server() {
  set +e
  invoke stop
  errno=$?
  set -e

  if [ "$?" != 0 ]; then
    echo "Trying to stop the MySQL server resulted in exitcode $?." 1>&2
    echo "Stop it yourself and try again!" 1>&2
    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

# New packaging paradigm for my.cnf as of Dec-2014 for sharing mysql
# variants in Ubuntu.
case "$1" in
  remove|disappear)
    [ -x /usr/share/mysql-common/configure-symlinks ] && /usr/share/mysql-common/configure-symlinks remove mysql "$mysql_cfgdir/mysql.cnf"
  ;;
esac

#
# - Do NOT purge logs or data if another mysql-sever* package is installed (#307473)
# - Remove the mysql user only after all his owned files are purged.
#   
if [ "$1" = "purge" -a ! \( -x /usr/sbin/mysqld -o -L /usr/sbin/mysqld \) ]; 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 mysql-@DEB_PRODUCTNAME@-server/postrm_remove_databases || true
  db_go || true
  db_get mysql-@DEB_PRODUCTNAME@-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
    rm -rf /var/lib/mysql
    rm -rf /var/lib/mysql-files
    rm -rf /var/lib/mysql-keyring
    userdel mysql || true
  fi
fi

#DEBHELPER#

exit 0