#!/bin/sh
##  The contents of this file are subject to the Mozilla Public License
##  Version 1.1 (the "License"); you may not use this file except in
##  compliance with the License. You may obtain a copy of the License
##  at http://www.mozilla.org/MPL/
##
##  Software distributed under the License is distributed on an "AS IS"
##  basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
##  the License for the specific language governing rights and
##  limitations under the License.
##
##  The Original Code is RabbitMQ.
##
##  The Initial Developer of the Original Code is GoPivotal, Inc.
##  Copyright (c) 2007-2015 Pivotal Software, Inc.  All rights reserved.
##

SCRIPT="$(basename "$0")"
RABBITMQ_ENV=/usr/lib/rabbitmq/bin/rabbitmq-env
RABBITMQ_SCRIPTS_DIR="$(dirname "$RABBITMQ_ENV")"

main() {
  ensure_we_are_in_a_readable_dir
  if current_user_is_rabbitmq && calling_rabbitmq_server
  then
    exec_rabbitmq_server "$@"
  elif current_user_is_rabbitmq && ! calling_rabbitmq_plugins
  then
    exec_script_as_rabbitmq "$@"
  elif current_user_is_root && calling_rabbitmq_plugins
  then
    exec_script_as_rabbitmq "$@"
  elif current_user_is_root
  then
    exec_script_as_root "$@"
  else
    run_script_help_and_fail
  fi
}

ensure_we_are_in_a_readable_dir() {
  # shellcheck disable=SC2164
  cd ~rabbitmq || cd /
}

current_user_is_rabbitmq() {
  [ "$(id -un)" = "rabbitmq" ]
}

current_user_is_root() {
  [ "$(id -u)" = 0 ]
}

calling_rabbitmq_server() {
  [ "$SCRIPT" = "rabbitmq-server" ]
}

calling_rabbitmq_plugins() {
  [ "$SCRIPT" = "rabbitmq-plugins" ]
}

exec_rabbitmq_server() {
  RABBITMQ_ENV=/usr/lib/rabbitmq/bin/rabbitmq-env
  # RABBITMQ_SCRIPTS_DIR is used in rabbitmq-env
  # shellcheck disable=SC2034
  RABBITMQ_SCRIPTS_DIR="$(dirname "$RABBITMQ_ENV")"
  # shellcheck source=/dev/null
  . "$RABBITMQ_ENV"

  exec /usr/lib/rabbitmq/bin/rabbitmq-server "$@" @STDOUT_STDERR_REDIRECTION@
}

exec_script_as_rabbitmq() {
  HOME="$(cd ~rabbitmq && pwd)" exec "/usr/lib/rabbitmq/bin/$SCRIPT" "$@"
}

exec_script_as_root() {
  if [ -x /sbin/runuser ]
  then
    # TODO:
    # At some point all of the RabbitMQ supported distributions will be using
    # the util-linux version of /sbin/runuser, as it has been removed from GNU
    # coreutils as of 2012. At that point the first clause of the following
    # if statement can become the only statement used and the if/then
    # removed
    if /sbin/runuser --version | grep -qF util-linux
    then
        exec /sbin/runuser -u rabbitmq -- "/usr/lib/rabbitmq/bin/$SCRIPT" "$@"
    else
        exec /sbin/runuser -s /bin/sh -- rabbitmq "/usr/lib/rabbitmq/bin/$SCRIPT" "$@"
    fi
  elif [ -x /bin/su ]
  then
    exec /bin/su -s /bin/sh rabbitmq -- "/usr/lib/rabbitmq/bin/$SCRIPT" "$@"
  else
    echo "Please ensure /bin/su or /sbin/runuser exists and can be executed by $USER." 1>&2
    exit 1
  fi
}

run_script_help_and_fail() {
  "/usr/lib/rabbitmq/bin/$SCRIPT" help

  echo "
Only root or rabbitmq can run $SCRIPT
"
  exit 1
}

main "$@"