#!/bin/sh
#
# upgrade-sakai

set -e

#--- auxiliary functions ---#
#

Warn() { echo $0: $@ 1>&2; }

Die() { Warn fatal error: $@; exit 1; }

Usage()
{
  cat 1>&2 <<ZZ
Usage: $0

to restart Tomcat and upgrade Sakai.

Environment variables:

  NO_UPGRADE=1

    Don't upgrade Sakai, just restart.

  NO_TAIL=1

    Don't tail catalina.out after restarting.

  CATALINA_BASE

     The directory with the Tomcat instance to use.

  SAKAI_BUILD

     The directory with the Sakai build to use.

ZZ
  exit 0
}

#With_x() { set -x; "$@"; set +x; }
# echoes the set +x
With_x() ( set -x; "$@" )

MyTomcatIsRunning()
# not foolproof: you might be running a *different* Tomcat
{
  lsof -i tcp |
  awk '/TCP \*:.*(LISTEN)/ {print $2}' |
  sort -u |
  while read p
  do
    ps -p $p -o cmd
  done |
  fgrep -qe -Dcatalina.base=
}

HomeOf()
{
  if [ -n "$1" ]
  then
    getent passwd "$1" | awk -F: '{print $6}'
  fi
}

#--- start ---#
#

case "$1" in
-h|-?|--help) Usage;;
esac

# turn $NO_UPGRADE into something that is always 0 or 1

do_upgrade=1

case "$NO_UPGRADE" in
1|y|yes) do_upgrade=0;;
esac

# turn $NO_TAIL into something that is always 0 or 1

do_tail=1

case "$NO_TAIL" in
1|y|yes) do_tail=0;;
esac

# set the path to the Sakai build

if [ -z "$SAKAI_BUILD" ]
then
  sudo_home=`HomeOf "$SUDO_USER"`

  if [ -n "$HOME" -a -d $HOME/sakai-deployed-`date +%F` ]
  then
    SAKAI_BUILD=$HOME/sakai-deployed-`date +%F`
  elif [ -n "$SUDO_USER" -a -d "$sudo_home"/sakai-deployed-`date +%F` ]
  then
    SAKAI_BUILD="$sudo_home"/sakai-deployed-`date +%F`
  else
    SAKAI_BUILD=/home/sakai11x/sakai-deployed-`date +%F`
  fi
fi

ContainsNoSakaiBuild()
{
  # let's keep it simple
  [ ! -d "$1"/components ]
}

if [ $do_upgrade = 1 ]
then
  # we do want to upgrade

  if [ ! -d "$SAKAI_BUILD" ]
  then
    echo Die cannot find build directory: $SAKAI_BUILD
  fi

  if ContainsNoSakaiBuild "$SAKAI_BUILD"
  then
    Die build directory seems wrong: $SAKAI_BUILD
  fi
fi

if [ -z "$CATALINA_BASE" ]
then
  CATALINA_BASE=$HOME/tomcat8
fi

[ -d $CATALINA_BASE ] ||
  Die cannot see the Tomcat installation in: $CATALINA_BASE

if [ ! -x $CATALINA_BASE/bin/shutdown.sh ]
then
  Die Tomcat installation directory seems wrong: $CATALINA_BASE
fi

owner=`stat -c%u $CATALINA_BASE`

if [ X`id -u` != X"$owner" ]
then
  # retry as the owner of $CATALINA_BASE
  sudo -u "$owner" /usr/bin/env \
    CATALINA_BASE=$PWD \
    SAKAI_BUILD="$SAKAI_BUILD" \
    NO_UPGRADE="$NO_UPGRADE" \
    NO_TAIL="$NO_TAIL" \
    "$0" "$@"
fi

if MyTomcatIsRunning
then
  With_x $CATALINA_BASE/bin/shutdown.sh
fi

if [ $do_upgrade = 1 ]
then
  for d in components lib webapps
  do
    With_x rm -rf $CATALINA_BASE/$d
  done
  With_x rsync -a $SAKAI_BUILD/. $CATALINA_BASE/.
fi

while MyTomcatIsRunning
do
  sleep 1
done

With_x $CATALINA_BASE/bin/startup.sh

if [ $do_tail = 1 ]
then
  # we do want to tail
   tail -f $CATALINA_BASE/logs/catalina.out
fi