#!/bin/bash
#
# plc	Manages all PLC services on this machine
#
# chkconfig: 2345 60 40
#
# description:	Manages all PLC services on this machine
#

# Source function library and configuration
# plc_reload is defined here
. /etc/plc.d/functions

# Verbosity
verbose=0

# All steps should be idempotent. This means that you should be able
# to run them multiple times without depending on anything previously
# being run. The idea is that when the configuration changes, "service
# plc restart" is called, all dependencies are fixed up, and
# everything just works.

### NOTE.
# we want the resulting myplc to be able to easily skip
# some steps. e.g. the packages step takes ages if you install
# all rpms under the repository.
# We skip steps whose name contains a dot (.) or a tilde (~)
# this way the operations would just rename a step name e.g.
# cd /etc/plc.d
# mv packages packages.hide
#
# The drawback is, this stuff does not survive an rpm update
# but that's maybe a good thing, that all is done at first start
###

# do not consider files that contain '.', '~' or 'functions' in the name
steps=($(
for step in /etc/plc.d/* ; do
    stepname=$(basename $step)
    plainstepname=$(echo $stepname | sed -e 's,\.,,' -e 's,~,,' -e 's,functions,,' )
    if [ -f $step -a -x $step -a "$stepname" = "$plainstepname" ] ; then
	priority=$(sed -ne 's/# priority: \(.*\)/\1/p' $step)
	echo $priority $stepname
    fi
done | sort -n | cut -d' ' -f2
))
nsteps=${#steps[@]}

usage()
{
    echo "Usage: $0 [OPTION]... [COMMAND] [STEP]..."
    echo "	-v		Be verbose"
    echo "	-h		This message"
    echo
    echo "Commands:"
    echo "	start		Start all PLC subsystems"
    echo "	stop		Stop all PLC subsystems"
    echo "	reload		Regenerate configuration files"
    echo "	restart		Restart all PLC subsystems"
    echo "	checkpoint filename : Checkpoint the current state of MyPLC to filename"
    echo "	restore filename : Restore MyPLC state from filename"
    echo "	steps		Displays ordered list of subsystems"
    echo
    echo "Steps:"
    for step in "${steps[@]}" ; do
	if [ -x /etc/plc.d/$step ] ; then
	    echo "	$(basename $step)"
	fi
    done
    exit 1
}

# Get options
while getopts "vh" opt ; do
    case $opt in
	v)
	    verbose=1
	    ;;
	h|*)
	    usage
	    ;;
    esac
done

# Redirect stdout and stderr of each step to /var/log/boot.log
if [ $verbose -eq 0 ] ; then
    touch /var/log/boot.log
    chmod 600 /var/log/boot.log
    exec 1>>/var/log/boot.log
    exec 2>>/var/log/boot.log
fi

# Get command
shift $(($OPTIND - 1))
if [ -z "$1" ] ; then
    usage >&3
fi
command=$1

# Get step(s)
shift 1
if [ -z "$1" ] ; then
    # Start or stop everything. Regenerate configuration first.
    plc_reload force
else
    # Start or stop a particular step
    steps=("$@")
    nsteps=${#steps[@]}
fi

RETVAL=0

start ()
{
    for step in "${steps[@]}" ; do
	if [ -x /etc/plc.d/$step ] ; then
	    /etc/plc.d/$step start
	    # Steps may alter the configuration, may need to regenerate
	    plc_reload
	else
	    echo "PLC: $step: unrecognized step" >&4
	    exit 1
	fi
    done
}

stop ()
{
    for i in $(seq 1 $nsteps) ; do
	step=${steps[$(($nsteps - $i))]}
	if [ -x /etc/plc.d/$step ] ; then
	    /etc/plc.d/$step stop
	    # Steps may alter the configuration, may need to regenerate
	    plc_reload
	else
	    echo "PLC: $step: unrecognized step" >&4
	    exit 1
	fi
    done
}

case "$command" in
    start|stop)
	$command
	;;

    restart)
	stop
	start
	;;

    reload)
	plc_reload force
	;;

    checkpoint)
	cpfile=$1
	if [ -z "$cpfile" ] ; then
	    echo "PLC: checkpoint requires a filename as an argument"
	    exit 1
	fi 
	cpdir=$(mktemp -d tmp.XXXXXX)
	cd $cpdir
	mkdir -p ./etc/planetlab/
	rsync -av /etc/planetlab/ ./etc/planetlab/
	/etc/plc.d/db checkpoint ./etc/planetlab/plc_db.checkpoint ./etc/planetlab/plc_drupal.checkpoint
	tar cjf $cpfile etc
	cd -
	rm -rf $cpdir
	;;

    restore)
	cpfile=$1
	cpdir=$(mktemp -d tmp.XXXXXX)
	cd $cpdir
	tar xjf $cpfile
	/etc/plc.d/db restore ./etc/planetlab/plc_db.checkpoint ./etc/planetlab/plc_drupal.checkpoint
	rm -f ./etc/planetlab/plc_db.checkpoint ./etc/planetlab/plc_drupal.checkpoint
	rsync -av ./etc/planetlab/ /etc/planetlab/
	cd -
	rm -rf $cpdir
	;;

    steps)
	echo "${steps[@]}" >&4
	;;

    # for backwards compatibility
    mount|umount|mountstatus)
	echo "${command} not used within native myplc environment"
	;;

    *)
	usage >&3
	;;
esac

exit $RETVAL