#!/bin/bash
# chkconfig: 2345 95 20
# description: Folding@home Client
# Starts FAHClient
# processname: FAHClient

### BEGIN INIT INFO
# Provides:          FAHClient
# Required-Start:    $remote_fs $syslog $network
# Required-Stop:     $remote_fs $syslog $network
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: Folding@home Client
# Description:       Start and stop Folding@home Client daemon
### END INIT INFO

USER=fahclient
NAME=fahclient
CONFIG=/etc/$NAME/config.xml
DEFAULT=/etc/default/$NAME
HOME=/var/lib/$NAME
EXEC=/usr/bin/FAHClient
LOG=$HOME/log.txt
PID=/var/run/$NAME.pid
EXTRA_OPTS=
QUIET=true
ENABLE=true


if [ -s $DEFAULT ]; then
    . $DEFAULT

    case "x$ENABLE" in
        xtrue|xfalse) ;;
        *)
            echo "Value of ENABLE in $DEFAULT must be either 'true' or 'false';"
            echo "not starting FAHClient."
            ENABLE=false
            ;;
    esac
fi


get_pid() {
    cat $PID
}


is_running() {
    if [ -e $PID ]; then
        ps -hp $(get_pid) 2>/dev/null >/dev/null
        return $?
    else
        return 1
    fi
}


log_status() {
    stat -c "%X" $LOG 2>/dev/null
}


wait_for_log_change() {
    if [ "$2" != "" ]; then
        pid=$2
    else
        pid=$(get_pid)
    fi

    while [ "$(log_status)" == "$1" ]; do        
        if ps -hp $pid 2>/dev/null >/dev/null; then
            sleep 1
        else
            return 1
        fi
    done

    return 0
}


start() {
    if ! $ENABLE; then
        echo "ENABLE set to false in $DEFAULT, not starting FAHClient"
        echo "Use 'force-start' to override."
        return;
    fi

    echo -n "Starting $NAME ... "

    OPTS=
    if [ -e $CONFIG ]; then
        OPTS+="$CONFIG "
    fi
    OPTS+="$EXTRA_OPTS "
    OPTS+="--run-as $USER "
    OPTS+="--pid-file=$PID "
    OPTS+="--daemon "

    if is_running; then
        echo "FAILED"
        echo "$NAME seems to be already running with PID $(get_pid)"
        exit 1
    else
        rm -f $PID
    fi

    if [ ! -d $HOME ]; then
        mkdir -p $HOME
        chown $USER $HOME
    fi
    
    cd $HOME
    LOG_STATUS=$(log_status)

    if $QUIET; then
        $EXEC $OPTS >/dev/null 2>/dev/null &
    else
        $EXEC $OPTS &
    fi

    pid=$!
    if wait_for_log_change "$LOG_STATUS" $pid; then
        echo "OK"
    else
        echo "FAIL"
        exit 1
    fi
}


stop() {
    if [ -e $PID ]; then
        echo -n "Stopping $NAME ... "

        if kill $(get_pid) 2>/dev/null; then
            while is_running; do
                sleep 1
            done
            rm -rf $PID

            echo "OK"
        else
            echo "FAILED"
        fi
    fi
}


reload() {
    echo -n "Reloading $NAME ... "
    LOG_STATUS=$(log_status)
    pid=$(get_pid)
    if is_running && kill -SIGUSR1 $pid 2>/dev/null &&
        wait_for_log_change "$LOG_STATUS" $pid; then
        echo "OK"
    else
        echo "FAIL"
        exit 1
    fi
}


status() {
    if is_running; then
        echo "$NAME is running with PID $(get_pid)"
    else
        echo "$NAME is not running"
    fi
}


log() {
    if [ -e $LOG ]; then
        tail -f $LOG
    fi
}


usage() {
    echo -e "Syntax: $0 [OPTIONS] <COMMAND> [-- [OPTIONS]]"
    echo -e "COMMANDS:"
    echo -e "\tstart          Start client"
    echo -e "\tstop           Stop client"
    echo -e "\trestart        Full stop then restart client"
    echo -e "\treload         Respawn client process"
    echo -e "\tstatus         Print client status"
    echo -e "\tlog            Tail the client log"
    echo -e "OPTIONS:"
    echo -e "\t-u <user>      Run as this user."
    echo -e "\t-h <home>      Run in this directory."
    echo -e "\t-v             Be verbose.  Show WS output"
    echo -e
    echo -e "Any options after a '--' will be passed on to the client."
}

if [ $# -eq 0 ]; then
    usage
    exit 0
fi

EXTRA=false
COMMANDS=
while [ "$1" != "" ]; do
    case "$1" in
        -h) HOME=$2; shift ;;
        -u) USER=$2; shift ;;
        -v) QUIET=false ;;
        --help) usage ;;
        --) EXTRA=true ;;
        -*)
            if $EXTRA; then
                EXTRA_OPTS+="$1 "
            else
                usage
                echo "Invalid argument '$1'"
                exit 1
            fi
            ;;
        *)
            if $EXTRA; then
                EXTRA_OPTS+="$1 "
            else
                COMMANDS+="$1 "
            fi
    esac
    shift
done

for c in $COMMANDS; do
    case $c in
        force-start) ENABLE=true; start ;;
        start) start ;;
        stop) stop ;;
        restart) stop; start ;;
        force-reload|reload) reload ;;
        status) status ;;
        log) log ;;
        *)
            usage
            echo "Invalid command '$1'"
            exit 1
            ;;
    esac
done