#!/usr/bin/env bash

CMD=$1
NOHUP=${NOHUP:=$(which nohup)}
PS=${PS:=$(which ps)}

# default java
JAVA_CMD=${JAVA_CMD:=$(which java)}

get_pid() {
    cat "${GRAYLOG_PID}" 2> /dev/null
}

pid_running() {
    kill -0 $1 2> /dev/null
}

die() {
    echo $*
    exit 1
}

if [ -n "$JAVA_HOME" ]
then
    # try to use $JAVA_HOME
    if [ -x "$JAVA_HOME"/bin/java ]
    then
        JAVA_CMD="$JAVA_HOME"/bin/java
    else
        die "$JAVA_HOME"/bin/java is not executable
    fi
fi

# resolve links - $0 may be a softlink
GRAYLOGCTL="$0"

while [ -h "$GRAYLOGCTL" ]; do
    ls=$(ls -ld "$GRAYLOGCTL")
    link=$(expr "$ls" : '.*-> \(.*\)$')
    if expr "$link" : '/.*' > /dev/null; then
        GRAYLOGCTL="$link"
    else
        GRAYLOGCTL=$(dirname "$GRAYLOGCTL")/"$link"
    fi
done

# take variables from environment if set
GRAYLOGCTL_DIR=${GRAYLOGCTL_DIR:=$(dirname "$GRAYLOGCTL")}
GRAYLOG_SERVER_JAR=${GRAYLOG_SERVER_JAR:=graylog.jar}
GRAYLOG_CONF=${GRAYLOG_CONF:=/etc/graylog/server/server.conf}
GRAYLOG_PID=${GRAYLOG_PID:=/tmp/graylog.pid}
LOG_FILE=${LOG_FILE:=log/graylog-server.log}
LOG4J=${LOG4J:=}
DEFAULT_JAVA_OPTS="-Djava.net.preferIPv4Stack=true -Dlog4j2.formatMsgNoLookups=true -Djdk.tls.acknowledgeCloseNotify=true -Xms1g -Xmx1g -XX:NewRatio=1 -server -XX:+ResizeTLAB -XX:-OmitStackTraceInFastThrow"
if $JAVA_CMD -XX:+PrintFlagsFinal 2>&1 |grep -q UseParNewGC; then
	DEFAULT_JAVA_OPTS="${DEFAULT_JAVA_OPTS} -XX:+UseParNewGC"
fi
if $JAVA_CMD -XX:+PrintFlagsFinal 2>&1 |grep -q UseConcMarkSweepGC; then
	DEFAULT_JAVA_OPTS="${DEFAULT_JAVA_OPTS} -XX:+UseConcMarkSweepGC -XX:+CMSConcurrentMTEnabled -XX:+CMSClassUnloadingEnabled"
fi

JAVA_OPTS="${JAVA_OPTS:="$DEFAULT_JAVA_OPTS"}"

start() {
    echo "Starting graylog-server ..."
    cd "$GRAYLOGCTL_DIR/.."
    "${NOHUP}" "${JAVA_CMD}" ${JAVA_OPTS} ${LOG4J} -jar "${GRAYLOG_SERVER_JAR}" server -f "${GRAYLOG_CONF}" -p "${GRAYLOG_PID}" >> "${LOG_FILE}" 2>> "${LOG_FILE}" &
}

run() {
    echo "Running graylog-server ..."
    cd "$GRAYLOGCTL_DIR/.."
    exec "${JAVA_CMD}" ${JAVA_OPTS} ${LOG4J} -jar "${GRAYLOG_SERVER_JAR}" server -f "${GRAYLOG_CONF}" -p "${GRAYLOG_PID}"
}

stop() {
    if [ ! -f "${GRAYLOG_PID}" ]; then
      die "Not stopping. PID file not found: ${GRAYLOG_PID}"
    fi

    PID=$(get_pid)

    echo "Stopping graylog-server ($PID) ..."
    echo "Waiting for graylog-server to halt."

    kill $PID

    while "$PS" -p $PID > /dev/null; do sleep 1; done;
    rm -f "${GRAYLOG_PID}"

    echo "graylog-server stopped"
}

restart() {
    echo "Restarting graylog-server ..."
    stop
    start
}

status() {
    PID=$(get_pid)
    if [ ! -z $PID ]; then
        if pid_running $PID; then
            echo "graylog-server running with PID ${PID}"
            return 0
        else
            rm "${GRAYLOG_PID}"
            die "Removed stale PID file ${GRAYLOG_PID} with ${PID}."
        fi
    fi

    die "graylog-server not running"
}

case "$CMD" in
    start)
        start
        ;;
    stop)
        stop
        ;;
    restart)
        restart
        ;;
    status)
        status
        ;;
    run)
        run
        ;;
    *)
        echo "Usage $0 {start|stop|restart|status|run}"
esac