#!/bin/bash

source /etc/conf.d/spigot || echo "Could not source /etc/conf.d/spigot"

# You may use this script for any minecraft server of your choice, just alter the config file
SERVER_ROOT="${SERVER_ROOT:-/srv/craftbukkit}"
BACKUPPATH="${BACKUPPATH:-/srv/craftbukkit/backup}"
LOGPATH="${LOGPATH:-/srv/craftbukkit/logs}"
WORLDPATHS="${WORLDPATHS:-/srv/craftbukkit/world /srv/craftbukkit/world_nether /srv/craftbukkit/world_the_end}"
KEEP_BACKUPS="${KEEP_BACKUPS:-10}"
MC_USER="${MC_USER:-craftbukkit}"
MAIN_JAR="${MAIN_JAR:-spigot.jar}"
SESSION_NAME="${SESSION_NAME:-spigot}"

# Specify system parameters for the minecraft server
MINHEAP="${MINHEAP:-512M}"
MAXHEAP="${MAXHEAP:-1024M}"
THREADS="${THREADS:-1}"
JAVA_PARMS="${JAVA_PARMS:-"-Xmx${MAXHEAP} -Xms${MINHEAP} -XX:ParallelGCThreads=${THREADS}"}"

# Check for sudo rigths
if [ $(sudo whoami) != "root" ]; then
    echo "You must have sudo access in order to use this script."
    exit 1
fi

# Pipe any given argument to the minecraft server console
mc_command() {
	sudo -u ${MC_USER} screen -S ${SESSION_NAME} -X stuff "`printf \"$*\r\"`"
}

# Start the server if it is not already running
server_start() {
    sudo -u ${MC_USER} screen -S ${SESSION_NAME} -Q select . > /dev/null
    if [ $? -eq 0 ]; then
        echo "A screen ${SESSION_NAME} session is already running. Please close it first."
    else
        echo -en "Starting server... "
        sudo -u ${MC_USER} screen -dmS ${SESSION_NAME} /bin/bash -c "cd ${SERVER_ROOT}; java ${JAVA_PARMS} -jar ${SERVER_ROOT}/${MAIN_JAR} nogui"
        echo -e "\e[39;1m done\e[0m"
    fi
}

# Stop the server gracefully by saving everything prior and warning the users
server_stop() {
    sudo -u ${MC_USER} screen -S ${SESSION_NAME} -Q select . > /dev/null
    if [ $? -eq 0 ]; then
        mc_command save-all
        mc_command say "Server is going down in 10 seconds! HURRY UP WITH WATHEVER YOU ARE DOING!" # Warning the users
        echo -en "Server is going down in... "
        for i in $(seq 1 10);
        do
            mc_command say "down in... $(expr 10 - $i)"
            echo -n " $(expr 10 - $i)"
            sleep 1
        done
        mc_command stop
        echo -e "\e[39;1m done\e[0m"
    else
        echo "The corresponding screen session for ${SESSION_NAME} was already dead."
    fi
}

# Print whether the server is running and if so give some information about memory usage and threads
server_status() {
    sudo -u ${MC_USER} screen -S ${SESSION_NAME} -Q select . > /dev/null
    if [ $? -eq 0 ]; then
        echo -e "Status:\e[39;1m running\e[0m"

        # Calculating memory usage
        for p in $(sudo -u ${MC_USER} pgrep -f ${MAIN_JAR}); do
            ps -p$p -O rss | tail -n1;
        done | gawk '{ count ++; sum += $2 }; END {count --; print "Number of processes =", count, "(screen, bash,", count-2, "x java)"; print "Total memory usage =", sum/1024, "MB" ;};'
    else
        echo -e "Status:\e[39;1m stopped\e[0m"
    fi
}

# Restart the complete server by shutting it down and starting it again
server_restart() {
    sudo -u ${MC_USER} screen -S ${SESSION_NAME} -Q select . > /dev/null
    if [ $? -eq 0 ]; then
        server_stop
        sleep 0.1
        server_start
    else
        server_start
    fi
}

# Backup the directories specified in $WORLDPATHS
backup_files() {
    which tar &> /dev/null
    if [ $? -ne 0 ]; then
        echo "The tar binaries are needed for a backup."
        exit 2
    fi

    echo "Starting backup..."
    FILE="`date +%Y%m%d%H%M%S`.tar.gz"
    sudo -u ${MC_USER} mkdir -p ${BACKUPPATH}
    sudo -u ${MC_USER} screen -S ${SESSION_NAME} -Q select . > /dev/null
    if [ $? -eq 0 ]; then
        mc_command save-off
        mc_command save-all
        sync && wait
        sudo -u ${MC_USER} tar -czf ${BACKUPPATH}/${FILE} --totals ${WORLDPATHS} 2>&1 | grep -v "tar: Removing leading "
        mc_command save-on
    else
        sudo -u ${MC_USER} tar -czf ${BACKUPPATH}/${FILE} --totals ${WORLDPATHS} 2>&1 | grep -v "tar: Removing leading "
    fi
    echo -e "\e[39;1mbackup completed\e[0m\n"

    echo -n "Only keeping the last ${KEEP_BACKUPS} backups and removing the other ones..."
    BACKUP_COUNT=$(for f in ${BACKUPPATH}/[0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9]*; do echo $f; done | wc -l)
    if [ $(expr ${BACKUP_COUNT} - ${KEEP_BACKUPS}) -gt 0 ]; then
        sudo -u ${MC_USER} rm $(for f in ${BACKUPPATH}/[0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9]*; do echo $f; done | head -n$(expr ${BACKUP_COUNT} - ${KEEP_BACKUPS}))
        echo -e "\e[39;1m done\e[0m ($(expr ${BACKUP_COUNT} - ${KEEP_BACKUPS}) backup(s) pruned)"
    else
        echo -e "\e[39;1m done\e[0m (no backups pruned)"
    fi
}

# Run the given comman at the minecraft server console
server_command() {
    if [ $# -lt 1 ]; then
        echo "No server command specified. Try 'help' for a list of commands."
        exit 1
    fi

    sudo -u ${MC_USER} screen -S ${SESSION_NAME} -Q select . > /dev/null
    if [ $? -eq 0 ]; then
    	mc_command "$@"
        tailf -n 0 ${LOGPATH}/latest.log &
        TAILFPID=$! # Process id of tailf command
        sleep 0.1
        kill ${TAILFPID}
    else
        echo "There is no ${SESSION_NAME} session to connect to."
    fi
}

# Enter the screen minecraft session
server_console() {
    sudo -u ${MC_USER} screen -S ${SESSION_NAME} -Q select . > /dev/null
    if [ $? -eq 0 ]; then
        sudo -u ${MC_USER} screen -S ${SESSION_NAME} -rx
    else
        echo "There is no ${SESSION_NAME} session to connect to."
    fi
}

# Help function, no arguments required
help() {
    cat << 'EOF'
This script was design to easily control any minecraft server. Quite every parameter for a given
minecraft server derivative can be altered by editing the variables in the configuration file.

Usage: spigot {start|stop|status|backup|command <command>|console}
    start                Start the minecraft server
    stop                 Stop the minecraft server
    restart              Restart the minecraft server
    status               Print some status information
    backup               Backup the world data
    command <command>    Run the given comman at the minecraft server console
    console              Enter the server console through a screen session

Copyright (c) Gordian Edenhofer <gordian.edenhofer@gmail.com>
EOF
}

case "$1" in
	start)
		server_start
		;;

	stop)
        server_stop
		;;

    status)
        server_status
        ;;

    restart)
        server_restart
        ;;

	console)
		server_console
		;;

    command)
        server_command "${@:2}"
        ;;

	backup)
        backup_files
		;;

	*|-h|--help)
		help
esac

exit 0