#!/bin/bash

# /etc/init.d/minecraft

# version 0.3.6 2011-10-17 (YYYY-MM-DD)

### BEGIN INIT INFO

# Provides:   minecraft

# Required-Start: $local_fs $remote_fs

# Required-Stop:  $local_fs $remote_fs

# Should-Start:   $network

# Should-Stop:    $network

# Default-Start:  2 3 4 5

# Default-Stop:   0 1 6

# Short-Description:    Minecraft server

# Description:    Starts the minecraft server

### END INIT INFO

#Settings

SERVICE='minecraft_server.jar'

OPTIONS='nogui'

USERNAME='minecraft'

WORLD='world'

MCPATH='/usr/local/minecraft'

BACKUPPATH='/usr/local/minecraft/backup'

CPU_COUNT=1

INVOCATION="java -Xmx1024M -Xms1024M -Djava.net.preferIPv4Stack=true -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalPacing -XX:ParallelGCThreads=$CPU_COUNT -XX:+AggressiveOpts -jar $SERVICE $OPTIONS"

ME=`whoami`

as_user() {

  if [ $ME == $USERNAME ] ; then

    bash -c "$1"

  else

    su - $USERNAME -c "$1"

  fi

}

mc_start() {

  if  pgrep -u $USERNAME -f $SERVICE > /dev/null

  then

    echo "$SERVICE is already running!"

  else

    echo "Starting $SERVICE..."

    cd $MCPATH

    as_user "cd $MCPATH && screen -dmS minecraft $INVOCATION"

    sleep 7

    if pgrep -u $USERNAME -f $SERVICE > /dev/null

    then

      echo "$SERVICE is now running."

    else

      echo "Error! Could not start $SERVICE!"

    fi

  fi

}

mc_saveoff() {

  if pgrep -u $USERNAME -f $SERVICE > /dev/null

  then

    echo "$SERVICE is running... suspending saves"

    as_user "screen -p 0 -S minecraft -X eval 'stuff "say SERVER BACKUP STARTING. Server going readonly..."15'"

    as_user "screen -p 0 -S minecraft -X eval 'stuff "save-off"15'"

    as_user "screen -p 0 -S minecraft -X eval 'stuff "save-all"15'"

    sync

    sleep 10

  else

    echo "$SERVICE is not running. Not suspending saves."

  fi

}

mc_saveon() {

  if pgrep -u $USERNAME -f $SERVICE > /dev/null

  then

    echo "$SERVICE is running... re-enabling saves"

    as_user "screen -p 0 -S minecraft -X eval 'stuff "save-on"15'"

    as_user "screen -p 0 -S minecraft -X eval 'stuff "say SERVER BACKUP ENDED. Server going read-write..."15'"

  else

    echo "$SERVICE is not running. Not resuming saves."

  fi

}

mc_stop() {

  if pgrep -u $USERNAME -f $SERVICE > /dev/null

  then

    echo "Stopping $SERVICE"

    as_user "screen -p 0 -S minecraft -X eval 'stuff "say SERVER SHUTTING DOWN IN 10 SECONDS. Saving map..."15'"

    as_user "screen -p 0 -S minecraft -X eval 'stuff "save-all"15'"

    sleep 10

    as_user "screen -p 0 -S minecraft -X eval 'stuff "stop"15'"

    sleep 7

  else

    echo "$SERVICE was not running."

  fi

  if pgrep -u $USERNAME -f $SERVICE > /dev/null

  then

    echo "Error! $SERVICE could not be stopped."

  else

    echo "$SERVICE is stopped."

  fi

}

mc_update() {

  if pgrep -u $USERNAME -f $SERVICE > /dev/null

  then

    echo "$SERVICE is running! Will not start update."

  else

    MC_SERVER_URL=http://s3.amazonaws.com/MinecraftDownload/launcher/minecraft_server.jar?v=`date | sed "s/[^a-zA-Z0-9]/_/g"`

    as_user "cd $MCPATH && wget -q -O $MCPATH/minecraft_server.jar.update $MC_SERVER_URL"

    if [ -f $MCPATH/minecraft_server.jar.update ]

    then

      if `diff $MCPATH/$SERVICE $MCPATH/minecraft_server.jar.update >/dev/null`

      then

        echo "You are already running the latest version of $SERVICE."

      else

        as_user "mv $MCPATH/minecraft_server.jar.update $MCPATH/$SERVICE"

        echo "Minecraft successfully updated."

      fi

    else

      echo "Minecraft update could not be downloaded."

    fi

  fi

}

mc_backup() {

   echo "Backing up minecraft world..."

   if [ -d $BACKUPPATH/${WORLD}_`date "+%Y.%m.%d_%H.%M"` ]

   then

     for i in 1 2 3 4 5 6

     do

       if [ -d $BACKUPPATH/${WORLD}_`date "+%Y.%m.%d_%H.%M"`-$i ]

       then

         continue

       else

         as_user "cd $MCPATH && cp -r $WORLD $BACKUPPATH/${WORLD}_`date "+%Y.%m.%d_%H.%M"`-$i"

         break

       fi

     done

   else

     as_user "cd $MCPATH && cp -r $WORLD $BACKUPPATH/${WORLD}_`date "+%Y.%m.%d_%H.%M"`"

     echo "Backed up world"

   fi

   echo "Backing up $SERVICE"

   if [ -f "$BACKUPPATH/minecraft_server_`date "+%Y.%m.%d_%H.%M"`.jar" ]

   then

     for i in 1 2 3 4 5 6

     do

       if [ -f "$BACKUPPATH/minecraft_server_`date "+%Y.%m.%d_%H.%M"`-$i.jar" ]

       then

         continue

       else

         as_user "cd $MCPATH && cp $SERVICE "$BACKUPPATH/minecraft_server_`date "+%Y.%m.%d_%H.%M"`-$i.jar""

         break

       fi

     done

   else

     as_user "cd $MCPATH && cp $SERVICE "$BACKUPPATH/minecraft_server_`date "+%Y.%m.%d_%H.%M"`.jar""

   fi

   echo "Backup complete"

}

mc_command() {

  command="$1";

  if pgrep -u $USERNAME -f $SERVICE > /dev/null

  then

    pre_log_len=`wc -l "$MCPATH/server.log" | awk '{print $1}'`

    echo "$SERVICE is running... executing command"

    as_user "screen -p 0 -S minecraft -X eval 'stuff "$command"15'"

    sleep .1 # assumes that the command will run and print to the log file in less than .1 seconds

    # print output

    tail -n $[`wc -l "$MCPATH/server.log" | awk '{print $1}'`-$pre_log_len] "$MCPATH/server.log"

  fi

}

#Start-Stop here

case "$1" in

  start)

    mc_start

    ;;

  stop)

    mc_stop

    ;;

  restart)

    mc_stop

    mc_start

    ;;

  update)

    mc_stop

    mc_backup

    mc_update

    mc_start

    ;;

  backup)

    mc_saveoff

    mc_backup

    mc_saveon

    ;;

  status)

    if pgrep -u $USERNAME -f $SERVICE > /dev/null

    then

      echo "$SERVICE is running."

    else

      echo "$SERVICE is not running."

    fi

    ;;

  command)

    if [ $# -gt 1 ]; then

      shift

      mc_command "$*"

    else

      echo "Must specify server command (try 'help'?)"

    fi

    ;;

  *)

  echo "Usage: $0 {start|stop|update|backup|status|restart|command "server command"}"

  exit 1

  ;;

esac

exit 0