#!/bin/sh
#
# Start a headless game server (and keep it running)
#
# Using this script, a headless game server is started, waiting for players to
# connect (if your firewall configuration permits). Players connect and start a
# game. As soon as the game ends, the server will quit, and this script will
# start up a new server immidiately. This is a stability measure to  rule out
# the unlikely case where side effects (such as memory leaks or corruption)
# could drain on system resources.
#
# For this to work, Internet originated traffic must be able to reach the
# server on the following ports:
# TCP port 61357: game protocol port
# TCP port 61358: FTP control port
# TCP ports 61359 to 61366: FTP data ports
#
# Once publishing to the master server succeeded (this can be verified at
# master server's site) you may connect to your headless game server
# using a copy of game you have installed on a Desktop computer. The first
# user connecting to a headless server controls it. If this user disconnects,
# the next user who connects (or had already connected) takes control.
#
# Please read http://wiki.megaglest.org/Dedicated_Server for more information
#
# ----------------------------------------------------------------------------
# 2013 Written by Tom Reynolds <tomreyn[at]megaglest.org>
# 2015 Rewritten by filux <heross(@@)o2.pl>
# Copyright (c) 2013-2015 under GNU GPL v3.0+
# ----------------------------------------------------------------------------
LANG=C
trap "kill -- -$$" HUP INT QUIT TERM EXIT

KERNEL="$(uname -s | tr '[A-Z]' '[a-z]')"
if [ "$KERNEL" = "linux" ] || [ "$(echo "$(readlink -f "$0" >/dev/null 2>&1; echo $?)" | grep '^[0-9]$')" -eq "0" ]; then
    GAMEDIR="$(dirname "$(readlink -f "$0")")"
else
    GAMEDIR="$(cd "$(dirname "$0")"; pwd)"
fi
HOME_DIR="$HOME"
B_SCRIPT_DIR="$GAME_DIR"

# -------
# useful for mods
BASIC_SCRIPT="start_megaglest"
FAKE_EXC_BINARY_MAC="MegaGlest"
EXC_BINARY="megaglest"
SHORT_GAME_NAME="megaglest"
# -------
PORTSTART=62001
NUM_OA_SERVERS=2
# Log file location (beware, this can grow large)
# LOG_SERVER=/dev/null

if [ "$(which curl 2>/dev/null)" = "" ]; then
    echo "WARNING: Downloading tool 'curl' DOES NOT EXIST on this system, please install it." >&2
fi
if [ "$KERNEL" = "darwin" ]; then
	if [ -e "$GAMEDIR/../../MacOS/$FAKE_EXC_BINARY_MAC" ]; then
		BASIC_SCRIPT="$FAKE_EXC_BINARY_MAC"; B_SCRIPT_DIR="$(cd "${GAMEDIR}/../../MacOS/"; pwd)"
	elif [ -e "$GAMEDIR/$FAKE_EXC_BINARY_MAC.sh" ]; then
		BASIC_SCRIPT="$FAKE_EXC_BINARY_MAC.sh"
	fi
fi
if [ "$(which lscpu 2>/dev/null)" != "" ]; then NUMCORES="$(lscpu -p | grep -cv '^#')"
    elif [  "$(which sysctl 2>/dev/null)" != "" ]; then NUMCORES="$(sysctl -n hw.ncpu)"; fi
if [ "$NUMCORES" = "" ]; then NUMCORES=1; fi
echo "Notice: Detected processor with $NUMCORES cores." >&2
case $NUMCORES in
    1) MAX_LOAD_MULT="0.65";; 2) MAX_LOAD_MULT="0.80";; 3) MAX_LOAD_MULT="0.90";; *) MAX_LOAD_MULT="0.95";;
esac
MAX_LOAD="$(echo "$NUMCORES $MAX_LOAD_MULT" | awk '{print $1*$2}')"

if [ "$1" != "" ] && [ "$(echo "$1" | grep '^[0-9]\+$')" != "" ]; then SERVERCOUNT="$1"
    else SERVERCOUNT=0; fi
if [ "$2" != "" ] && [ "$(echo "$2" | grep '[0-9.:]\+' | grep -v '[A-Za-z]')" != "" ]; then
    SERVER_GREP_IP="$(echo "$2" | sed 's/\./\\./g')"; else SERVER_GREP_IP=""; fi
if [ "$3" != "" ] && [ "$(echo "$3" | grep '^[0-9]\+$')" != "" ]; then PORTSTART="$3"; fi
PORT="$(($PORTSTART + $(($(($SERVERCOUNT - 1)) * 11))))"
STATUSPORT="$(($PORT - 1))"
PORT_FD="$(echo "$PORT" | cut -c1-3)"

SERVER_SCRIPT="$(basename "$0")"
if [ -f "$GAMEDIR/glest.ini" ]; then
    GLEST_INI="$(cat "$GAMEDIR/glest.ini")"
    LOG_DIR="$(echo "$GLEST_INI" | awk -F '=' '/^LogPath=/ {print $2}' | sed -e 's:\$HOME:'"$HOME_DIR"':g')"
    MASTER_SERVER="$(echo "$GLEST_INI" | awk -F '=' '/^Masterserver=/ {print $2}')"
    if [ "$(echo "$MASTER_SERVER" | grep '/$')" ]; then CLEAR_M_SERVER="${MASTER_SERVER}showServersForGlest.php"
	else CLEAR_M_SERVER="$MASTER_SERVER/showServersForGlest.php"; fi
elif [ "$SERVER_GREP_IP" != "" ]; then
    echo "WARNING: file 'glest.ini' not found, maybe '$SERVER_SCRIPT' script is placed in the wrong location." >&2
fi

if [ -e "$B_SCRIPT_DIR/$BASIC_SCRIPT" ]; then SERVER_EXEC="$B_SCRIPT_DIR/$BASIC_SCRIPT"
    elif [ -e "$GAMEDIR/$EXC_BINARY" ]; then SERVER_EXEC="$GAMEDIR/$EXC_BINARY"
    else SERVER_EXEC="$EXC_BINARY"; fi
if [ "$SERVERCOUNT" -eq "0" ]; then
    if [ "$SERVER_EXEC" != "$EXC_BINARY" ]; then ulimit -c unlimited; fi
    USED_PORTS=""; LOG_FILE="server.log"
else
    USED_PORTS=" --use-ports=$PORT,$PORT,$STATUSPORT"
    LOG_FILE="server_${SERVERCOUNT}.log"
    echo "Info: Server nr. $SERVERCOUNT ($2 ; $PORT)." >&2
fi
SER_PARAMETERS="--headless-server-mode=vps,exit$USED_PORTS"
SER_GREP_PARAMETERS="$(echo "$SER_PARAMETERS" | sed 's/--/\\--/g')"
if [ "$SERVERCOUNT" -gt "0" ]; then
    sleep "$(($SERVERCOUNT * 30))"s
fi

if [ "$LOG_SERVER" != "" ]; then :
elif [ "$LOG_DIR" != "" ]; then
    mkdir -p "$LOG_DIR"
    if [ "$(echo "$LOG_DIR" | grep '/$')" ]; then LOG_SERVER="${LOG_DIR}${LOG_FILE}"
	else LOG_SERVER="$LOG_DIR/$LOG_FILE"; fi
else
    LOG_SERVER=/dev/null
fi
cd "$GAMEDIR"

AVG_LOAD="unknown"; SER_SITUATION="unknown"; CHECK_AVG_LOAD_M=0
if [ -e "/proc/loadavg" ]; then CHECK_AVG_LOAD_M=1
    elif [  "$(which sysctl 2>/dev/null)" != "" ]; then CHECK_AVG_LOAD_M=2; fi
while true; do
    if [ -f "$LOG_SERVER" ]; then mv -f "$LOG_SERVER" "$LOG_SERVER.1"; fi
    if [ -e "core" ]; then mv -f "core" "core.1"; fi
    date > "$LOG_SERVER"
    while true; do
	if [ "$CHECK_AVG_LOAD_M" -eq "1" ]; then
	    AVG_LOAD="$(awk '{print $2}' /proc/loadavg)"
	elif [  "$CHECK_AVG_LOAD_M" -eq "2" ]; then
	    AVG_LOAD="$(sysctl -n vm.loadavg | awk -F '{' '{print $2}'  | awk '{print $2}')"
	fi
	if [ "$AVG_LOAD" != "unknown" ]; then
		SER_SITUATION="$(echo "$AVG_LOAD $MAX_LOAD" | awk '{if ($1 > $2) print "highload"}')"
	fi
	if [ "$SER_SITUATION" = "highload" ]; then
	    if [ "$OLD_SER_SITUATION_STATUS" = "" ]; then
		echo "WARNING: Detected high load on the server." >&2
		OLD_SER_SITUATION_STATUS="yes"
	    fi
	    sleep 5m; sleep "$((RANDOM % 180))"s
	else
	    OLD_SER_SITUATION_STATUS=""
	    if [ "$SERVERCOUNT" -ne "0" ] && [ "$SERVERCOUNT" -ne "1" ] && [ "$MASTER_SERVER" != "" ] && [ "$SERVER_GREP_IP" != "" ]; then
		NUM_O_FREE_SER="$(curl -s -L "$CLEAR_M_SERVER" | grep '^\([^|]*|\)\{4\}'"$SERVER_GREP_IP"'|.*$' \
		    | grep '^\([^|]*|\)\{11\}'"$PORT_FD"'' | grep '^\([^|]*|\)\{13\}0|.*$' | wc -l)"
	    else
		NUM_O_FREE_SER=""
	    fi
	    if [ "$NUM_O_FREE_SER" != "" ] && [ "$NUM_O_FREE_SER" -ge "$NUM_OA_SERVERS" ]; then
		if [ "$OLD_NUM_OFS_STATUS" = "" ]; then
		    echo "Notice: Waiting for situation when server may be really needed." >&2
		    OLD_NUM_OFS_STATUS="yes"
		fi
		sleep 2m; sleep "$((RANDOM % 60))"s
	    else
		OLD_NUM_OFS_STATUS=""
		break
	    fi
	fi
    done

    if [ "$SERVERCOUNT" -eq "1" ] && [ ! -e "$GAMEDIR/${SHORT_GAME_NAME}-mini-update.sh" ] && \
	[ -e "$GAMEDIR/../${SHORT_GAME_NAME}-dev_version-update.sh" ]; then
	if [ ! -f "$GAMEDIR/${SHORT_GAME_NAME}-dev_version-update-done.log" ]; then
	    echo "... dev_version update:" >&2
	    "$GAMEDIR/../${SHORT_GAME_NAME}-dev_version-update.sh" "$GAMEDIR"; sleep 1s
	    echo "#" > "$GAMEDIR/${SHORT_GAME_NAME}-dev_version-update-done.log"; sleep 1s
	    "$GAMEDIR/$SERVER_SCRIPT" $@ &
	    break
	else
	    rm -f "$GAMEDIR/${SHORT_GAME_NAME}-dev_version-update-done.log"
	fi
    fi
    echo 'Starting server...' | tee -a "$LOG_SERVER"

    if [ "$MASTER_SERVER" != "" ] && [ "$SERVER_GREP_IP" != "" ]; then
	( check_nr=0; force_restart=0; loop_start="yes"; BeginTime="$(date +"%s")"; sleep 4m
	while true; do
	    SER_PID="$(ps -ef | grep "$SER_GREP_PARAMETERS" | awk '/\/'"$EXC_BINARY"' / {print $2}')"
	    if [ "$loop_start" = "yes" ]; then SER_PID_S="$SER_PID"; loop_start="no"; fi
	    CheckTime="$(date +"%s")"; DiffTime="$(($CheckTime-$BeginTime))"
	    if [ "$SER_PID" != "" ] && [ "$SER_PID" = "$SER_PID_S" ]; then
		FIND_SER="$(curl -s -L "$CLEAR_M_SERVER" | grep '^\([^|]*|\)\{4\}'"$SERVER_GREP_IP"'|.*$' \
		    | grep '^\([^|]*|\)\{11\}'"$PORT"'|.*$')"
		if [ "$FIND_SER" = "" ]; then
		    if [ "$OLD_FIND_SER_STATUS" = "" ]; then
			echo "WARNING: The master server doesn't see this server." >&2
			OLD_FIND_SER_STATUS="yes"
		    fi
		else
		    OLD_FIND_SER_STATUS=""
		    SER_STATUS="$(echo "$FIND_SER" | awk -F '|' '{print $14}')"
		    if [ "$SER_STATUS" = "" ] || [ "$(echo "$SER_STATUS" | grep '^[0-9]\+$')" = "" ]; then
			echo "ERROR: Server status cannot be determined." >&2
		    fi
		fi
		if [ "$SER_STATUS" != "2" ] && [ "$DiffTime" -gt "43200" ]; then
		    echo "Notice: The server is working continuously for over 12 hours." >&2; force_restart=1
		elif [ "$SER_STATUS" = "2" ]; then
		    if [ "$OLD_PROG_STATUS" = "" ]; then
			echo "Status: Game in progress..." >&2
			OLD_PROG_STATUS="yes"; BeginTime2="$(date +"%s")"
		    fi
		    DiffTime2="$(($CheckTime-$BeginTime2))"
		    if [ "$DiffTime2" -gt "14400" ]; then
			echo "WARNING: The game is in progress for over 4 hours." >&2; force_restart=1
		    else
			sleep 8m
		    fi
		elif [ "$SER_STATUS" = "1" ]; then
		    if [ "$OLD_READY_STATUS" = "" ]; then
			OLD_READY_STATUS="yes"; BeginTime3="$(date +"%s")"
		    fi
		    DiffTime3="$(($CheckTime-$BeginTime3))"
		    if [ "$DiffTime3" -gt "3600" ]; then
			echo "WARNING: The game seems to waiting for start for over an hour." >&2; force_restart=1
		    fi
		else
		    OLD_READY_STATUS=""
		fi
		if [ "$force_restart" -eq "1" ]; then
		    FIND_SER=""; if [ "$check_nr" -lt "120" ]; then check_nr=120; fi
		    if [ "$LOG_DIR" != "" ]; then echo "#" > "$LOG_DIR/${SHORT_GAME_NAME}-server-forced-restart.log"; sleep 2s; fi
		fi
		if [ "$FIND_SER" = "" ]; then
		    check_nr="$(($check_nr + 1))"
		    if [ "$check_nr" -lt "119" ]; then :
		    elif [ "$check_nr" -eq "119" ] && [ "$force_restart" -ne "1" ]; then
			echo "ERROR: The master server doesn't see this server for over 4 hours." >&2
		    elif [ "$check_nr" -ge "123" ]; then kill -9 "$SER_PID"
		    else kill "$SER_PID"; fi
		else
		    check_nr=0
		fi
		sleep 2m
	    else
		break
	    fi
	done
	) &
    fi
    "$SERVER_EXEC" $SER_PARAMETERS >> "$LOG_SERVER" 2>&1
    if [ "$?" -ne "0" ]; then
	if [ ! -f "$LOG_DIR/${SHORT_GAME_NAME}-server-forced-restart.log" ]; then
	    echo 'ERROR: Server has quit unexpectedly.' >> "$LOG_SERVER"
	    echo 'ERROR: Server has quit unexpectedly.' >&2
	    if [ "$SERVERCOUNT" -eq "0" ]; then
		echo '       Please inspect '"$LOG_SERVER"'.' >&2
		exit 1
	    fi
	    sleep 5s
	    if [ "$SERVERCOUNT" -eq "1" ] && [ "$SERVER_GREP_IP" != "" ] && [ -e "$GAMEDIR/${SHORT_GAME_NAME}-mini-update.sh" ]; then
		echo "... attempt to perform mini update, which may solve tiny problems:" >&2
		"$GAMEDIR/${SHORT_GAME_NAME}-mini-update.sh"; sleep 1s
	    fi
	else
	    echo 'Notice: Server was restarted by script.' >> "$LOG_SERVER"
	    rm -f "$LOG_DIR/${SHORT_GAME_NAME}-server-forced-restart.log"
	fi
	sleep "$((RANDOM % 30))"s
    else
	echo 'Server has quit.' | tee -a "$LOG_SERVER"
    fi
done