#!/bin/sh

DAEMON=transmission
DAEMON_BIN="$DAEMON-daemon"
PID_FILE=/var/run/$DAEMON.pid
. /etc/init.d/modlibrc

USERNAME=bittorrent
GROUPNAME=users

echoFailedAndExit() {
	echo 'failed.'
	[ -n "$1" ] && exit $1 || exit 1
}

checkNotEmpty() {
	if [ -z "$1" ]; then
		[ -n "$2" ] && echo -e "\n$2 must not be empty."
		echoFailedAndExit 255
	fi
}

checkDirectoryExists() {
	if [ ! -d "$1" ]; then
		echo -e "\n'$1' doesn't exist. Creating directory."
		mkdir -p "$1" || echoFailedAndExit 255
	fi
}

trim() {
	echo "$1" | sed 's|^[ ]*||;s|[ ]*$||'
}

stripAllSpaces() {
	echo "${1// /}"
}

start() {
	echo -n 'Starting transmission daemon ... '

	TRANSMISSION_BASEDIR=$(trim "$TRANSMISSION_BASEDIR")
	TRANSMISSION_CONFIGDIR=$(trim "$TRANSMISSION_CONFIGDIR")
	TRANSMISSION_DOWNLOADDIR=$(trim "$TRANSMISSION_DOWNLOADDIR")
	TRANSMISSION_INCOMPLETEDIR=$(trim "$TRANSMISSION_INCOMPLETEDIR")
	TRANSMISSION_FINISHDIR=$(trim "$TRANSMISSION_FINISHDIR")
	TRANSMISSION_WEBDIR=$(trim "$TRANSMISSION_WEBDIR")
	TRANSMISSION_WATCHDIR=$(trim "$TRANSMISSION_WATCHDIR")

	checkNotEmpty "$TRANSMISSION_CONFIGDIR" 'TRANSMISSION_CONFIGDIR'
	checkNotEmpty "$TRANSMISSION_DOWNLOADDIR" 'TRANSMISSION_DOWNLOADDIR'
	if [ "${TRANSMISSION_CONFIGDIR:0:1}" != "/" -o "${TRANSMISSION_DOWNLOADDIR:0:1}" != "/" ]; then
		checkNotEmpty "$TRANSMISSION_BASEDIR" 'TRANSMISSION_BASEDIR'
		if [ ${TRANSMISSION_BASEDIR:0:1} != "/" ]; then
			echo -e "\nTRANSMISSION_BASEDIR must be an absolute path."
			echoFailedAndExit 255
		fi

		checkDirectoryExists "$TRANSMISSION_BASEDIR"

		if [ "${TRANSMISSION_BASEDIR:$((${#TRANSMISSION_BASEDIR}-1)):1}" != "/" ]; then
			# add trailing slash in case it is missing
			TRANSMISSION_BASEDIR="$TRANSMISSION_BASEDIR/"
		fi
	fi

	[ ${TRANSMISSION_CONFIGDIR:0:1} = "/" ] && CONFIGDIR="$TRANSMISSION_CONFIGDIR" || CONFIGDIR="$TRANSMISSION_BASEDIR$TRANSMISSION_CONFIGDIR"
	checkDirectoryExists "$CONFIGDIR"

	[ ${TRANSMISSION_DOWNLOADDIR:0:1} = "/" ] && DOWNLOADDIR="$TRANSMISSION_DOWNLOADDIR" || DOWNLOADDIR="$TRANSMISSION_BASEDIR$TRANSMISSION_DOWNLOADDIR"
	checkDirectoryExists "$DOWNLOADDIR"

	local OPTIONS="--no-portmap"

	if [ -n "$TRANSMISSION_INCOMPLETEDIR" ]; then
		[ ${TRANSMISSION_INCOMPLETEDIR:0:1} = "/" ] && INCOMPLETEDIR="$TRANSMISSION_INCOMPLETEDIR" || INCOMPLETEDIR="$TRANSMISSION_BASEDIR$TRANSMISSION_INCOMPLETEDIR"
		checkDirectoryExists "$INCOMPLETEDIR"
		chown -R $USERNAME:$GROUPNAME "$INCOMPLETEDIR"
		OPTIONS="$OPTIONS --incomplete-dir $INCOMPLETEDIR"
	else
		OPTIONS="$OPTIONS --no-incomplete-dir"
	fi

	if [ -n "$TRANSMISSION_FINISHDIR" ]; then
		[ ${TRANSMISSION_FINISHDIR:0:1} = "/" ] && FINISHDIR="$TRANSMISSION_FINISHDIR" || FINISHDIR="$TRANSMISSION_BASEDIR$TRANSMISSION_FINISHDIR"
		checkDirectoryExists "$FINISHDIR"
		chown -R $USERNAME:$GROUPNAME "$FINISHDIR"
		OPTIONS="$OPTIONS --finish-dir $FINISHDIR"
	else
		OPTIONS="$OPTIONS --no-finish-dir"
	fi

	chown -R $USERNAME:$GROUPNAME "$CONFIGDIR" "$DOWNLOADDIR"

	if [ -n "$TRANSMISSION_WATCHDIR" ]; then
		[ ${TRANSMISSION_WATCHDIR:0:1} = "/" ] && WATCHDIR="$TRANSMISSION_WATCHDIR" || WATCHDIR="$TRANSMISSION_BASEDIR$TRANSMISSION_WATCHDIR"
		checkDirectoryExists "$WATCHDIR"
		chown -R $USERNAME:$GROUPNAME "$WATCHDIR"
		OPTIONS="$OPTIONS --watch-dir $WATCHDIR"
	fi

	[ -n "$TRANSMISSION_PEERPORT" ] && OPTIONS="$OPTIONS -P $TRANSMISSION_PEERPORT"
	[ -n "$TRANSMISSION_GLOBALPEERLIMIT" ] && OPTIONS="$OPTIONS -L $TRANSMISSION_GLOBALPEERLIMIT"
	[ -n "$TRANSMISSION_TORRENTPEERLIMIT" ] && OPTIONS="$OPTIONS -l $TRANSMISSION_TORRENTPEERLIMIT"
	if [ "$TRANSMISSION_PEERENCRYPTIONMODE" = "ENCRYPTION_REQUIRED" ]; then
		OPTIONS="$OPTIONS -er"
	elif [ "$TRANSMISSION_PEERENCRYPTIONMODE" = "ENCRYPTION_PREFERRED" ]; then
		OPTIONS="$OPTIONS -ep"
	else
		OPTIONS="$OPTIONS -et"
	fi
	[ "$TRANSMISSION_USEBLOCKLIST" = "yes" ] && OPTIONS="$OPTIONS -b" || OPTIONS="$OPTIONS -B"
	[ "$TRANSMISSION_USEDHT" = "yes" ] && OPTIONS="$OPTIONS --dht" || OPTIONS="$OPTIONS --no-dht"
	[ "$TRANSMISSION_USEUTP" = "yes" ] && OPTIONS="$OPTIONS --utp" || OPTIONS="$OPTIONS --no-utp"

	# Set utp-receive & -send buffer sizes. Do it always as the utp-option could be changed via transmission's web-interface.
	# NB: the values here must correspond to those from libtransmission/tr-udp.c
	local RECV_BUFFER_SIZE=$((2 * 1024 * 1024))
	local SEND_BUFFER_SIZE=$((     512 * 1024))
	echo $RECV_BUFFER_SIZE > /proc/sys/net/core/rmem_max
	echo $RECV_BUFFER_SIZE > /proc/sys/net/core/rmem_default
	echo $SEND_BUFFER_SIZE > /proc/sys/net/core/wmem_max
	echo $SEND_BUFFER_SIZE > /proc/sys/net/core/wmem_default

	if [ -n "$TRANSMISSION_RPCUSERNAME" -a -n "$TRANSMISSION_RPCPASSWORD" ]; then
		OPTIONS="$OPTIONS --auth --username $TRANSMISSION_RPCUSERNAME --password $TRANSMISSION_RPCPASSWORD"
	else
		OPTIONS="$OPTIONS --no-auth"
		echo -n "without password protection ... "
	fi

	[ -n "$TRANSMISSION_RPCPORT" ] && OPTIONS="$OPTIONS -p $TRANSMISSION_RPCPORT"
	TRANSMISSION_RPCWHITELIST=$(stripAllSpaces "$TRANSMISSION_RPCWHITELIST")
	[ -n "$TRANSMISSION_RPCWHITELIST" ] && OPTIONS="$OPTIONS -a $TRANSMISSION_RPCWHITELIST"
	[ -n "$TRANSMISSION_RATIO" ] && OPTIONS="$OPTIONS --global-seedratio $TRANSMISSION_RATIO" || OPTIONS="$OPTIONS --no-global-seedratio"
	[ -n "$TRANSMISSION_LOGLEVEL" ] && OPTIONS="$OPTIONS --log-$TRANSMISSION_LOGLEVEL"

	if [ -n "$TRANSMISSION_WEBDIR" -a -d "$TRANSMISSION_WEBDIR" -a -r "$TRANSMISSION_WEBDIR/index.html" ]; then
		export TRANSMISSION_WEB_HOME="$TRANSMISSION_WEBDIR"
	else
		echo -n "without web interface ... "
		unset TRANSMISSION_WEB_HOME
	fi

	[ ! -e $PID_FILE ] && echo -n > $PID_FILE
	chown $USERNAME:$GROUPNAME $PID_FILE
	start-stop-daemon \
		-S \
		-N "$TRANSMISSION_NICE" \
		-x "$DAEMON_BIN" \
		-c "$USERNAME:$GROUPNAME" \
		-- \
		$OPTIONS --config-dir "$CONFIGDIR" --download-dir "$DOWNLOADDIR" --pid-file "$PID_FILE" \
		>/dev/null

	exitval=$?
	[ "$exitval" -eq 0 ] && echo 'done.' || echoFailedAndExit "$exitval"
}

case $1 in
	""|load)
		modlib_add_user_and_group $USERNAME $GROUPNAME
		modreg cgi 'transmission' 'Transmission'
		modreg daemon $DAEMON

		modlib_start $TRANSMISSION_ENABLED
		;;
	unload)
		modunreg daemon $DAEMON
		modunreg cgi 'transmission'
		modlib_stop
		;;
	start)
		modlib_start
		;;
	stop)
		modlib_stop
		;;
	restart)
		modlib_restart
		;;
	reload)
		modlib_reload
		;;
	status)
		modlib_status
		;;
	*)
		echo "Usage: $0 [load|unload|start|stop|restart|reload|status]" 1>&2
		exit 1
		;;
esac

exit 0