#!/bin/sh -e
#
#    network: calculate the network up/down rates
#    Copyright (C) 2008 Canonical Ltd.
#
#    Authors: Dustin Kirkland <kirkland@canonical.com>
#
#    This program is free software: you can redistribute it and/or modify
#    it under the terms of the GNU General Public License as published by
#    the Free Software Foundation, version 3 of the License.
#
#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU General Public License for more details.
#
#    You should have received a copy of the GNU General Public License
#    along with this program.  If not, see <http://www.gnu.org/licenses/>.

PKG="byobu"
color 2>/dev/null || color() { true; }

# Allow interface overrides in $HOME/.$PKG/status
if [ -n "$MONITORED_NETWORK" ]; then
	interface="$MONITORED_NETWORK"
else
	interface=`tail -n1 /proc/net/route  | awk '{print $1}'`
fi

if [ "$1" = "--detail" ]; then
	/sbin/ifconfig "$interface" | sed 's/\s*$//'
	exit 0
fi

[ -d "/var/run/screen/S-$USER" ] && DIR="/var/run/screen/S-$USER" || DIR="$HOME/.byobu"
t2=`date +%s`
for i in up down; do
	cache="$DIR/$PKG.network_$i"
	t1=`stat -c %Y "$cache"` 2>/dev/null || t1=0
	unit="kB/s"
	if [ $t2 -le $t1 ]; then
		rate=0
	else
		x1=`cat "$cache"` 2>/dev/null || tx1=0
		if [ "$i" = "up" ]; then
			symbol="^"
			x2=`grep -m1 "\b$interface:" /proc/net/dev | sed "s/^.*://" | awk '{print $9}'`
		else
			symbol="v"
			x2=`grep -m1 "\b$interface:" /proc/net/dev | sed "s/^.*://" | awk '{print $1}'`
		fi
		echo "$x2" > "$cache"
		rate=`echo "$t1" "$t2" "$x1" "$x2" | awk '{printf "%.0f", ($4 - $3) / ($2 - $1) / 1024 }'`
		if [ "$rate" -lt 0 ]; then
			rate=0
		elif [ "$rate" -gt 1024 ]; then
			rate=`echo "$rate" | awk '{printf "%.1f", $1/1024}'`
			unit="MB/s"
		fi
	fi
	printf "$symbol$(color b m w)$rate$(color -)$(color m w)$unit$(color -) "
done