#!/bin/sh
#
#    ec2_cost: approximate EC2 cost (USD) of the current instance
#    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/>.

DETAIL=0
PKG="byobu"
color 2>/dev/null || color() { true; }

for arg in $@; do
	case "$arg" in
		-d|--detail)
			DETAIL=1
		;;
	esac
done

# Get the going rates
[ -r "$HOME/.$PKG/ec2_rates" ] || ln -s /usr/share/$PKG/ec2/rates.us_ca "$HOME/.$PKG/ec2_rates"
. "$HOME/.$PKG/ec2_rates" || exit 1

# Count CPUs, Memory, Architecture
cpu=$(grep -c "^processor.*:" /proc/cpuinfo) || cpu=1
mem=$(grep ^MemTotal /proc/meminfo | awk '{print $2}')

# Guess this system's going rate, based on mem available (m* types)
if [ $mem -gt 64000000 ]; then
	RATE=$M2_4XLARGE
elif [ $mem -gt 32000000 ]; then
	RATE=$M2_2XLARGE
elif [ $mem -gt 16000000 ]; then
	RATE=$M2_XLARGE
elif [ $mem -gt 14000000 ]; then
	RATE=$M1_XLARGE
elif [ $mem -gt 7000000 ]; then
	RATE=$M1_LARGE
else
	# Otherwise, scale based on number of cpu's (c* types)
	RATE=$(echo "$cpu" "$M1_SMALL" | awk '{printf "%f", $1*$2}')
fi

# Data Transfer Cost Basis
# Incoming	$0.10/GB
# Outgoing	$0.17/GB
# (This gets more complex if you use >1TB/mo)
RX_RATE="0.10"
TX_RATE="0.15"

# Auto detect network interface
IF=`tail -n1 /proc/net/route  | awk '{print $1}'`

ifconfig_out=`/sbin/ifconfig "$IF"`

# Calculate bandwidth cost
tx_gb=`echo "$ifconfig_out" | grep "TX bytes:" | sed "s/^.*TX bytes://" | awk '{ printf "%f", $1 / 1024 / 1024 / 1024 }'`
rx_gb=`echo "$ifconfig_out" | grep "RX bytes:" | sed "s/^.*RX bytes://" | awk '{ printf "%f", $1 / 1024 / 1024 / 1024 }'`
network_cost=`echo "$tx_gb" "$TX_RATE" "$rx_gb" "$RX_RATE" | awk '{printf "%f %f", $1*$2, $3*$4}' | awk '{printf "%f", $1 + $2}'`

# Calculate uptime cost
# BUG: This will only calculate uptime since boot!
#      Some additional input will be required to account for reboots!!!
hours=`awk '{printf "%f", 1 + $1 / 60 / 60 }' /proc/uptime | sed 's/\..*$//' `
uptime_cost=`echo "$hours" | awk "{printf \"%f\", "$RATE" * $hours}"`
total_cost=`echo "$network_cost" "$uptime_cost" | awk '{printf "%.2f", $1 + $2}'`

if [ "$DETAIL" = "1" ]; then
	echo "================================================"
	echo "Estimated cost in Amazon's EC2 since last reboot"
	echo "================================================"
	echo "  Network sent:  $tx_gb GB   @ \$$RX_RATE/GB"
	echo "  Network recv:  $rx_gb GB   @ \$$TX_RATE/GB"
	echo "  Network cost:  \$$network_cost"
	echo "------------------------------------------------"
	echo "  Uptime:        $hours hr  @ \$$RATE/hr"
	echo "  Uptime cost:   \$$uptime_cost"
	echo "------------------------------------------------"
	echo "Total cost:      ~\$$total_cost"
	echo "================================================"
	exit 0
fi

printf "$(color K G)~\$$(color -)$(color b K G)%s$(color -) " $total_cost