#!/bin/sh -e
#
#    ec2_cost: approximate EC2 cost (USD) of the current instance
#
#    Copyright (C) 2008 Canonical Ltd.
#    Copyright (C) 2011 Dustin Kirkland
#
#    Authors: Dustin Kirkland <kirkland@ubuntu.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/>.

# 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"

__ec2_cost_detail() {
	DETAIL=1
	__ec2_cost
}

__ec2_cost() {
	local zone type file_to_stat cpu mem rate hours tx_gb rx_gb network_cost uptime_cost total_cost interface
	# Try to use metadata service
	if metadata_available; then
		zone=$(wget -q -O - http://169.254.169.254/latest/meta-data/placement/availability-zone)
		if [ ! -r "$BYOBU_PREFIX/share/$PKG/ec2/rates.${zone%?}" ]; then
			zone="us-east-1d"
		fi
		. "$BYOBU_PREFIX/share/$PKG/ec2/rates.${zone%?}"
		type=$(wget -q -O - http://169.254.169.254/latest/meta-data/instance-type | $SED -e "s/\./_/g")
		eval rate="\$$type"
		file_to_stat="$BYOBU_RUN_DIR/cache.$BYOBU_BACKEND/ec2_cost.instance_type"
		[ -f "$file_to_stat" ] || wget -q -O "$file_to_stat" http://169.254.169.254/latest/meta-data/instance-type
	fi
	if [ -z "$rate" ]; then
		. "$BYOBU_PREFIX/share/$PKG/ec2/rates."*
		# Count CPUs, Memory, Architecture, hours
		cpu=$(grep -c "^processor.*:" /proc/cpuinfo) || cpu=1
		mem=$(grep ^MemTotal /proc/meminfo | awk '{print $2}')
		# /etc/hostname gets created at installation (but might get updated...other ideas?)
		file_to_stat="/etc/hostname"
		# Guess this system's going rate, based on mem available (m* types)
		if [ $mem -lt 700000 ]; then
			rate=$t1_micro
		elif [ $mem -gt 64000000 ]; then
			rate=$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*$2}')
		fi
	fi
	hours=$(((`date +%s` - `stat --printf %Y $file_to_stat`) / 60 / 60 + 1))
	# Auto detect network interface
	interface=`tail -n1 /proc/net/route  | awk '{print $1}'`
	ifconfig_out=`LC_ALL=C /sbin/ifconfig "$interface"`
	# Calculate bandwidth cost
	tx_gb=${ifconfig_out#*RX bytes:}
	tx_gb=$(echo ${tx_gb%% *} | awk '{ printf "%f", $1 / 1024 / 1024 / 1024 }')
	rx_gb=${ifconfig_out#*TX bytes:}
	rx_gb=$(echo ${rx_gb%% *} | 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 + $2}'`
	# Calculate uptime cost
	uptime_cost=`echo "$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 "================================================"
		return
	fi
	color K G; printf "A\$"; color -; color b K G; printf "%s" "$total_cost"; color --
}

# vi: syntax=sh ts=4 noexpandtab