#!/bin/sh -e
#
#    mem_available: grab the current memory and usage
#
#    Copyright (C) 2008 Canonical Ltd.
#    Copyright (C) 2011-2014 Dustin Kirkland
#
#    Authors: Dustin Kirkland <kirkland@byobu.org>
#
#    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/>.

__memory_detail() {
	free
}

__memory() {
	local free="" total="" buffers="" cached=""
	local kb_main_used=0 buffers_plus_cached=0 fo_buffers=0 fo_cached=0
	if [ -r /proc/meminfo ]; then
		while read tok val unit; do
			case "$tok" in
				MemTotal:) total=${val};;
				MemFree:) free=${val};;
				Buffers:) buffers=${val};;
				Cached:) cached=${val};;
			esac
			[ -n "${free}" -a -n "${total}" -a -n "${buffers}" -a -n "${cached}" ] && break;
		done < /proc/meminfo
	elif eval $BYOBU_TEST vm_stat >/dev/null 2>&1; then
		# MacOS support
		# calculation borrowed from http://apple.stackexchange.com/a/48195/18857
		free_blocks=$(vm_stat | grep free | awk '{ print $3 }' | sed -e 's/\.//')
		inactive_blocks=$(vm_stat | grep inactive | awk '{ print $3 }' | sed -e 's/\.//')
		speculative_blocks=$(vm_stat | grep speculative | awk '{ print $3 }' | sed -e 's/\.//')
		free=$((($free_blocks+speculative_blocks)*4))
		inactive=$(($inactive_blocks*4))
		total=$((($free+$inactive)))
		buffers=0
		cached=0
	fi
        kb_main_used=$(($total-$free))
        buffers_plus_cached=$(($buffers+$cached))
        # "free output" buffers and cache (output from 'free')
        fo_buffers=$(($kb_main_used - $buffers_plus_cached))
        fpdiv $((100*${fo_buffers})) "${total}" 0;
        usage=${_RET}
	if [ $total -ge 1048576 ]; then
		fpdiv "$total" 1048567 1
		total=${_RET}
		unit="$ICON_GB"
	elif [ $total -ge 1024 ]; then
		fpdiv "$total" 1024 0
		total=${_RET}
		unit="$ICON_MB"
	else
		unit="$ICON_KB"
	fi
	if [ $usage -gt 90 ]; then
		# Change foreground to yellow, if usage over 90%
		fg="Y"
	else
		fg="W"
	fi
	[ -n "$total" ] || return
	color b g W; printf "%s" "$total"; color -; color g W; printf "%s" "$unit"; color -; color b g "$fg"; printf "%s" "$usage"; color -; color g "$fg"; printf "%s" "$PCT"; color --
}

# vi: syntax=sh ts=4 noexpandtab