#!/bin/bash

############################################################
# Battery charge.

BATTERY=C1B2 ### <- Battery ID

cat /proc/acpi/battery/${BATTERY}/state | grep ' charged' 2>&1 >/dev/null && TIME_LEFT="" || DO_BATTERY=1

if [[ -n ${DO_BATTERY} ]]; then
  CHARGE_REMAINING=`cat /proc/acpi/battery/${BATTERY}/state | grep "remaining capacity" | awk '{print $3}'`
  DISCHARGE_RATE=`cat /proc/acpi/battery/${BATTERY}/state | grep "present rate" | awk '{print $3}'`
  [[ $DISCHARGE_RATE -ne 0 ]] && ((HOURS_LEFT=${CHARGE_REMAINING}/${DISCHARGE_RATE}))
  MINUTES_LEFT=`echo "scale=2; ((${CHARGE_REMAINING}/${DISCHARGE_RATE})-${HOURS_LEFT})*0.6" | bc`
  cat /proc/acpi/battery/${BATTERY}/state | grep ' charging' 2>&1 >/dev/null && TIME_LEFT="[Charging] · " || TIME_LEFT="-${HOURS_LEFT}${MINUTES_LEFT}h · "
fi

############################################################
# CPU Usage

B=( `cat /proc/stat | head -n1 | gawk '{print $2 " " $3 " " $4 " " $5}'` )
sleep 2s; # Sample some real CPU usage time...
E=( `cat /proc/stat | head -n1 | gawk '{print $2 " " $3 " " $4 " " $5}'` )

UPTIME=`echo "(100*((${E[0]}-${B[0]})+(${E[1]}-${B[1]})+(${E[2]}-${B[2]})))/((${E[0]}-${B[0]})+(${E[1]}-${B[1]})+(${E[2]}-${B[2]})+(${E[3]}-${B[3]}))" | bc`
UPTIME="${UPTIME}%"

############################################################
# Tkabber UNREAD messages

NUMBER=$(xprop -id `xwininfo -root -children 2>/dev/null | grep Tkabber | awk '{print $1}'` 2>/dev/null | grep 'WM_NAME(STRING) = "(' | sed 's/^.*"(//;s/\*.*$//')
[[ ${NUMBER} -ge 1 ]] && TKABBER="Tkabber: ${NUMBER} · "

############################################################
# Wireless status (ESSID and percentage)

INTERFACE=eth2

ESSID=`iwconfig 2>/dev/null | grep "^${INTERFACE}" | sed -r 's/^.*ESSID:"([A-Za-z0-9\-]+).*$/\1/'`
STRENGTH=`iwconfig 2>/dev/null | grep 'Link Quality' | sed -r 's/^.*Link Quality.([[:digit:]]+).*$/\1%/'`
[[ "${ESSID}" != "${INTERFACE}      radio off  ESSID:off/any  " && "${STRENGTH}" != "0%" ]] && WIRELESS="${ESSID} ${STRENGTH} · "

############################################################
# Date

DATE="`date '+%H:%M:%S, %a %d/%m/%y'` · "

############################################################
# All put together

STATUS="${TKABBER}${TIME_LEFT}${WIRELESS}${DATE}${UPTIME}"
echo ${STATUS} > .dwm-status