# Originally by Wael Nasreddine <wael@phoenixlinux.org>.
#
# Made a standalone script for usage with xmonad by Patrick Hof
# <patrickhof@web.de>
# Last Change: 2007-12-22

class Battery

  STATEFILE = '/proc/acpi/battery/BAT0/state'
  INFOFILE =  '/proc/acpi/battery/BAT0/info'
  LOW =  5
  LOW_ACTION = 'echo "Low battery" | xmessage -center -buttons quit:0 -default quit -file -'
  CRITICAL = 1
  CRITICAL_ACTION = 'echo "Critical battery" | xmessage -center -buttons quit:0 -default quit -file -'

  def initialize
    @warned_low = false
    @warned_critical = false
  end

  def battery
    batt = IO.readlines(STATEFILE)
    battinfo = IO.readlines(INFOFILE)
    battpresent = battinfo[0].gsub(/.*:\s*/,'').chomp
    if battpresent == "yes"
      bat_a = batt[4].gsub(/.*:\s*/,'').chomp.chomp("mAh").to_f
      bat_b = battinfo[2].gsub(/.*:\s*/,'').chomp.chomp(" mAh").to_f 
      batt_percent = ((bat_a / bat_b) * 100).to_i
      batt_state = batt[2].gsub(/.*:\s*/,'').chomp
      # Take action in case battery is low/critical
      if batt_state == "discharging" && batt_percent <= CRITICAL
        unless @warned_critical
          system("ssid #{CRITICAL_ACTION} &")
          @warned_critical = true
        end
      elsif batt_state == "discharging" && batt_percent <= LOW
        unless @warned_low
          system("ssid #{LOW_ACTION} &")
          @warned_low = true
        end
      else
        @warned_low = false
        @warned_critical = false
      end
      # If percent is 100 and state is discharging then
      # the battery is full and not discharging.
      batt_state = "=" if batt_state == "charged" || ( batt_state == "discharging" && batt_percent >= 97 )
      batt_state = "^" if batt_state == "charging"
      batt_state = "v" if batt_state == "discharging"
      text = "#{batt_state} #{batt_percent} #{batt_state}"
      return text
    else
      return "N/A"
    end
  end
end