#!/bin/bash
wifi="/tmp/$$-wifi.icon"

# Set up tray icon
mkfifo $wifi
mktrayicon $wifi 2>/dev/null &
echo "h" > $wifi
run=1

trap 'run=0' INT;
while [[ $run -eq 1 ]]; do
  # See network-manager:wifi:wext_qual_to_percent
  # http://cgit.freedesktop.org/NetworkManager/NetworkManager/tree/src/wifi/wifi-utils-wext.c#n264
  qual=`iwconfig 2>/dev/null | grep "Link Quality" | sed 's/.*Link Quality=\([0-9]*\/[0-9]*\) .*/\1/'`
  if [[ -n $qual ]]; then
    qual=`echo "100*$qual" | bc`
    if ((qual<25)); then
      echo "i network-wireless-signal-weak-symbolic" > $wifi;
      echo "t Weak ($qual%)" > $wifi;
    elif ((qual<50)); then
      echo "i network-wireless-signal-ok-symbolic" > $wifi;
      echo "t OK ($qual%)" > $wifi;
    elif ((qual<75)); then
      echo "i network-wireless-signal-good-symbolic" > $wifi;
      echo "t Good ($qual%)" > $wifi;
    else
      echo "i network-wireless-signal-excellent-symbolic" > $wifi;
      echo "t Excellent ($qual%)" > $wifi;
    fi

    echo "s" > $wifi;
  else
    echo "h" > $wifi;
  fi

  sleep 30
done

# Remove tray icon
echo "q" > $wifi
rm $wifi