#!/bin/sh

# Format of Moongiant.com query  
#      http://www.moongiant.com/phase/MM/DD/YYYY


# if no date specified, just use "today":

if [ $# -eq 0 ] ; then
  thedate="today"
else
  # date specified. Let's check to see if it's in the right format
   mon="$(echo $1 | cut -d/ -f1)"
   day="$(echo $1 | cut -d/ -f2)"
  year="$(echo $1 | cut -d/ -f3)"

  if [ -z "$year" -o -z "$day" ] ; then	    # zero length?
    echo "Error: only valid date format is MM/DD/YYYY"
    exit 1
  fi
  
  # You could add additional date checking code here, or invoke
  # the earlier script checkdate

  thedate="$1" # no error checking = dangerous
fi

echo checking moon phase for day = $thedate

url="http://www.moongiant.com/phase/$thedate"
pattern="Illumination:"

phase="$( curl -s "$url" | grep "$pattern" | tr ',' '\
' | grep "$pattern" | sed 's/[^0-9]//g')"

# format from this is     "Illumination: <span>74%\n<\/span>"

if [ "$thedate" = "today" ] ; then
  echo "Today the moon is ${phase}% illuminated."
else
  echo "On $thedate the moon = ${phase}% illuminated."
fi

exit 0