#!/bin/sh -u
#
# Output a BOM 128km rain radar image in PNG form, usually transparent.
#       - Cameron Simpson <cs@zip.com.au> 15jan2007
#

: ${TMPDIR:=/tmp}

dotrans=1

cmd=`basename "$0"` || exit 1
usage="usage: $cmd [-notrans] image
        -notrans        Do not create transparency of the sea and land.
        image           Image to fetch."

badopts=

[ $# -gt 0 ] && [ "x$1" = x-notrans ] && { dotrans=; shift; }
if [ $# = 0 ]
then
  echo "$cmd: missing image" >&2
  badopts=1
else
  image=$1
  shift
  [ $# -gt 0 ] && { echo "$cmd: extra arguments after image: $*" >&2
                    badopts=1
                  }
fi

[ $badopts ] && { echo "$usage" >&2; exit 2; }

case "$image" in
  http://*)
    ;;
  *)image=http://mirror.bom.gov.au/radar/$image?x
    ;;
esac

if [ $dotrans ]
then
  tmpf=$TMPDIR/$cmd$$.png
  trap 'rm -f "$tmpf"' 0 1 2 13 15
else
  tmpf=png:-
fi

wget -q -O - "$image" | gm convert GIF:- -crop 512x496+6+22 "$tmpf" || exit 1
[ $dotrans ] || exit 0
bom-radar-trans "$tmpf"