#!/bin/bash
# Present -- show a dzen2 countdown and present via evince.
# (c) 2010 Marco Fontani - MFONTANI at cpan dot org
# Usage: present MINS SECS FILE
set -bm
COLOR='#444444'
function countdown () {
    seq 1 ${1:-10} | tac | \
        perl -ne'BEGIN{$|++;$msg=shift}$m=int($_/60);$s=int($_-$m*60);printf("$m:%02d -- $msg\n",$s);sleep 1;' \
        "${2:-ready...}"
}
function countdown_cleanup () {
    pkill dzen2
    exit
}
NMINS=$1
if [ -z "$NMINS" ]; then
    echo "$0 MINS SECS PDF FILE"
    exit 1
fi
NSECS=${2}
if [ -z "$NSECS" ]; then
    echo "$0 MINS SECS PDF FILE"
    exit 1
fi
FILE=$3
if [ -z "$FILE" ]; then
    echo "Need a filename too"
    exit 1
fi
if [ ! -f "$FILE" ]; then
    echo "Need an _existing_ filename too"
    exit 1
fi
TOTSECS=$(echo "$NMINS*60+$NSECS" | bc)
countdown 5 "Ready for $NMINS mins $NSECS secs ($TOTSECS)" | dzen2 -fg "$COLOR"
trap 'countdown_cleanup' SIGCHLD
evince -s $FILE &
countdown "$TOTSECS" "GO" | dzen2 -fg "$COLOR"