#!/bin/bash
#
##############################################################################
#
# countdown : bash script to visually count down a specified number of seconds
#
##############################################################################
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
#
##############################################################################
#
MY_NAME=countdown
MY_VERSION=1.1
MY_RELDATE=2000-07-06
MY_AUTHOR_NAME="Roy Batty"
MY_AUTHOR_MAIL="roybatty@altavista.net"
#
##############################################################################
#
STAMP=/tmp/.stamp.$USER.$$
#
function init_timer() {
  [ -f $STAMP.stop ] && rm -f $STAMP.stop 2>/dev/null
  echo S=`date +%s` >$STAMP
}
function run_timer() {
  while [ ! -f $STAMP.stop ]; do
    echo S=`date +%s` >$STAMP
    sleep 1
  done
  rm -f $STAMP $STAMP.stop
}
function stop_timer() {
  touch $STAMP.stop
}
function clean_exit() {
  stop_timer
  echo " "
  echo "Terminated."
  mpv $HOME/.bin/Alarmclock-mechanical.ogg
  trap "" 0 1 3 5 9 15
  exit 0
}
function syntax_error() {
  cat <<-EOF 1>&2

	$MY_NAME $MY_VERSION ($MY_RELDATE) - bash script to visually count down
	Copyright 2000: $MY_AUTHOR_NAME <$MY_AUTHOR_MAIL>
	Usage:

	$0 [[h] m] s
          counts down h hours, m minutes and s seconds

	EOF
  exit 1
}
function get_diff() {
  let DIFF=0
  [ "$1" = "" -o "$4" != "" ] && syntax_error
  while [ "$1" != "" ]; do
    let p=0
    [ "$1" != "0" ] && ! let p=$1 2>/dev/null && syntax_error
    [ $p -lt 0 ] && syntax_error
    let DIFF=$DIFF*60+$p
    shift
  done
}
function display_nice() {
  local s=$1; local h=0; local m=0; ni=""
  [ $s -ge 3600 ] && let h=$[ s/3600 ] && let s=$[ s%3600 ]
  [ $s -ge 60 ]   && let m=$[ s/60 ]   && let s=$[ s%60 ]
  [ $h -lt 10 ] && ni="0";      ni="$ni$h:"
  [ $m -lt 10 ] && ni="${ni}0"; ni="$ni$m:"
  [ $s -lt 10 ] && ni="${ni}0"; ni="$ni$s"
  echo -n "$ni"
}
#
# main script
#
get_diff $*
trap clean_exit 0 1 3 5 9 15
echo "$MY_NAME $MY_VERSION ($MY_RELDATE) - Counting down `display_nice $DIFF` [hrs:min:sec]"
if [ $DIFF -le 0 ]; then
  echo "Nothing to do." 1>&2
  exit 2
fi
echo " Elapsed  | Remaing. |  Complete"
let START=`date +%s`
declare -a HASH=( [0]=". " [1]="o " [2]="O " [3]="- " )
compl="##################################################"
blank="                                                  "
let ha=0
init_timer
run_timer &
while true; do
  . $STAMP
  let R=$DIFF-$S+$START
  if [ $R -gt 0 ]; then
    echo -n "${HASH[$ha]}`display_nice $[ $DIFF-$R ]` | `display_nice $R` | "
    let P=$[ ($S-$START) * 100 / $DIFF ]
    echo -ne "[${compl:0:P/2}${blank:0:50-P/2}] $P%\r"
  else
    echo -n "${HASH[$ha]}`display_nice $DIFF` | `display_nice 0` | "
    echo -ne "[$compl] 100%\r"
    clean_exit
  fi
  let ha=$[ (ha+1) % 4 ]
  sleep 1
done