#! /usr/bin/env bash

# dvdmovie plays the movie from a video DVD using MPlayer
#
# Copyright (c) 2012-2021 Erik Auerswald <auerswal@unix-ag.uni-kl.de>
#
# Copying and distribution of this file, with or without modification,
# are permitted in any medium without royalty provided the copyright
# notice and this notice are preserved.  This file is offered as-is,
# without any warranty.

# dvdmovie finds the longest title on a DVD and plays it (using MPlayer)
# additional MPlayer options, e.g. -dvd-device ..., can be specified
# per DVD settings can be saved in $HOME/.dvdmovierc
# $HOME/.dvdmovierc consists of lines containing semicolon separated fields
# the fields are (in this order): Disc ID, Movie Title, Track, Options
# every field besides the Disc ID may be empty

# version 2021-02-14-01

set -u

RC="${HOME}/.dvdmovierc"
test -r "$RC" || {
  RC="${XDG_CONFIG_HOME:-$HOME/.config}/dvdmovierc"
  # a relative XDG_CONFIG_HOME must be ignored
  test "${RC:0:1}" = '/' || RC="${HOME}/.config/dvdmovierc"
}
DVDMOVIERC_TITLE=''
DVDMOVIERC_OPTS=''
MPLAYER="${HOME}/bin/mplayer"
test -x "$MPLAYER" || MPLAYER=$(which mplayer 2> /dev/null)
test -x "$MPLAYER" || MPLAYER=$(type mplayer | awk '{print $NF}')
test -x "$MPLAYER" || { echo 'Could not find mplayer, exiting'; exit 1; }
IOPTS='-cache-min 0 -vo null -ao null -frames 0 -really-quiet -identify'
MOPTS='-really-quiet'
DISC='dvd://'

printf -- 'Looking for movie title on DVD, this can take some time...'
DVDMOVIE_ARRAY=($("$MPLAYER" $IOPTS "$@" "$DISC" 2> /dev/null | awk '
	BEGIN {title = 0; len = 0; discid = 0; name = 0}
	/ID_DVD_TITLE_[0-9]+_LENGTH/ {
		gsub("ID_DVD_TITLE_","")
		gsub("_LENGTH="," ")
		split($0,A)
		if(A[2] > len) {title = A[1]; len = A[2]}
	}
	/ID_DVD_DISC_ID=[0-9a-fA-F]+/ {
		split($0,A,"=")
		discid = A[2]
	}
	/ID_DVD_VOLUME_ID=/ {
		split($0,A,"=")
		name = A[2]
	}
	END {printf "%d %.0f %s %s\n", title, len/60, discid, name}
'))
echo 'done.'
DVDMOVIE_TITLE=${DVDMOVIE_ARRAY[0]}
DVDMOVIE_LEN=${DVDMOVIE_ARRAY[1]}
DVDMOVIE_DISCID=${DVDMOVIE_ARRAY[2]}
DVDMOVIE_NAME=${DVDMOVIE_ARRAY[3]}
for ((I=4; I<${#DVDMOVIE_ARRAY[*]}; I+=1)); do
	DVDMOVIE_NAME="$DVDMOVIE_NAME ${DVDMOVIE_ARRAY[$I]}"
done
test "$DVDMOVIE_TITLE" -gt 0 ||
	{ echo 'ERROR: Could not read titles of DVD.' ; exit 1; }
test "$DVDMOVIE_LEN" -gt 0 ||
	{ echo "ERROR: Longest title $DVDMOVIE_TITLE has zero length.";exit 1; }
test "$DVDMOVIE_DISCID" != '0' ||
	echo 'WARNING: Could not determine disc ID of DVD.'
test "$DVDMOVIE_NAME" != '0' || DVDMOVIE_NAME='no name'
echo "Longest title on DVD ${DVDMOVIE_DISCID} ($DVDMOVIE_NAME) is no." \
	"$DVDMOVIE_TITLE ($DVDMOVIE_LEN min.)."
test -r "$RC" && test "$DVDMOVIE_DISCID" != '0' &&
	DVDMOVIERC_NAME="$(grep "^${DVDMOVIE_DISCID}" "$RC" | cut -d\; -f2)" &&
	DVDMOVIERC_TITLE="$(grep "^${DVDMOVIE_DISCID}" "$RC" | cut -d\; -f3)" &&
	DVDMOVIERC_OPTS="$(grep "^${DVDMOVIE_DISCID}" "$RC" | cut -d\; -f4)"
test "$DVDMOVIE_DISCID" != '0' && test -n "$DVDMOVIERC_NAME" &&
	echo "Found $RC entry '$DVDMOVIERC_NAME'."
test "$DVDMOVIE_DISCID" != '0' && test -n "$DVDMOVIERC_TITLE" &&
	echo "Using title $DVDMOVIERC_TITLE from $RC instead of longest." &&
	DVDMOVIE_TITLE="$DVDMOVIERC_TITLE"
test "$DVDMOVIE_DISCID" != '0' && test -n "$DVDMOVIERC_OPTS" &&
	echo "Adding options $DVDMOVIERC_OPTS from ${RC}." &&
	MOPTS="$MOPTS $DVDMOVIERC_OPTS"
test -n "$*" &&
	echo "Adding options $* from command line." &&
	MOPTS="$MOPTS $*"
printf -- 'Playing DVD title %s with options %s [%s].\n' \
	"$DVDMOVIE_TITLE" "$MOPTS" "$MOPTS ${DISC}${DVDMOVIE_TITLE}"
exec "$MPLAYER" $MOPTS "${DISC}${DVDMOVIE_TITLE}" 2> /dev/null