#
# burn_audio -- A script for converting MP3s to WAVs for burning with cdrdao.
#

# REQUIRES: cdrdao (for burning); lame (for decoding MP3s)

# NOTE: Make sure /etc/cdrdao.conf contains a line specifying the device, e.g.:
#	write_device: "/dev/cdrw0"

# This is a modified version of the loops posted on the Arch Linux Wiki at:
# http://wiki.archlinux.org/index.php/Creating_gapless_audio_CDs_from_MP3_HOWTO

#
# USAGE:
# ./burn_audio [-gap | -nogap] FILES_PATH TEMP_PATH
# ARGUMENTS:
# 	-gap		Add a 2-second silence before each track.
#	-nogap		No silence will be added before tracks (i.e. gapless).
#

if [ -z $3 ] ; then
	echo "ERROR: Not enough arguments."
	echo "You need to specify the following:"
	echo "  - either -gap or -nogap,"
	echo "  - the path to the directory with the MP3s you want to burn, and"
	echo "  - the path to a working directory (which will be created by this script)."
	echo
	echo "e.g.:  ./burn_audio -nogap ~/music /tmp/to_burn"
	exit 1
fi

if [ ! -z $4 ] ; then
	echo "ERROR: Too many arguments."
	echo "You provided more than 3 arguments (the 4th argument you entered was: $4)."
	exit 1
fi

if [ $1 == "-gap" ] ; then
	echo "A 2-second silence will be added before each track."
	BURN_WITH_GAP = "true"
else 
	if [ $1 == "-nogap" ] ; then
		echo "The tracks will be written gaplessly."
	else
		echo "ERROR: Invalid argument: $1"
		echo "Either -gap or -nogap is required as the first argument."
		exit 1
	fi
fi

if [ ! -d $2 ] ; then
    echo "ERROR: The FILES_PATH does not exist."
    exit 1
fi

FILES_PATH="$2"
TEMP_PATH="$3"

mkdir -p $TEMP_PATH
for file in $FILES_PATH/*.mp3 ; do
   lame --decode "$file" "$TEMP_PATH/$file.wav"
done

cd $TEMP_PATH
{
  echo "CD_DA"
  for file in *.wav ; do
    echo "TRACK AUDIO"
    if [ $BURN_WITH_GAP = "true" ] ; then
    	echo "PREGAP 00:02:00"
    else
    fi
    echo "FILE \"$file\" 0"
  done
} > TOC

echo "Please review the TOC file created before burning."
less TOC

echo "Begin burning to disc? [y/n] "
read
if [ $REPLY == "y" || $REPLY == "Y" ] ; then
	echo "Executing command: cdrdao write TOC"
	cdrdao write TOC
else
	echo "Aborting."
	exit 0
fi