#!/bin/sh

# Write files/directories on CD or DVD

# Load configuration informations about device
. /etc/sysconfig/cdrecord

# Maximum size in Mbytes
CD_MEDIA_SIZE=700
DVD_MEDIA_SIZE=4400

GROWISOFS_OPTS="-dvd-compat"

# Try to read ATIP infos for CD disks to estimate capacity...
MEDIA_ATIP_INFOS=$(cdrecord dev=${MEDIA_DEV} -atip 2>&1)

if echo ${MEDIA_ATIP_INFOS} | grep -q "ATIP info from disk"; then
    MEDIA_SIZE=${CD_MEDIA_SIZE}
    MEDIA_TYPE="CD"
    echo "CD disk detected"
elif echo ${MEDIA_ATIP_INFOS} | grep -q "Found DVD media but"; then
    MEDIA_SIZE=${DVD_MEDIA_SIZE}
    MEDIA_TYPE="DVD"
    echo "DVD disk detected"
elif echo ${MEDIA_ATIP_INFOS} | grep -q "cdrecord: No disk / Wrong disk"; then
    echo "No disk inserted, aborting"
    exit 1
else
    echo "Unable to determine disk capacity, aborting"
    exit 1
fi

echo "Disk capacity is ${MEDIA_SIZE} Mbytes"

BKP_TMP_DIR=${BKP_TMP_DIR:-"/tmp"}
TMP_FILE="${BKP_TMP_DIR}/media-write-file$$"
TMP_MOUNT="${BKP_TMP_DIR}/media-write-mount$$"

print_usage()
{
    echo "Usage: $(basename $0) files..."
}

evaluate_retval()
{
    last_error=$?
    if [ ${last_error} -ne 0 ]; then
	exit ${last_error}
    fi
}

if [ $# = 0 ]; then
    print_usage
    exit 1
fi

FILES_SIZE="0"

FILES_WRITE_LIST=${*}

for file in ${FILES_WRITE_LIST}; do
    if [ -d ${file} -o -f ${file} ]; then
        FILES_SIZE=$(expr ${FILES_SIZE} + `du -m ${file} -s | sed 's/\([0-9]*\).*/\1/g'`)
    else
	echo "$0: Directory or file ${file} not found."
	print_usage
	exit 1
    fi
done

echo "Total size of files to backup is ${FILES_SIZE}Mbytes"

# The ext2 filesystem is not as space-efficient as the reiser filesystem,
# so we must add a few megabytes...
FILES_SIZE=`expr $FILES_SIZE + 20`

if [ ${FILES_SIZE} -gt ${MEDIA_SIZE} ]; then
    echo "Total size is greater than media capacity, aborting"
    exit 1
    #####FILES_SIZE=${MEDIA_SIZE}
fi

# Create an empty file of $FILES_SIZE
dd if=/dev/zero of=${TMP_FILE} bs=1024k count=${FILES_SIZE}
if [ $? -ne 0 ]; then
    echo "Error while creating empty file..."
    rm -f ${TMP_FILE}
    exit 1
fi

# Create an extended-2 filesystem on this file
echo y | /sbin/mke2fs -m 0 -b 2048 ${TMP_FILE}
if [ $? -ne 0 ]; then
    echo "Error creating file system on empty file..."
    rm -f ${TMP_FILE}
    exit 1
fi

# Mount this empty file through the loopback device.
mkdir -p ${TMP_MOUNT}
mount -o loop -t ext2 ${TMP_FILE} ${TMP_MOUNT}
if [ $? -ne 0 ]; then
    echo "Error mounting empty file..."
    rm -f ${TMP_FILE}
    rm -rf $TMP_MOUNT
    exit 1
fi

# Removing lost+found directory
rmdir ${TMP_MOUNT}/lost+found

# Copy files to $TMP_MOUNT and umount it afterwards.
echo "Copying files..."
cp -a --parents ${FILES_WRITE_LIST} ${TMP_MOUNT}
if [ $? -ne 0 ]; then
    echo "Error while copying files..."
    umount ${TMP_MOUNT}
    rm -rf ${TMP_MOUNT}
    rm -f ${TMP_FILE}
    exit 1
fi

umount ${TMP_MOUNT}

echo Press any key to burn files
read

#***************************************************
# Burning...
#***************************************************
case "${MEDIA_TYPE}" in
    CD)
        cdrecord ${CDRECORD_OPTS} dev=${MEDIA_DEV} -data ${TMP_FILE} || exit 1
	;;
    DVD)
        growisofs ${GROWISOFS_OPTS} -Z /dev/dvd=${TMP_FILE} || exit 1
	;;
    *)
	echo "Unknown removable media type, aborting"
	exit 1
	;;
esac

# Mounting the media to verify burned capacity
if ! grep -q ${MEDIA_DEV} /etc/mtab; then
    mount ${MEDIA_DEV} ${MEDIA_DIR} || exit 1
fi

FILES_SIZE=$(du -m ${MEDIA_DIR} -s | sed 's/\([0-9]*\).*/\1/g')
echo "Total size of files backed-up is ${FILES_SIZE}Mbytes"

umount ${MEDIA_DIR}

rmdir ${TMP_MOUNT}
rm -f ${TMP_FILE}

exit $?