#!/bin/bash

PROGNAME=`basename $0` || exit 1
DEBUG=0
QUIET=0
TARGET=
OVERWRITE=0
WORKDIR=$PWD
OUTPUT=image.iso
CONFIGFILE=$WORKDIR/tortmpcd.conf

function debug {
        if [ "$DEBUG" = "1" ]; then echo "${PROGNAME}:debug:$1" 1>&2; fi
}

function warning {
        if [ "$QUIET" = "0" ]; then echo "${PROGNAME}:warning:$1" 1>&2; fi
}

function usage {
        echo "Usage: ${PROGNAME}" 
        exit
}

while [ "$1" != "" ]; do
        case $1 in
                -D | --debug )
                        shift
                        DEBUG=1
                        ;;
                -q | --quiet )
                        shift
                        QUIET=1
                        ;;
		--overwrite )
			shift
			OVERWRITE=1
			;;
                -h | --help )
                        usage
                        ;;
		-c | --config )
			shift
			CONFIGFILE=$1
			shift
			;;
		-o | --output )
			shift
			OUTPUT=$1
			shift
			;;
                * )
                        echo "$PROGNAME: unrecognized option or argument \`$1'"
                        echo "Try \`$PROGNAME --help' for more information."
                        exit 1
                        ;;
        esac
done

function cleanup {
        debug "cleanup called, arg=$1"
        trap - EXIT HUP INT TERM ERR
	if [ "$TARGET" != "" ]; then
		rm -f -r $TARGET
	fi
        exit $1
}

function fatal {
        echo "${PROGNAME}:${1:-"unknown error"}" 1>&2
        cleanup 1
}

function sig_handler_HUPINTTERM {
        fatal "cought HUP, INT or TERM signal, exiting"
}

function sig_handler_ERR {
	debug "an error occured in a called command"
        cleanup 1
}

function sig_handler_EXIT {
	debug "exit handler called"
        cleanup 0
}


trap sig_handler_HUPINTTERM HUP INT TERM
trap sig_handler_ERR ERR 
trap sig_handler_EXIT EXIT

function get_file {
	debug "looking for package $1"
	RES=$MIRROR/`$PKGDETAILS PKGS $MIRROR $MIRROR/dists/$DIST/main/binary-i386/Packages $1 | cut -f 5 -d ' '`
	if [ "x$RES" = "x$MIRROR/" ]; then
		RES=$MIRROR/`$PKGDETAILS PKGS $MIRROR $MIRROR/dists/$DIST/main/debian-installer/binary-i386/Packages $1 | cut -f 5 -d ' '`
	fi
	if [ "x$RES" = "x$MIRROR/" ]; then
		fatal "unable to find package $1 in either main or main/debian-installer"
	fi
	echo $RES
}

function extract_to_initramfs {
	NAME=$1
	shift
	ar p `get_file $NAME` data.tar.gz | tar --exclude ./usr/share/doc --exclude ./usr/share/lintian --exclude ./usr/share/man --wildcards -xvz -C $TARGET_INITRAMFS "$@"
}

#read configuration

. $CONFIGFILE

debug "using Debian mirror at $MIRROR to get $DIST"

if [ ! -d $MIRROR ]; then
	fatal "$MIRROR does not exist"
fi

if [ ! -d $MIRROR/dists ]; then
	fatal "directory dists/ not found in $MIRROR"
fi

if [ ! -d $MIRROR/dists/$DIST ]; then
	fatal "dist $DIST not found on $MIRROR";
fi

if [ ! -d `dirname $OUTPUT` ]; then
	fatal "output directory \``dirname $OUTPUT`\` does not exist"
fi

if [ -f $OUTPUT -a "$OVERWRITE" = "0" ]; then
	fatal "output file \`$OUTPUT\` already exists"
fi

DESCRIPTION=`cat $MIRROR/dists/$DIST/Release | grep -e "^Description: " | cut -f 2- -d ' '`
debug "using $DESCRIPTION"

TARGET=`mktemp -d`
debug "created temporary directory $TARGET"

mkdir $TARGET/iso9660
TARGET_ISO9660=$TARGET/iso9660

mkdir $TARGET/initramfs
TARGET_INITRAMFS=$TARGET/initramfs

# install pkgdetails binary and point to it
ar p $MIRROR/pool/main/b/base-installer/bootstrap-base_${BBASE_VERSION}_i386.udeb data.tar.gz |
	tar -xz -C $TARGET_INITRAMFS ./usr/lib/debootstrap/pkgdetails
PKGDETAILS=$TARGET_INITRAMFS/usr/lib/debootstrap/pkgdetails
if [ ! -x $PKGDETAILS ]; then
	fatal "$PKGDETAILS not executable?"
fi

KERNELPACKAGE=`get_file linux-image-$DEBIAN_KERNEL`

ar p $KERNELPACKAGE data.tar.gz | tar -xz -C $TARGET_ISO9660 ./boot/vmlinuz-$DEBIAN_KERNEL
mv $TARGET_ISO9660/boot/vmlinuz-$DEBIAN_KERNEL $TARGET_ISO9660/boot/bzImage

mkdir -p $TARGET_ISO9660/isolinux
cp $ISOLINUX $TARGET_ISO9660/isolinux/
cat > $TARGET_ISO9660/isolinux/isolinux.cfg << "X"
PROMPT 1
SAY Booting this will destroy (not in the forensic sense...) the contents of a partition, type "destroy" to boot
LABEL destroy
KERNEL /boot/bzImage
INITRD /boot/initrd.img
X

extract_to_initramfs libc6 ./lib/{libc.so.6,libc-\*.so,libm.so.6,libm-\*.so,ld-linux.so.2,ld-\*.so,libdl.so.2,libdl-\*.so,libpthread.so.0,libpthread-\*.so} 
extract_to_initramfs busybox
extract_to_initramfs libklibc
extract_to_initramfs klibc-utils ./usr/lib/klibc/bin/{sh.shared,run-init,insmod}
extract_to_initramfs binutils ./usr/bin/ar ./usr/lib/libbfd-\*.so
extract_to_initramfs e2fslibs
extract_to_initramfs libblkid1
extract_to_initramfs libuuid1
extract_to_initramfs libpopt0
extract_to_initramfs libcomerr2
extract_to_initramfs e2fsprogs ./sbin/{mkfs.ext2,mke2fs}
extract_to_initramfs debootstrap-udeb

cat > $TARGET_INITRAMFS/init << "X"
#!/usr/lib/klibc/bin/sh.shared
export PATH=/sbin:/bin:/usr/sbin:/usr/bin:/usr/lib/klibc/bin
busybox --install -s
mkdir /proc /sys
mount -t proc none /proc
mount -t sysfs none /sys
mknod /dev/hda b 3 0
mknod /dev/hdb b 3 64
mknod /dev/random c 1 8
mknod /dev/urandom c 1 9
mkdir /mirror
sh.shared -i
X

chmod a+x $TARGET_INITRAMFS/init

cd $TARGET_INITRAMFS
find . | cpio -o -H newc | gzip > $TARGET_ISO9660/boot/initrd.img
cd $WORKDIR

genisoimage -b isolinux/isolinux.bin  -no-emul-boot -boot-load-size 4 -boot-info-table -c isolinux/boot.cat -quiet -r -o $OUTPUT $TARGET_ISO9660