#!/bin/bash

# If a command fails, make the whole script exit
set -e
# Use return code for any command errors in part of a pipe
set -o pipefail # Bashism

# Kali's default values
KALI_DIST="kali-rolling"
KALI_VERSION=""
KALI_VARIANT="default"
IMAGE_TYPE="live"
TARGET_DIR="$(dirname $0)/images"
TARGET_SUBDIR=""
SUDO="sudo"
VERBOSE=""
DEBUG=""
HOST_ARCH=$(dpkg --print-architecture)

image_name() {
	case "$IMAGE_TYPE" in
		live)
			live_image_name
		;;
		installer)
			installer_image_name
		;;
	esac
}

live_image_name() {
	case "$KALI_ARCH" in
		i386|amd64|arm64)
			echo "live-image-$KALI_ARCH.hybrid.iso"
		;;
		armel|armhf)
			echo "live-image-$KALI_ARCH.img"
		;;
	esac
}

installer_image_name() {
	if [ "$KALI_VARIANT" = "netinst" ]; then
		echo "simple-cdd/images/kali-$KALI_VERSION-$KALI_ARCH-NETINST-1.iso"
	else
		echo "simple-cdd/images/kali-$KALI_VERSION-$KALI_ARCH-BD-1.iso"
	fi
}

target_image_name() {
	local arch=$1

	IMAGE_NAME="$(image_name $arch)"
	IMAGE_EXT="${IMAGE_NAME##*.}"
	if [ "$IMAGE_EXT" = "$IMAGE_NAME" ]; then
		IMAGE_EXT="img"
	fi
	if [ "$IMAGE_TYPE" = "live" ]; then
		if [ "$KALI_VARIANT" = "default" ]; then
			echo "${TARGET_SUBDIR:+$TARGET_SUBDIR/}kali-linux-$KALI_VERSION-live-$KALI_ARCH.$IMAGE_EXT"
		else
			echo "${TARGET_SUBDIR:+$TARGET_SUBDIR/}kali-linux-$KALI_VERSION-live-$KALI_VARIANT-$KALI_ARCH.$IMAGE_EXT"
		fi
	else
		if [ "$KALI_VARIANT" = "default" ]; then
			echo "${TARGET_SUBDIR:+$TARGET_SUBDIR/}kali-linux-$KALI_VERSION-installer-$KALI_ARCH.$IMAGE_EXT"
		else
			echo "${TARGET_SUBDIR:+$TARGET_SUBDIR/}kali-linux-$KALI_VERSION-installer-$KALI_VARIANT-$KALI_ARCH.$IMAGE_EXT"
		fi
	fi
}

target_build_log() {
	TARGET_IMAGE_NAME=$(target_image_name $1)
	echo ${TARGET_IMAGE_NAME%.*}.log
}

default_version() {
	case "$1" in
		kali-*)
			echo "${1#kali-}"
		;;
		*)
			echo "$1"
		;;
	esac
}

failure() {
	echo "Build of $KALI_DIST/$KALI_VARIANT/$KALI_ARCH $IMAGE_TYPE image failed (see build.log for details)" >&2
	echo "Log: $BUILD_LOG" >&2
	exit 2
}

run_and_log() {
	if [ -n "$VERBOSE" ] || [ -n "$DEBUG" ]; then
		echo "RUNNING: $@" >&2
		"$@" 2>&1 | tee -a "$BUILD_LOG"
	else
		"$@" >>"$BUILD_LOG" 2>&1
	fi
	return $?
}

debug() {
	if [ -n "$DEBUG" ]; then
		echo "DEBUG: $*" >&2
	fi
}

clean() {
	debug "Cleaning"

	# Live
	run_and_log $SUDO lb clean --purge
	#run_and_log $SUDO umount -l $(pwd)/chroot/proc
	#run_and_log $SUDO umount -l $(pwd)/chroot/dev/pts
	#run_and_log $SUDO umount -l $(pwd)/chroot/sys
	#run_and_log $SUDO rm -rf $(pwd)/chroot
	#run_and_log $SUDO rm -rf $(pwd)/binary

	# Installer
	run_and_log $SUDO rm -rf "$(pwd)/simple-cdd/tmp"
	run_and_log $SUDO rm -rf "$(pwd)/simple-cdd/debian-cd"
}

print_help() {
	echo "Usage: $0 [<option>...]"
	echo
	for x in $(echo "${BUILD_OPTS_LONG}" | sed 's_,_ _g'); do
		x=$(echo $x | sed 's/:$/ <arg>/')
		echo "  --${x}"
	done
	echo
	echo "More information: https://www.kali.org/docs/development/live-build-a-custom-kali-iso/"
	exit 0
}

# Allowed command line options
. $(dirname $0)/.getopt.sh

BUILD_LOG="$(pwd)/build.log"
debug "BUILD_LOG: $BUILD_LOG"
# Create empty file
: > "$BUILD_LOG"

# Parsing command line options (see .getopt.sh)
temp=$(getopt -o "$BUILD_OPTS_SHORT" -l "$BUILD_OPTS_LONG,get-image-path" -- "$@")
eval set -- "$temp"
while true; do
	case "$1" in
		-d|--distribution) KALI_DIST="$2"; shift 2; ;;
		-p|--proposed-updates) OPT_pu="1"; shift 1; ;;
		-a|--arch) KALI_ARCH="$2"; shift 2; ;;
		-v|--verbose) VERBOSE="1"; shift 1; ;;
		-D|--debug) DEBUG="1"; shift 1; ;;
		-s|--salt) shift; ;;
		-h|--help) print_help; ;;
		--installer) IMAGE_TYPE="installer"; shift 1 ;;
		--live) IMAGE_TYPE="live"; shift 1 ;;
		--variant) KALI_VARIANT="$2"; shift 2; ;;
		--version) KALI_VERSION="$2"; shift 2; ;;
		--subdir) TARGET_SUBDIR="$2"; shift 2; ;;
		--get-image-path) ACTION="get-image-path"; shift 1; ;;
		--clean) ACTION="clean"; shift 1; ;;
		--no-clean) NO_CLEAN="1"; shift 1 ;;
		--) shift; break; ;;
		*) echo "ERROR: Invalid command-line option: $1" >&2; exit 1; ;;
	esac
done

# Set default values
KALI_ARCH=${KALI_ARCH:-$HOST_ARCH}
if [ "$KALI_ARCH" = "x64" ]; then
	KALI_ARCH="amd64"
elif [ "$KALI_ARCH" = "x86" ]; then
	KALI_ARCH="i386"
fi
debug "KALI_ARCH: $KALI_ARCH"

if [ -z "$KALI_VERSION" ]; then
	KALI_VERSION="$(default_version $KALI_DIST)"
fi
debug "KALI_VERSION: $KALI_VERSION"

# Check parameters
debug "HOST_ARCH: $HOST_ARCH"
if [ "$HOST_ARCH" != "$KALI_ARCH" ] && [ "$IMAGE_TYPE" != "installer" ]; then
	case "$HOST_ARCH/$KALI_ARCH" in
		amd64/i386|i386/amd64)
		;;
		*)
			echo "Can't build $KALI_ARCH image on $HOST_ARCH system." >&2
			exit 1
		;;
	esac
fi

# Build parameters for lb config
KALI_CONFIG_OPTS="--distribution $KALI_DIST -- --variant $KALI_VARIANT"
CODENAME=$KALI_DIST # for simple-cdd/debian-cd
if [ -n "$OPT_pu" ]; then
	KALI_CONFIG_OPTS="$KALI_CONFIG_OPTS --proposed-updates"
	KALI_DIST="$KALI_DIST+pu"
fi
debug "KALI_CONFIG_OPTS: $KALI_CONFIG_OPTS"
debug "CODENAME: $CODENAME"
debug "KALI_DIST: $KALI_DIST"

# Set sane PATH (cron seems to lack /sbin/ dirs)
export PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
debug "PATH: $PATH"

if grep -q -e "^ID=debian" -e "^ID_LIKE=debian" /usr/lib/os-release; then
	debug "OS: $( . /usr/lib/os-release && echo $NAME $VERSION )"
elif [ -e /etc/debian_version ]; then
	debug "OS: $( cat /etc/debian_version )"
else
	echo "ERROR: Non Debian-based OS" >&2
fi

debug "IMAGE_TYPE: $IMAGE_TYPE"
case "$IMAGE_TYPE" in
	live)
		if [ ! -d "$(dirname $0)/kali-config/variant-$KALI_VARIANT" ]; then
			echo "ERROR: Unknown variant of Kali live configuration: $KALI_VARIANT" >&2
		fi

		ver_live_build=$(dpkg-query -f '${Version}' -W live-build)
		if dpkg --compare-versions "$ver_live_build" lt "1:20230131+kali5"; then
			echo "ERROR: You need live-build (>= 1:20230131+kali5), you have $ver_live_build" >&2
			exit 1
		fi
		debug "ver_live_build: $ver_live_build"

		ver_debootstrap=$(dpkg-query -f '${Version}' -W debootstrap)
		if dpkg --compare-versions "$ver_debootstrap" lt "1.0.97"; then
			echo "ERROR: You need debootstrap (>= 1.0.97), you have $ver_debootstrap" >&2
			exit 1
		fi
		debug "ver_debootstrap: $ver_debootstrap"
	;;
	installer)
		if [ ! -d "$(dirname $0)/kali-config/installer-$KALI_VARIANT" ]; then
			echo "ERROR: Unknown variant of Kali installer configuration: $KALI_VARIANT" >&2
		fi

		ver_debian_cd=$(dpkg-query -f '${Version}' -W debian-cd)
		if dpkg --compare-versions "$ver_debian_cd" lt 3.2.1+kali1; then
			echo "ERROR: You need debian-cd (>= 3.2.1+kali1), you have $ver_debian_cd" >&2
			exit 1
		fi
		debug "ver_debian_cd: $ver_debian_cd"

		ver_simple_cdd=$(dpkg-query -f '${Version}' -W simple-cdd)
		if dpkg --compare-versions "$ver_simple_cdd" lt 0.6.9; then
			echo "ERROR: You need simple-cdd (>= 0.6.9), you have $ver_simple_cdd" >&2
			exit 1
		fi
		debug "ver_simple_cdd: $ver_simple_cdd"
	;;
	*)
		echo "ERROR: Unsupported IMAGE_TYPE selected ($IMAGE_TYPE)" >&2
		exit 1
	;;
esac

# We need root rights at some point
if [ "$(whoami)" != "root" ]; then
	if ! which $SUDO >/dev/null; then
		echo "ERROR: $0 is not run as root and $SUDO is not available" >&2
		exit 1
	fi
else
	SUDO="" # We're already root
fi
debug "SUDO: $SUDO"

IMAGE_NAME="$(image_name $KALI_ARCH)"
debug "IMAGE_NAME: $IMAGE_NAME"

debug "ACTION: $ACTION"
if [ "$ACTION" = "get-image-path" ]; then
	echo $(target_image_name $KALI_ARCH)
	exit 0
fi

if [ "$NO_CLEAN" = "" ]; then
	clean
fi
if [ "$ACTION" = "clean" ]; then
	exit 0
fi

cd $(dirname $0)
mkdir -p $TARGET_DIR/$TARGET_SUBDIR

# Don't quit on any errors now
set +e

case "$IMAGE_TYPE" in
	live)
		debug "Stage 1/2 - Config"
		run_and_log lb config -a $KALI_ARCH $KALI_CONFIG_OPTS "$@"
		[ $? -eq 0 ] || failure

		debug "Stage 2/2 - Build"
		run_and_log $SUDO lb build
		if [ $? -ne 0 ] || [ ! -e $IMAGE_NAME ]; then
			failure
		fi
	;;
	installer)
		# Override some debian-cd environment variables
		export BASEDIR="$(pwd)/simple-cdd/debian-cd"
		export ARCHES=$KALI_ARCH
		export ARCH=$KALI_ARCH
		export DEBVERSION=$KALI_VERSION
		debug "BASEDIR: $BASEDIR"
		debug "ARCHES: $ARCHES"
		debug "ARCH: $ARCH"
		debug "DEBVERSION: $DEBVERSION"

		if [ "$KALI_VARIANT" = "netinst" ]; then
			export DISKTYPE="NETINST"
			profiles="kali"
			auto_profiles="kali"
		elif [ "$KALI_VARIANT" = "purple" ]; then
			export DISKTYPE="BD"
			profiles="kali kali-purple offline"
			auto_profiles="kali kali-purple offline"
			export KERNEL_PARAMS="debian-installer/theme=Clearlooks-Purple"
		else    # plain installer
			export DISKTYPE="BD"
			profiles="kali offline"
			auto_profiles="kali offline"
		fi
		debug "DISKTYPE: $DISKTYPE"
		debug "profiles: $profiles"
		debug "auto_profiles: $auto_profiles"
		[ -v KERNEL_PARAMS ] && debug "KERNEL_PARAMS: $KERNEL_PARAMS"

		if [ -e .mirror ]; then
			kali_mirror=$(cat .mirror)
		else
			kali_mirror=http://archive.kali.org/kali/
		fi
		if ! echo "$kali_mirror" | grep -q '/$'; then
			kali_mirror="$kali_mirror/"
		fi
		debug "kali_mirror: $kali_mirror"

		debug "Stage 1/2 - File(s)"
		# Setup custom debian-cd to make our changes
		cp -aT /usr/share/debian-cd simple-cdd/debian-cd
		[ $? -eq 0 ] || failure

		# Use the same grub theme as in the live images
		# Until debian-cd is smart enough: http://bugs.debian.org/1003927
		cp -f kali-config/common/bootloaders/grub-pc/grub-theme.in simple-cdd/debian-cd/data/$CODENAME/grub-theme.in

		# Keep 686-pae udebs as we changed the default from 686
		# to 686-pae in the debian-installer images
		sed -i -e '/686-pae/d' \
			simple-cdd/debian-cd/data/$CODENAME/exclude-udebs-i386
		[ $? -eq 0 ] || failure

		# Configure the kali profile with the packages we want
		grep -v '^#' kali-config/installer-$KALI_VARIANT/packages \
			> simple-cdd/profiles/kali.downloads
		[ $? -eq 0 ] || failure

		# Tasksel is required in the mirror for debian-cd
		echo tasksel >> simple-cdd/profiles/kali.downloads
		[ $? -eq 0 ] || failure

		# Grub is the only supported bootloader on arm64
		# so ensure it's on the iso for arm64.
		if [ "$KALI_ARCH" = "arm64" ]; then
			debug "arm64 GRUB"
			echo "grub-efi-arm64" >> simple-cdd/profiles/kali.downloads
			[ $? -eq 0 ] || failure
		fi

		# Run simple-cdd
		debug "Stage 2/2 - Build"
		cd simple-cdd/
		run_and_log build-simple-cdd \
			--verbose \
			--debug \
			--force-root \
			--conf simple-cdd.conf \
			--dist $CODENAME \
			--debian-mirror $kali_mirror \
			--profiles "$profiles" \
			--auto-profiles "$auto_profiles"
		res=$?
		cd ../
		if [ $res -ne 0 ] || [ ! -e $IMAGE_NAME ]; then
			failure
		fi
	;;
esac

# If a command fails, make the whole script exit
set -e

debug "Moving files"
run_and_log mv -f $IMAGE_NAME $TARGET_DIR/$(target_image_name $KALI_ARCH)
run_and_log mv -f "$BUILD_LOG" $TARGET_DIR/$(target_build_log $KALI_ARCH)

run_and_log echo -e "\n***\nGENERATED KALI IMAGE: $TARGET_DIR/$(target_image_name $KALI_ARCH)\n***"