#!/bin/sh
#
# © 2022 Johannes Schauer Marin Rodrigues <josch@mister-muffin.de>
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to
# deal in the Software without restriction, including without limitation the
# rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
# sell copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# The software is provided "as is", without warranty of any kind, express or
# implied, including but not limited to the warranties of merchantability,
# fitness for a particular purpose and noninfringement. In no event shall the
# authors or copyright holders be liable for any claim, damages or other
# liability, whether in an action of contract, tort or otherwise, arising
# from, out of or in connection with the software or the use or other dealings
# in the software.

set -eu

# This script creates debian-$RELEASE.qcow2 in the current directory which can
# then be used by the autopkgtest qemu backend.
#
# Thanks to Francesco Poli for providing ideas and testing this.
#
# Thanks to Lars Wirzenius of vmdb2 where the grub and efi magic comes from.
#
# Only the native architecture is supported because guestfish doesn't support
# foreign architectures.

usage() {
	echo "Usage: $0 [--size=SIZE] [--boot=BOOT] RELEASE IMAGE" >&2
	echo >&2
	echo "RELEASE is a Debian release like unstable" >&2
	echo "IMAGE will be stored in qcow2 format" >&2
	echo "SIZE is 25G by default" >&2
	echo "BOOT is either auto (the default), bios, efi or ieee1275" >&2
}

nativearch="$(dpkg --print-architecture)"

SIZE="25G" # default from autopkgtest-build-qemu
BOOT="auto"
if [ "$#" -lt 2 ]; then
	echo "Error: Insufficient number of arguments" >&2
	usage
	exit 1
elif [ "$#" -eq 2 ]; then
	RELEASE=$1
	IMAGE=$2
else
	# parse options
	OPTS=$(getopt -n "$0" -o h --long size:,boot:,architecture:,help -- "$@")
	if [ "$?" -ne 0 ]; then
		echo "Error: Cannot parse arguments" >&2
		usage
		exit 1
	fi
	eval set -- "$OPTS"
	while true; do
		case "$1" in
			--size) SIZE="$2"; shift 2; continue;;
			--boot) BOOT="$2"; shift 2; continue;;
			--help) usage; exit 1;;
			--architecture)
				echo "Error: cannot (yet) create foreign architecture images" >&2
				exit 1
				;;
			--) shift; break;;
			*)
				echo "Error: unknown option $1" >&2
				usage
				exit 1
				;;
		esac
	done
	RELEASE=$1
	IMAGE=$2
fi

# By default with --boot=auto (the default), bios boot is chosen for
# amd64 and i386. Compare /usr/share/autopkgtest/lib/autopkgtest_qemu.py
# But in practice, amd64 and i386 also support efi boot. But then
# autopkgtest-virt-qemu has to be run with --boot=efi
case "$BOOT" in
	auto)
		case "$nativearch" in
			amd64|i386) BOOT=bios;;
			armhf|arm64) BOOT=efi;;
			ppc64el) BOOT=ieee1275;;
		esac
		;;
	bios)
		case "$nativearch" in amd64|i386);;
			*)
				echo "bios booting only possible on amd64 and i386" >&2
				exit 1
				;;
		esac
		;;
	efi)
		case "$nativearch" in amd64|i386|armhf|arm64);;
			*)
				echo "efi booting only possible on amd64, i386, armhf and arm64" >&2
				exit 1
				;;
		esac
		;;
	ieee1275)
		if [ "$nativearch" != "ppc64el" ]; then
			echo "ieee1275 booting only possible on ppc64el" >&2
			exit 1
		fi
		;;
	*)
		echo "invalid value for --boot" >&2;;
esac

case "$nativearch" in
	amd64)
		[ $BOOT = bios ] || [ $BOOT = efi ]
		if [ $BOOT = bios ]; then
			include="linux-image-amd64 grub-pc"
			grub_target="i386-pc"
		elif [ $BOOT = efi ]; then
			include="linux-image-amd64 grub-efi"
			grub_target="x86_64-efi"
		fi
		;;
	arm64)
		[ $BOOT = efi ]
		include="linux-image-arm64 grub-efi"
		grub_target="arm64-efi"
		;;
	armhf)
		[ $BOOT = efi ]
		include="linux-image-armmp-lpae grub-efi"
		grub_target="arm-efi"
		;;
	i386)
		[ $BOOT = bios ] || [ $BOOT = efi ]
		if [ $BOOT = bios ]; then
			include="linux-image-686-pae grub-pc"
			grub_target="i386-efi"
		elif [ $BOOT = efi ]; then
			include="linux-image-686-pae grub-efi"
			grub_target="i386-efi"
		fi
		;;
	ppc64el)
		[ $BOOT = ieee1275 ]
		include="linux-image-powerpc64le grub-ieee1275"
		grub_target="powerpc-ieee1275"
		;;
	*)
		echo "architecture $nativearch not yet supported" >&2
		exit 1
		;;
esac

case "$nativearch" in
	arm64|armhf) serial="loglevel=3 console=tty0 console=ttyAMA0,115200n8" ;;
	ppc64el) serial="loglevel=3 console=tty0 console=hvc0,115200n8" ;;
	*) serial="loglevel=3 console=tty0 console=ttyS0,115200n8" ;;
esac

if ! command -v guestfish >/dev/null; then
	echo "Error: requires guestfish being installed" >&2
	exit 1
fi

if [ ! -e /usr/share/autopkgtest/setup-commands/setup-testbed ]; then
	echo "Error: requires autopkgtest being installed" >&2
	exit 1
fi

run_mmdebstrap() {
	mmdebstrap --variant=important --include="$include" \
	--customize-hook='chroot "$1" passwd --delete root' \
	--customize-hook='chroot "$1" useradd --home-dir /home/user --create-home user' \
	--customize-hook='chroot "$1" passwd --delete user' \
	--customize-hook='echo host > "$1/etc/hostname"' \
	--customize-hook='echo "127.0.0.1 localhost host" > "$1/etc/hosts"' \
	--customize-hook='env AUTOPKGTEST_BUILD_QEMU=1 /usr/share/autopkgtest/setup-commands/setup-testbed "$1"' \
	"$RELEASE" -
}

guestfish_bios() {
	guestfish -- \
	disk-create "$IMAGE" qcow2 "$SIZE" : \
	add-drive "$IMAGE" format:qcow2 : \
	launch : \
	part-disk /dev/sda mbr : \
	part-set-bootable /dev/sda 1 true : \
	mkfs ext4 /dev/sda1 : mount /dev/sda1 / : \
	tar-in - / xattrs:true : \
	command "sh -c 'echo UUID=\$(blkid -c /dev/null -o value -s UUID /dev/sda1) / ext4 errors=remount-ro 0 1 > /etc/fstab'" : \
	command "update-initramfs -u" : \
	command "grub-mkconfig -o /boot/grub/grub.cfg" : \
	command "grub-install /dev/sda --target=$grub_target --no-nvram --force-extra-removable --no-floppy --modules=part_gpt --grub-mkdevicemap=/boot/grub/device.map" : \
	sync : umount / : shutdown
}

guestfish_efi() {
	guestfish -- \
	disk-create "$IMAGE" qcow2 "$SIZE" : \
	add-drive "$IMAGE" format:qcow2 : \
	launch : \
	part-init /dev/sda gpt : \
	part-add /dev/sda primary 8192 262144 : \
	part-add /dev/sda primary 262145 -34 : \
	part-set-gpt-type /dev/sda 1 C12A7328-F81F-11D2-BA4B-00A0C93EC93B  : \
	mkfs ext4 /dev/sda2 : mount /dev/sda2 / : \
	tar-in - / xattrs:true : \
	mkdir-p /boot/efi : \
	mkfs vfat /dev/sda1 : mount /dev/sda1 /boot/efi : \
	command "sh -c 'echo UUID=\$(blkid -c /dev/null -o value -s UUID /dev/sda2) / ext4 errors=remount-ro 0 1 > /etc/fstab'" : \
	command "sh -c 'echo UUID=\$(blkid -c /dev/null -o value -s UUID /dev/sda1) /boot/efi vfat errors=remount-ro 0 2 >> /etc/fstab'" : \
	command "sed -i 's/^GRUB_CMDLINE_LINUX_DEFAULT=/GRUB_CMDLINE_LINUX_DEFAULT=\"biosdevname=0 net.ifnames=0 consoleblank=0 rw $serial\"/' /etc/default/grub" : \
	command "update-initramfs -u" : \
	command "grub-mkconfig -o /boot/grub/grub.cfg" : \
	command "grub-install /dev/sda --target=$grub_target --no-nvram --force-extra-removable --no-floppy --modules=part_gpt --grub-mkdevicemap=/boot/grub/device.map" : \
	sync : umount /boot/efi : umount / : shutdown
}

guestfish_ieee1275() {
	guestfish -- \
	disk-create "$IMAGE" qcow2 "$SIZE" : \
	add-drive "$IMAGE" format:qcow2 : \
	launch : \
	part-init /dev/sda gpt : \
	part-add /dev/sda primary 8192 20480 : \
	part-add /dev/sda primary 20481 -34 : \
	part-set-gpt-type /dev/sda 1 9E1A2D38-C612-4316-AA26-8B49521E5A8B : \
	mkfs ext4 /dev/sda2 : mount /dev/sda2 / : \
	tar-in - / xattrs:true : \
	command "sh -c 'echo UUID=\$(blkid -c /dev/null -o value -s UUID /dev/sda2) / ext4 errors=remount-ro 0 1 > /etc/fstab'" : \
	command "sed -i 's/^GRUB_CMDLINE_LINUX_DEFAULT=/GRUB_CMDLINE_LINUX_DEFAULT=\"biosdevname=0 net.ifnames=0 consoleblank=0 rw $serial\"/' /etc/default/grub" : \
	command "update-initramfs -u" : \
	command "grub-mkconfig -o /boot/grub/grub.cfg" : \
	command "grub-install /dev/sda --target=$grub_target --no-nvram --force-extra-removable --no-floppy --modules=part_gpt --grub-mkdevicemap=/boot/grub/device.map" : \
	sync : umount / : shutdown
}

case "$BOOT" in
	bios) run_mmdebstrap | guestfish_bios;;
	efi) run_mmdebstrap | guestfish_efi;;
	ieee1275) run_mmdebstrap | guestfish_ieee1275;;
esac

echo "Success! The image is stored as $IMAGE" >&2