#!@SH@

set -u

# This should be maintained in order of compatibility, i.e. each arch can also
# run programs built for the arches before it.
ARCHES='i686 amd64'

# Description		CPU	Plat
PLATS='
Acer Aspire One AO751h	i686	ao751h
Dell Dimension 2400	i686	dimension2400
Lenovo ThinkPad X60/X60s/X60t	i686	x60
'

main()
{
	local opt=
	local mirror=
	local install_arch=
	local host_arch=
	local host_plat=
	local mountpoint=
	local b4=
	local b3=
	local b2=
	local b1=

	while getopts 'm:' opt; do
		case ${opt} in
			m) mirror="${OPTARG}";;
			?)
				print_usage >&2
				exit 1
				;;
		esac
	done
	shift $(($OPTIND - 1))
	if [ ${#} -ne 0 ]; then
		print_usage >&2
		exit 1
	fi

	install_arch="$(detect_arch)"
	printf '\nSelect a platorm'
	printf '\n================\n\n'
	read host_arch host_plat <<-EOF
		$(prompt_plat)
		EOF
	host_arch="${host_arch}-${install_arch#*-}"
	check_arch_compat "${install_arch}" "${host_arch}"

	printf '\nSelect a block device'
	printf '\n=====================\n\n'
	dev="$(prompt_block_dev)"

	printf '\nMaking partition table and file system'
	printf '\n======================================\n\n'
	make_partition_and_fs "${dev}"

	printf '\nInstalling base system'
	printf '\n======================\n\n'

	mountpoint="$(mount_fs "${dev}")"

	"${0%installers/pc}src/prokit" install \
		-a "${host_arch}" -p "${host_plat}" \
		${mirror:+-m} ${mirror} 'dev/trunk' "${mountpoint}"

	printf '\nInstalling boot loader'
	printf '\n======================\n\n'

	read b4 b3 b2 b1 <<-EOF
		$(od -An -tx1 -v -j 440 -N 4 "/dev/${dev}")
		EOF
	# This ln command won't be needed once lilo 24.1-1 is uploaded.
	ln "${mountpoint}/boot/vmlinuz" "${mountpoint}/boot/vmlinuz.old"
	"${0%installers/pc}src/prokit" shell "${mountpoint}" \
		install-lilo "/dev/${dev}" "PARTUUID=${b1}${b2}${b3}${b4}-01"

	umount_fs "${mountpoint}"
}

print_usage()
{
	printf 'Usage: %s [-m <mirror>]\n' "${0}"
}

error()
{
	local status=${1}
	local fmt="${2}"
	shift 2

	printf "Error: ${fmt}\n" "${@}" >&2

	exit ${status}
}

_select()
{
	# Field width of the prompt numbers.
	select_width=$(expr ${#} : '.*')

	select_i=

	while :; do
		case "${select_i}" in
			'')
				select_i=0
				for select_word in "${@}"; do
					select_i=$(expr ${select_i} + 1)
					printf "%${select_width}d) %s\\n" \
						${select_i} "${select_word}" \
						>&2
				done
				;;
			*[!0-9]*)
				printf 'Please enter a number in range.\n' >&2
				;;
			*)
				if [ ${select_i} -gt 0 ] && \
						[ ${select_i} -le ${#} ]; then
					shift $(expr $select_i - 1)
					select_result="${1}"
					break
				fi
				printf 'Please enter a number in range.\n' >&2
				;;
		esac

		# Prompt and read input.
		printf '%s' "${PS3-#? }" >&2
		read -r select_i || exit
	done
}

detect_arch()
{
	local uname_m=
	local uname_s=
	local arch=

	uname_m="$( (uname -m) 2>/dev/null)" || uname_m='?'
	uname_s="$( (uname -s) 2>/dev/null)" || uname_s='?'
	case "${uname_m}:${uname_s}" in
		'i686:Linux') arch='i686-linux-glibc';;
		'x86_64:Linux') arch='amd64-linux-glibc';;
		'?:?') error 2 'Architecture unknown';;
		*) error 2 'Architecture unsupported';;
	esac

	printf '%s\n' "${arch}"
}

prompt_plat()
{
	local desc=
	local arch=
	local plat=

	set --
	while IFS='	' read -r desc arch plat; do
		[ "x${desc}" = 'x' ] && continue
		set -- "${@}" "${desc}"
	done <<-EOF
		${PLATS}
		EOF

	printf 'Select a platform:\n' >&2
	_select "${@}"

	while IFS='	' read -r desc arch plat; do
		if [ "x${desc}" = "x${select_result}" ]; then
			printf '%s %s\n' "${arch}" "${plat}"
			break
		fi
	done <<-EOF
		${PLATS}
		EOF
}

check_arch_compat()
{
	local install_arch="${1}"
	local host_arch="${2}"
	local arches=
	local install_cpu=
	local host_cpu=

	if [ "x${install_arch}" = "x${host_arch}" ]; then
		return 0
	fi

	arches="$(printf ' %s ' ${ARCHES})"
	install_cpu="${install_arch%%-*}"
	host_cpu="${host_arch%%-*}"
	if [ "x${arches#* ${host_cpu} * ${install_cpu} }" = "x${arches}" ]
	then
		error 2 'Cannot install a system of architecture %s on %s %s' \
			"${host_arch}" 'a system of architecture' \
			"${install_arch}"
	fi
}

pretty_print_size_dec()
{
	local size="${1}"

	awk -v size=${size} 'BEGIN {
		split("B KB MB GB TB", units, " ");
		i=1;
		while (size >= 1000) {
			size /= 1000;
			++i;
		};
		printf("%.2f %s\n", size, units[i]); }'
}

pretty_print_size_bin()
{
	local size="${1}"

	awk -v size=${size} 'BEGIN {
		split("B KiB MiB GiB TiB", units, " ");
		i=1;
		while (size >= 1024) {
			size /= 1024;
			++i;
		};
		printf("%.2f %s\n", size, units[i]); }'
}

prompt_block_dev()
{
	local dev=
	local vendor=
	local model=
	local name=
	local size=
	local size_s=
	local desc=
	local devs=

	set --
	for dev in /sys/block/*; do
		dev="${dev#/sys/block/}"
		case "${dev}" in
			loop*|sr*) continue;;
		esac
		if [ -e "/sys/block/${dev}/device/vendor" ]; then
			vendor="$(cat "/sys/block/${dev}/device/vendor")"
			model="$(cat "/sys/block/${dev}/device/model")"
			name="${vendor} ${model}"
		else
			name="$(cat "/sys/block/${dev}/device/name")"
		fi
		size="$(cat "/sys/block/${dev}/size")"
		size="$(expr ${size} \* 512)"
		size_s="$(pretty_print_size_dec "${size}")"
		size_s="${size_s} ($(pretty_print_size_bin "${size}"))"
		desc="$(printf '%s (%s) - %s\n' "${name}" "${dev}" "${size_s}")"
		set -- "${@}" "${desc}"
		devs="$(printf '%s\n%s\t%s\n' "${devs}" "${desc}" "${dev}")"
	done

	printf 'Select a block device:\n' >&2
	_select "${@}"

	while IFS='	' read -r desc dev; do
		if [ "x${desc}" = "x${select_result}" ]; then
			printf '%s\n' "${dev}"
		fi
	done <<-EOF
		${devs}
		EOF
}

make_partition_and_fs()
{
	local dev="${1}"

	dd if=/dev/zero of="/dev/${dev}" bs=512 count=1
	printf 'n\np\n1\n\n\nt\n83\na\n1\nw\n' | fdisk "/dev/${dev}"
	mke2fs -t ext4 "/dev/${dev}1"
}

mount_fs()
{
	local dev="${1}"
	local mountpoint=

	mountpoint="$(mktemp -d)"
	mount "/dev/${dev}1" "${mountpoint}"
	printf '%s\n' "${mountpoint}"
}

umount_fs()
{
	local mountpoint="${1}"

	while ! umount "${mountpoint}"; do
		sleep 1
	done
	rmdir "${mountpoint}"
}

main "${@}"