#!/bin/sh

set -u

host=
dev=
target=

err()
{
	local fmt="${1}"
	shift 1

	printf "Error: ${fmt}\n" "${@}" 1>&3
}

info()
{
	local fmt="${1}"
	shift 1

	printf "${fmt}\n" "${@}" 1>&3
}

in_target()
{
	chroot "${target}" "${@}" || return 1

	return 0
}

do_()
{
	step="${1}"
	shift 1

	do_${step} 1>&4 2>&4
}

do_fdisk()
{
	local script=
	local line=

	info 'Making partition table'

	script=
	while read line; do
		script="$(printf '%s\n' "${script}" "${line}")"
	done <<-EOF
		${part_script}
		EOF
	printf '%s\n' "${script}" | sfdisk "${dev}"

	return 0
}

do_mkfs()
{
	local fs=
	local mp=
	local type=
	local options=
	local dump=
	local pass=

	info 'Making file systems'

	while read fs mp type options dump pass; do
		case "${type}" in ''|'swap') continue;; esac
		case "${fs}" in
			'@DEV'*'@')
				fs="${fs%@}"
				fs="${fs#@DEV}"
				fs="${dev}${fs}"
				;;
			*)
				continue
				;;
		esac
		mkfs -t "${type}" "${fs}" || return 1
	done <<-EOF
		${fstab}
		EOF

		return 0
}

do_mount()
{
	local fs=
	local mp=
	local type=
	local options=
	local dump=
	local pass=

	info 'Mounting file systems'

	target="$(mktemp -d)"

	while read fs mp type options dump pass; do
		case "${type}" in ''|'swap') continue;; esac
		case "${fs}" in
			'@DEV'*'@')
				fs="${fs%@}"
				fs="${fs#@DEV}"
				fs="${dev}${fs}"
				;;
			*)
				continue
				;;
		esac
		mkdir -p "${target}${mp}" || return 1
		mount -t "${type}" ${options:+-o "${options}"} \
			"${fs}" "${target}${mp}" || return 1
	done <<-EOF
		${fstab}
		EOF

		return 0
}

do_check_target()
{
	if [ -e "${target}/bin/sh" ]; then
		err 'Unclean target'
		return 1
	fi

	return 0
}

do_debootstrap()
{
	local include=

	info 'Installing base system'

	case "${extra_pkgs}" in ?*)
		include="--include=$(printf '%s,' ${extra_pkgs})"
		include="${include%,}"
	;; esac

	debootstrap --arch="${arch}" "${include}" \
		"${suite}" "${target}" "${mirror}" || return 1

	return 0
}

do_chroot_setup()
{
	info 'Setting up system'

	case "$(uname -s)" in
		'Linux')
			mount -t proc proc "${target}/proc" || return 1
			mount -t sysfs sysfs "${target}/sys" || return 1
			mount --bind /dev "${target}/dev" || return 1
			mkdir -p "${target}/dev/pts" || return 1
			mount -t devpts -o noexec,nosuid,gid=5,mode=620 \
				devpts "${target}/dev/pts" || return 1
			mount --bind /run "${target}/run" || return 1
			;;
	esac

	cat >"${target}/usr/sbin/policy-rc.d" <<-EOF
		#!/bin/sh
		exit 101
		EOF
	chmod a+rx "${target}/usr/sbin/policy-rc.d" || return 1

	if [ -e "${target}/sbin/start-stop-daemon" ]; then
		in_target dpkg-divert --quiet --add \
			--divert '/sbin/start-stop-daemon.REAL' \
			--rename '/sbin/start-stop-daemon' || return 1
	fi
	cat >"${target}/sbin/start-stop-daemon" <<-EOF
		#!/bin/sh
		exit 0
		EOF
	chmod a+rx "${target}/sbin/start-stop-daemon" || return 1

	printf '%s\n' "${hostname}" >"${target}/etc/hostname"

	cat >"${target}/etc/hosts" <<-EOF
	127.0.0.1	localhost

	# The following lines are desirable for IPv6 capable hosts
	::1     ip6-localhost ip6-loopback
	fe00::0 ip6-localnet
	ff00::0 ip6-mcastprefix
	ff02::1 ip6-allnodes
	ff02::2 ip6-allrouters
	EOF

	mkdir -p "${target}/etc/network" || return 1
	cat >"${target}/etc/network/interfaces" <<-EOF
	# This file describes the network interfaces available on your system
	# and how to activate them. For more information, see interfaces(5).

	# The loopback network interface
	auto lo
	iface lo inet loopback
	EOF

	for file in /etc/networks /etc/resolv.conf; do
		if ! [ -f "${file}" ]; then
			continue
		fi
		if [ -f "${target}${file}" ]; then
			mv "${target}${file}" "${target}${file}.REAL"
		fi
		mkdir -p "${target}${file%/*}"
		cp "${file}" "${target}${file}"
	done

	export LANG="${locale}"
	export PERL_BADLANG=0
	export DEBCONF_ADMIN_EMAIL=''
	export IT_LANG_OVERRIDE='C'
	export APT_LISTCHANGES_FRONTEND='none'
	export SUDO_FORCE_REMOVE='yes'

	return 0
}

do_fstab_setup()
{
	local fs=
	local mp=
	local type=
	local options=
	local dump=
	local pass=

	info 'Making file system table'

	case "$(uname -s)" in
		'Linux')
			printf '%-15s %-15s %-7s %-15s %-7s %s\n' \
				'proc' '/proc' 'proc' 'defaults' '0' '0' \
				>"${target}/etc/fstab"
			;;
	esac
	while read fs mp type options dump pass; do
		case "${fs}" in '@DEV'*'@')
			fs="${fs%@}"
			fs="${fs#@DEV}"
			fs="${dev}${fs}"
			fs="UUID=$(blkid -o value -s UUID "${fs}")"
		;; esac
		printf '%-15s %-15s %-7s %-15s %-7s %s\n' \
			"${fs}" "${mp}" "${type}" "${options}" \
			"${dump}" "${pass}" >>"${target}/etc/fstab"
	done <<-EOF
		${fstab}
		EOF
}

do_apt_update()
{
	info 'Downloading package lists'

	in_target apt-get update || return 1

	return 0
}

do_locale_setup()
{
	local l=
	local gen=

	info 'Setting locale'

	if ! [ "x${locale}" = 'xC' ] || ! [ "x${supported_locales}" = 'x' ]
	then
		in_target apt-get -q -y install locales

		gen=false
		for l in $(printf '%s\n' "${locale}" ${supported_locales} | \
				sort -u); do
			if ! LANG=C in_target validlocale "${l}" \
					>>"${target}/etc/locale.gen" 2>/dev/null
			then
				gen=true
			fi
		done
		if ${gen}; then
			in_target locale-gen --keep-existing >/dev/null || \
				return 1
		fi
	fi

	printf 'LANG=%s\n' "${locale}" >"${target}/etc/default/locale"
}

do_tz_setup()
{
	info 'Setting time zone'

	if [ "x${time_zone}" = 'x' ] || ! [ -e \
			"${target}/usr/share/zoneinfo/${time_zone}" ]; then
		err '%s: Invalid time zone' "${time_zone}"
		return 1
	fi

	printf '%s\n' "${time_zone}" >"${target}/etc/timezone"
	cp -f "${target}/usr/share/zoneinfo/${time_zone}" \
		"${target}/etc/localtime"
}

do_user_setup()
{
	local group=
	local f=

	info 'Setting users and passwords'

	in_target shadowconfig "${passwd_shadow}" || return 1

	case "${root_passwd_crypted}" in ?*)
		in_target usermod --password="${root_passwd_crypted}" 'root' \
			|| return 1
	;; esac

	if ${user_make}; then
		in_target adduser --disabled-password \
			--gecos "${user_full_name}" \
			"${user_name}" || return 1
		in_target usermod --password="${user_passwd_crypted}" \
			"${user_name}" || return 1
		in_target chown "${user_name}:${user_name}" \
			"/home/${user_name}" || return 1
		if ! ${root_login}; then
			in_target apt-get -q -y install sudo || return 1
			case " ${user_groups} " in
				*' sudo '*);;
				*)
					user_groups="${user_groups} sudo"
					;;
			esac
			if in_target update-alternatives \
					--display libgksu-gconf-defaults \
					1>/dev/null 2>&1; then
				f='/usr/share/libgksu/debian'
				f="${f}/gconf-defaults.libgksu-sudo"
				in_target update-alternatives \
					--set libgksu-gconf-defaults "${f}" || \
					return 1
				in_target update-gconf-defaults
			fi
			printf 'Aptitude::Get-Root-Command "%s";' \
				'sudo:/usr/bin/sudo' \
				>"${target}/etc/apt/apt.conf.d/00aptitude"
		fi
		for group in ${user_groups}; do
			in_target adduser "${user_name}" "${group}" || return 1
		done
	fi
}

do_debconf_setup()
{
	local owner=
	local name=
	local type=
	local value=

	info 'Preseeding debconf database'

	printf '%s' "${debconf_selections}" | while read owner name type value
	do
		printf '%s %s %s %s\n' "${owner}" "${name}" "${type}" "${value}"
	done | in_target debconf-set-selections
}

do_install_extra()
{
	local i=

	info 'Installing extra packages'

	i=0
	while [ ${i} -lt 3 ]; do
		in_target apt-get -q -y install ${postinst_pkgs} && return 0
		i=$((${i} + 1))
	done

	return 1
}

do_chroot_cleanup()
{
	local mp=

	info 'Cleaning up system'

	for file in /etc/networks /etc/resolv.conf; do
		if [ -f "${target}${file}.REAL" ]; then
			mv "${target}${file}.REAL" "${target}${file}"
		fi
	done

	rm -f "${target}/usr/sbin/policy-rc.d"
	rm -f "${target}/sbin/start-stop-daemon"
	in_target dpkg-divert --quiet --remove \
		--rename '/sbin/start-stop-daemon' || return 1

	case "$(uname -s)" in
		'Linux')
			for mp in 'run' 'dev/pts' 'dev' 'sys' 'proc'; do
				while ! umount "${target}/${mp}"; do
					sleep 1
				done
			done
			;;
	esac

	return 0
}

do_umount()
{
	local fs=
	local mp=
	local type=
	local options=
	local dump=
	local pass=

	info 'Unmounting file systems'

	while read fs mp type options dump pass; do
		case "${type}" in ''|'swap') continue;; esac
		case "${fs}" in
			'@DEV'*'@')
				;;
			*)
				continue
				;;
		esac
		while ! umount "${target}${mp}"; do
			sleep 1
		done
		rmdir "${target}${mp}"
	done <<-EOF
		${fstab}
		EOF

		return 0
}

usage()
{
	printf 'Usage: %s host device\n' "${0}"
}

main()
{
	local host_file=
	local log=

	exec 3>&1

	if [ ${#} -ne 2 ]; then
		usage >&2
		return 1
	fi
	host="${1}"
	host_file="$(dirname "${0}")/hosts/${host}"
	if ! [ -r "${host_file}" ]; then
		err '%s: Unknown host' "${host}"
		return 1
	fi
	dev="${2}"

	. "${host_file}"

	log="$(mktemp)"
	exec 4>"${log}"
	do_ fdisk || return 1
	do_ mkfs || return 1
	do_ mount || return 1
	do_ check_target || { do_ umount; return 1; }
	do_ debootstrap || { do_ umount; return 1; }
	do_ chroot_setup || { do_ umount; return 1; }
	do_ fstab_setup || { do_ chroot_cleanup; do_ umount; return 1; }
	do_ apt_update || { do_ chroot_cleanup; do_ umount; return 1; }
	do_ locale_setup || { do_ chroot_cleanup; do_ umount; return 1; }
	do_ tz_setup || { do_ chroot_cleanup; do_ umount; return 1; }
	do_ user_setup || { do_ chroot_cleanup; do_ umount; return 1; }
	do_ debconf_setup || { do_ chroot_cleanup; do_ umount; return 1; }
	do_ install_extra || { do_ chroot_cleanup; do_ umount; return 1; }
	do_ postinst || { do_ chroot_cleanup; do_ umount; return 1; }
	do_ chroot_cleanup || { do_ umount; return 1; }
	exec 4>&-
	mkdir -p "${target}/var/log/installer"
	mv "${log}" "${target}/var/log/installer/log"
	do_umount || return 1

	exec 3>&-

	return 0
}

main "${@}"