#!/bin/bash

mode=$1
target=$2
source=$3

wget="wget -q -t0"
arch=$(uname -m)

usage() {
	exec >&2 &&
	echo "usage: $(basename $0) <ftp|cd> <target> [source]" &&
	echo &&
	echo "This script is for installing Arch Linux after manually partitioning and" &&
	echo "network configuration." &&
	exit 1
}

[ "$mode" == "" ] || [ "$target" == "" ] && usage
[ "$mode" == "ftp" ] || [ "$mode" == "cd" ] || usage

[ "$UID" != "0" ] &&
	echo "run as root, please." >&2 &&
	exit 1

[ $(echo $target | egrep ^/) ] ||
	target=$(pwd)/$target

[ -d "$target" ] ||
	mkdir -p $target

[ "$source" == "" ] &&
	source=ftp://ftp.archlinux.org/current/os/$arch ||
	arch=$(basename $source)

[ -f /etc/arch-release ] &&
	on_arch=true

cache=$target/var/cache/pacman/pkg
[ $on_arch ] && {
	mkdir -p $(dirname $cache)
	ln -s /var/cache/pacman/pkg $cache
} || {
	mkdir -p $cache
}

[ "$mode" == "ftp" ] && {
	install() {
		cd $cache
		echo "  · $1"
		exec 2>/dev/null # seems to catch not only 2
		package=$(ls $1*.tar.gz | tail -1)
		[ -f "$package" ] && {
			tar xzf $package -C $target ||
			exit 1
		} || {
			$wget $source/$1*.tar.gz &&
			tar xzf $1*.tar.gz -C $target ||
			exit 1
		}
	}
}
[ "$mode" == "cd" ] && {
	install() {
		exit 1
	}
}

[ $on_arch ] || {
	echo · downloading and installing bash.
		for package in glibc ncurses readline bash; do
			install $package
		done
}

echo · downloading and installing pacman.
	for package in libdownload libarchive acl attr zlib bzip2 pacman; do
		install $package
	done

echo · installing base.
	cd $target
	cp /etc/resolv.conf etc/resolv.conf

	mkdir sys proc dev 2> /dev/null

	[ $on_arch ] && {
		pacman --noconfirm -r $target -Sfy base
	} || {
		mount -o bind /dev dev
		mount -t proc none proc
		mount -t sysfs none sys

		chroot $target /bin/bash <<EOF
			pacman --noconfirm -Sfy base
EOF
	}

echo · cleaning up.
	[ -h $cache ] && rm $cache && mkdir $cache
	[ $on_arch ] || umount sys proc dev
	mv etc/resolv.conf.pacorig etc/resolv.conf
	rm -f etc/*.pac*
	ln -s . boot/boot