#!/bin/sh

set -e

mirror="http://mirror.nl.leaseweb.net/slackware/"
release="slackware64-current" # "slackware-current", "slackware64-current"
url="$mirror/$release/slackware64" # "slackware", "slackware64"
filelist="$url/FILE_LIST"
pkgtools="pkgtools-14.1-noarch-2.tgz"
pkgtoolsurl="$url/a/$pkgtools"
root="/ns/$release"
test x"$1" != x"" && root="$1"
tmpdir="/tmp/slackware/$release"
pkgdir="$tmpdir/pkgs"

# a template file is just a plain-text file with a package per line.
templateurl="http://git.2f30.org/templates/plain/minimal-server.template"
templatefile="$tmpdir/template"

tar113="$tmpdir/tar-1.13"
tar113url="http://www.codemadness.nl/downloads/morpheus/slackware/tar-1.13.gz"
tar113checksum="b121b4d03e5ac37fa601f3edf44a80ad1782316442a69372ec1ab33871369780150dffe2d9c67459cbe90ea3ee33a1ea566e57a7b5d63cab08655e2b5220858a  tar-1.13"

mkdir -p "$tmpdir"
cd "$tmpdir"

# get precompiled tar-1.13 required by installpkg (static i486 glibc binary).
# NOTE: if you want to build tar-1.13 yourself, the source is available at:
# http://mirror.nl.leaseweb.net/slackware/slackware-current/source/a/tar/tar-1.13.tar.gz
# build instructions:
# ./configure --disable-nls; make CC="gcc -static"; strip src/tar; <copy src/tar>.
if ! test -f "$tar113"; then
	wget "${tar113url}" -O - | gunzip -c - > "${tar113}"
	printf '%s' "$tar113checksum" | sha512sum -c -
fi

# make sure this tar version is in $PATH and preferred.
export PATH="${tmpdir}:$PATH"
chmod "755" "$tar113"
ln -sf "$tar113" "tar"

# get template of packages to install.
if ! test -f "$templatefile"; then
	wget "$templateurl" -O "$templatefile"
fi

# get pkgtools.
installpkg="$tmpdir/sbin/installpkg"
if ! test -f "$pkgtools"; then
	wget "${pkgtoolsurl}" -O "$tmpdir/$pkgtools"
fi
if ! test -f "$installpkg"; then
	tar -xzf "$tmpdir/$pkgtools"
fi

# get packages.
mkdir -p "$pkgdir"
cd "$pkgdir"
wget "$filelist" -q -O - | grep -E -o '[^ ]*$' | grep -E '\.(txz|tgz|txt|asc)$' | while read -r line; do
	pset=$(dirname "$line" | sed 's@[^a-z]*@@g')
	pfilename=$(basename "$line")
	# strip version part of name for matching (this should be fine in most cases).
	pname=$(printf '%s' "${pfilename}" | sed -E 's@^([^-]*-?[a-z]*?)-.+@\1@g')
	pattern="^${pname}\$"

	if grep -qE "$pattern" "$templatefile"; then
		mkdir -p "$pset"
		if ! test -f "$pset/$pfilename"; then
			wget "$url/$line" -O "$pset/$pfilename"
		fi
	fi
done

# install package sets in order.
mkdir -p "$root"
cd "$pkgdir"
for pset in *; do
	find "$pset" -name "*.t?z" | while read -r f; do
		"$installpkg" --terse --root "$root" "$f"
	done
done

# fix symlink references for libs.
libdir="$root/lib64"
if ! test -d "$libdir"; then
	libdir="$root/lib"
fi
cd "$libdir"
for i in *; do
    if readlink "$i" | grep -qE '\.incoming$'; then
        r=$(basename "$(readlink "$i" | sed -E 's@\.incoming$@@')")
        if test -L "$i"; then
            ln -sf "$r" "$i"
        fi
    fi
done

# copy /etc/resolv.conf
mkdir -p "${root}/etc"
cp /etc/resolv.conf "${root}/etc/resolv.conf"
chmod 644 "${root}/etc/resolv.conf"