#! /bin/bash

# This file is part of Cockpit.
#
# Copyright (C) 2015 Red Hat, Inc.
#
# Cockpit is free software; you can redistribute it and/or modify it
# under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation; either version 2.1 of the License, or
# (at your option) any later version.
#
# Cockpit is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with Cockpit; If not, see <http://www.gnu.org/licenses/>.

set -ex

out="$1"
base="$2"

redirect_base=$(curl -s -w "%{redirect_url}" "$base" -o /dev/null)
if [ -n "$redirect_base" ]; then
    base="$redirect_base"
fi

# Lookup the newest base image recursively
url="$base"
while [ $# -gt 2 ]; do
    fragment="$3"

    if [ "$fragment" = "sort" ]; then
	    backref="$4"
	    pattern="$5"

	    result="`wget -q -O- $url | grep -oE "$pattern" | sed -E "s/${pattern}/\\\\${backref} \\0/" | sort -V -k1 | tail -1`"
	    fragment="`echo $result | cut -f2 -d' '`"


	    if [ -z "$fragment" ]; then
		echo "Could not find '$pattern' at: $url" >&2
		exit 1
	    fi

	    shift; shift
    fi

    base="$url"
    url="$base/$fragment"

    shift
done

# we link to the file so wget can properly detect if we have already downloaded it
# note that due to mirroring, timestamp comparison can result in unnecessary downloading
out_base="`dirname $out`"
intermediate="$out_base/$fragment"

if [ "$intermediate" != "$out" ]; then
    wget --no-clobber --directory-prefix="$out_base" "$base/$fragment"
    cp "$intermediate" "$out"
else
    rm -f "$out"
    wget --directory-prefix="$out_base" "$base/$fragment"
fi

# Make the image be at least 12 Gig.  During boot, docker-storage-setup
# will grow the partitions etc as appropriate, and atomic.setup will
# explicitly grow the docker pool.

vsize=$(qemu-img info "$out" --output=json | python3 -c 'import json, sys; print(json.load(sys.stdin)["virtual-size"])')

if [ "$vsize" -lt 12884901888 ]; then
    qemu-img resize "$out" 12884901888
fi