#!/bin/sh
# dl-lp-chroot - download a chroot tarball from Launchpad
# Copyright (C) 2010 Loïc Minier <lool@dooz.org>
#
# Permission is hereby granted, free of charge, to any person obtaining a
# copy of this software and associated documentation files (the "Software"),
# to deal in the Software without restriction, including without limitation
# the rights to use, copy, modify, merge, publish, distribute, sublicense,
# and/or sell copies of the Software, and to permit persons to whom the
# Software is furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
# SOFTWARE IN THE PUBLIC INTEREST, INC. BE LIABLE FOR ANY CLAIM, DAMAGES OR
# OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
# ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
# DEALINGS IN THE SOFTWARE.
#
# Except as contained in this notice, the name of the author shall not be used
# in advertising or otherwise to promote the sale, use or other dealings in
# this Software without prior written authorization from the author.
#
# depends: wget

set -e

self="$(basename "$0")"
arch="`dpkg --print-architecture`"
dist="`lsb_release -cs`"
output_file=""

usage() {
    echo "Usage: $self [--arch <arch>] [--dist <dist>] [-O output-file]" >&2
}

die() {
    echo "$*" >&2
    exit 1
}

if ! which wget >/dev/null; then
    die "Please install wget"
fi

while [ $# -gt 0 ]; do
    case "$1" in
      --help)
        usage
        exit 0
      ;;
      --arch)
        arch="$2"
        if [ -z "$arch" ]; then
            die "Empty arch argument"
        fi
        shift 2
      ;;
      --dist)
        dist="$2"
        if [ -z "$dist" ]; then
            die "Empty dist argument"
        fi
        shift 2
      ;;
      -O)
        output_file="$2"
        if [ -z "$output_file" ]; then
            die "Empty output file argument"
        fi
        shift 2
      ;;
      *)
        die "Unknown argument $1"
      ;;
    esac
done

chroot_url="`wget -q -O - "https://launchpad.net/api/devel/ubuntu/$dist/$arch/chroot_url" | tr -d '"'`"

exec wget ${output_file:+-O "$output_file"} "$chroot_url"