#!/bin/bash
# Copyright 2007 (C) Terence Simpson <stdin@stdin.me.uk>
# Modified by Siegfried-A. Gevatter <rainct@ubuntu.com>
# License: GPLv2 or later
#
# This script simulates «dget»'s behaviour for files hosted at
# launchpadlibrarian.net.
#
# Detailed description:
# This script attempts to download the source package in the same
# way as dget does, but from launchpadlibrarian.net, which doesn't
# store all the files in the same directory. It (the script) assumes
# that the files are stored in sequential directories on Launchpad
# Librarian and attemps to download and then unpack them.

GET="wget"
UNPACK="dpkg-source -x {dsc-file}"

usage()
{
cat << EOF
Usage: $0 [-d] <Launchpad URL>

This scripts simulates «dget»'s behaviour for files hostead at
launchpadlibrarian.net.

If you specify the -d option then it won't do anything, but just
print the commands it would run otherwise.

Example:
	$0 http://launchpadlibrarian.net/10348157/coreutils_5.97-5.4ubuntu1.dsc
EOF
}

if [ $1 ] && [ $1 = "-d" ] || [ $1 = "--debug" ]
then
	# Debug Mode
	GET="echo "${GET}
	UNPACK="echo "${UNPACK}
	shift
fi

if [ $1 ] && [ $1 = "-h" ] || [ $1 = "--help" ]
then
	usage
	exit 0
fi

if [ $# -ne 1 ]
then
	usage
	exit 1
fi

# Store download URL into a local variable to be able to modify it
URL=$1

if [ ${URL:0:4} == 'www.' ]
then
	URL="http://"${URL:4}
fi

if [ ${URL:0:7} != 'http://' ]
then
	URL="http://"$URL
fi

if [ ${URL:0:30} != 'http://launchpadlibrarian.net/' ]
then
	echo "Error: This utility only works for files on launchpadlibrarian.net."
	exit 1
fi

if [ ${URL##*.} !=  'dsc' ]
then
	echo "You have to provide the URL for the .dsc file."
	exit 1
fi

BASE="http://launchpadlibrarian.net" #BASE="http://$(echo $URL|cut -d '/' -f 3)"
NUMBER="$(echo $URL|cut -d '/' -f 4)"
FILE="$(echo $URL|cut -d '/' -f 5)"

UNPACK=$(echo $UNPACK | sed s/{dsc-file}/${FILE}/g)

echo "Getting ${BASE}/${NUMBER}/${FILE}"
if ! $GET ${BASE}/${NUMBER}/${FILE}
then
	echo "Failed to fetch «.dsc» file, aborting."
	exit 1
fi

echo "Getting ${BASE}/$(($NUMBER-1))/$(echo $FILE|sed 's,\.dsc$,.diff.gz,')"
if ! $GET ${BASE}/$(($NUMBER-1))/$(echo $FILE | sed 's,\.dsc$,.diff.gz,')
then
	echo "Failed to fetch «.diff.gz» file, aborting."
	exit 1
fi

echo "Getting ${BASE}/$(($NUMBER-2))/$(echo $FILE|sed 's,\-[0-9]*.*$,.orig.tar.gz,')"
if ! $GET ${BASE}/$(($NUMBER-2))/$(echo $FILE|sed 's,\-[0-9]*.*$,.orig.tar.gz,')
then
	echo "Failed to fetch «orig.tar.gz» file, aborting."
	exit 1
fi

if ! $UNPACK
then
	echo "Failed to unpack source, aborting."
	exit 1
fi