#!/bin/bash
#   Copyright (C) 2013  Red Hat, Inc.
#   Copyright (C) 2015  Till Maas
#   Copyright (C) 2016  Ben Rosser
#
#   This program is free software: you can redistribute it and/or modify
#   it under the terms of the GNU General Public License as published by
#   the Free Software Foundation, either version 3 of the License, or
#   (at your option) any later version.
#
#   This program 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 General Public License for more details.
#
#   You should have received a copy of the GNU General Public License
#   along with this program.  If not, see <http://www.gnu.org/licenses/>.

# Abort on errors
set -e

baseurl=http://pkgs.rpmfusion.org/repo/pkgs
pkgname=$(basename $PWD)

# Determine if the package is in free or in nonfree.
# If we fail for whatever reason (.git/config not present, remote info not
# in that file) we'll attempt to download both.
namespace=""
if [[ -s .git/config ]]; then
    remote_string=`grep pkgs.rpmfusion.org .git/config`
    namespace="free"
    if [[ $remote_string == *"nonfree"* ]]; then
        namespace="nonfree"
    elif [[ $remote_string == *"free"* ]]; then
        namespace="free"
    fi
fi

# Download sources.
if [[ -s sources ]]; then
    while read md5sum tarball; do

        # Pick the type of hash by looking at the length of the sum.
        hashtype=""
        sumlength=`echo -n $md5sum | wc -m`
        case $sumlength in
            32)  hashtype="md5" ;;
            40)  hashtype="sha1" ;;
            56)  hashtype="sha224" ;;
            64)  hashtype="sha256" ;;
            96)  hashtype="sha384" ;;
            128) hashtype="sha512" ;;
            *)   echo "Error: unrecognized hash function when downloading file ${tarball} with checksum ${md5sum}"
                 exit 1 ;;
            esac

        # Now, attempt download depending on the value of namespace.
        # Unset = attempt to download from all namespaces, error if they all fail.
        # Note that the list of all namespaces here needs to be updated if/when new namespaces are added.
        if [[ $namespace == "" ]]; then
            curl -H Pragma: -o ./$tarball -R -S --fail $baseurl/free/$pkgname/$tarball/$hashtype/$md5sum/$tarball || true
            curl -H Pragma: -o ./$tarball -R -S --fail $baseurl/nonfree/$pkgname/$tarball/$hashtype/$md5sum/$tarball || true

            # Unfortunately we *also* need to try and download wihout $hashtype, if the hash is MD5
            # This is support for legacy entries in the lookaside cache
            # Only do this if we failed to download already.
            if [[ $hashtype == "md5" ]] && [ ! -f ./$tarball ]; then
                curl -H Pragma: -o ./$tarball -R -S --fail $baseurl/free/$pkgname/$tarball/$md5sum/$tarball || true
                curl -H Pragma: -o ./$tarball -R -S --fail $baseurl/nonfree/$pkgname/$tarball/$md5sum/$tarball || true
            fi
        # If the namespace variable is set, use it to determine what to download.
        else
            curl -H Pragma: -o ./$tarball -R -S --fail $baseurl/$namespace/$pkgname/$tarball/$hashtype/$md5sum/$tarball || true

            # Unfortunately we *also* need to try and download wihout $hashtype, if the hash is MD5
            # This is support for legacy entries in the lookaside cache
            # Only do this if we failed to download already.
            if [[ $hashtype == "md5" ]] && [ ! -f ./$tarball ]; then
                curl -H Pragma: -o ./$tarball -R -S --fail $baseurl/$namespace/$pkgname/$tarball/$md5sum/$tarball || true
            fi
        fi

        # Complain if the download failed (i.e. file not present) and exit.
        if [ ! -f ./$tarball ]; then
            echo "Error: download of ${tarball} failed."
            exit 1
        fi

        # Check each line in the file individually in case files *don't* consistently
        # use the same set of checksums.
        # Since each checksum program consists of the name of the checksum followed by
        # the string 'sum', we can avoid reproducing the above table.
        echo "${md5sum} ${tarball}" | ${hashtype}sum -c

    done < sources
fi