#!/bin/sh
set -e

usage() {
    echo >&2 "usage: $0 [options] file.dsc"
    echo >&2 "  -s         Sign"
    echo >&2 "  -u DPUT    Upload"
    echo >&2 "  -f         Force dput"
    echo >&2 "  -D SERIES  Distroseries (REQUIRED)"
    exit 2
}
sign=
dput=
forcedput=
series=
while getopts su:fD: OPTION; do
    case $OPTION in
        s) sign=1;;
        u) dput=$OPTARG;;
        f) forcedput=1;;
        D) series=$OPTARG;;
        \?) usage;;
    esac
done
shift $(($OPTIND - 1))
if [ $# -ne 1 ] || [ -z "$series" ]; then
    usage
fi
dscfile=$1
shift

tmpdir="tmp.backport.$series.$$"

# Extract
dpkg-source -x "$dscfile" "$tmpdir"

# Tweak changelog
cd "$tmpdir"
dch --distributor not-ubuntu -D "$series" -b -l "~bazaar1~$series" "Rebuild in PPA for $series."

# Trivial source format downgrade magic
if [ -f debian/source/format ]; then
    case $series in
        hardy|jaunty)
            if [ -d debian/patches ]; then
                echo "AUTOMATIC REVERT TO SOURCE FORMAT 1.0, PATCHES BUNDLED AS diff.gz"
                dch -a "Reverted to source format 1.0, all of debian/patches/ bundles as the .diff.gz."
                rm -r .pc debian/patches
                rm debian/source/format
            else
                echo "AUTOMATIC REVERT TO SOURCE FORMAT 1.0"
                dch -a "Trivially reverted to source format 1.0."
                rm debian/source/format
            fi
            ;;
    esac
fi

cd ..

# Package up again
dpkg-source -i -b "$tmpdir"

# Generate a .changes
cd "$tmpdir"
package=`dpkg-parsechangelog | sed -nr 's/^Source: //p'`
version=`dpkg-parsechangelog | sed -nr 's/^Version: //p'`
dpkg-genchanges -S -sd > "../${package}_${version}_source.changes"
cd ..

# Clean up
rm -rf "$tmpdir"

if [ "$sign" ]; then
    debsign "${package}_${version}_source.changes"
fi
if [ "$dput" ]; then
    dput ${forcedput+-f} "$dput" "${package}_${version}_source.changes"
fi