#!/bin/bash

set -euo pipefail

KEEP_V_R=

while [ $# -gt 0 ]; do

    case "$1" in

        -h | --help)

            echo "Usage: $0 [--keep-v-r]" >&2

            exit 0

            ;;

        --keep-v-r)

            KEEP_V_R=1

            ;;

        *)

            echo "$0: unrecognized option: $1" >&2

            exit 1

            ;;

    esac

    shift

done

main() {

    local upstream

    upstream=$(get_parsed_spec_field URL)

    curl -Lo rpm-ostree.spec.new "$upstream/raw/main/packaging/rpm-ostree.spec.in"

    # remove dummy changelog from upstream spec

    sed -i -e '/%changelog/Q' rpm-ostree.spec.new

    # append real changelog to upstream spec

    sed -ne '/%changelog/,$ p' rpm-ostree.spec >> rpm-ostree.spec.new

    if [ -n "${KEEP_V_R}" ]; then

        local version release

        version=$(get_raw_spec_field Version)

        release=$(get_raw_spec_field Release)

        sed -ie "s/^Version:.*/Version: $version/" rpm-ostree.spec.new

        sed -ie "s/^Release:.*/Release: $release/" rpm-ostree.spec.new

    fi

    if git diff --quiet --exit-code rpm-ostree.spec; then

        mv rpm-ostree.spec.new rpm-ostree.spec

        echo "Updated rpm-ostree.spec" >&2

    else

        echo "Refusing to overwrite dirty rpm-ostree.spec" >&2

        echo "Updated rpm-ostree.spec.new" >&2

    fi

}

get_parsed_spec_field() {

    rpmspec -P rpm-ostree.spec | grep "^${1}: " | head -n1 | cut -d ' ' -f 2

}

get_raw_spec_field() {

    grep "^${1}: " rpm-ostree.spec | head -n1 | cut -d ' ' -f 2

}

main "$@"