#!/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 "$@"