#!/bin/sh
# Check repository for outdated packages

remote_name() {
    # Repology names some packages differently to us. This function fixes
    # any known naming inconsistences that aren't a result of packaging error.
    remote=$(printf %s "$1" | tr '[:upper:]' '[:lower:]')
    remote=${remote%%-bin}
    remote=${remote%%-git}

    case $remote in
        baselayout)
            remote=baselayout-kiss
        ;;

        gtk+[0-9])
            remote=gtk
        ;;

        kiss)
            remote=kiss-package-manager
        ;;

        st)
            remote=st-term
        ;;

        xf86-*)
            remote=xdrv:${remote##*-}
        ;;
    esac
}

remote_ver() {
    # Grab the package's version as known by repology.org by downloading the
    # SVG badge and extracting the version from the XML. This is far simpler
    # to work with rather than using the API directly.
    remote_name "$1"

    rep=$(curl -s "https://repology.org/badge/latest-versions/$remote.svg") && {
        remote_ver=${rep%</text>*}
        remote_ver=${remote_ver##*>}
    }
}

main() {
    [ "$1" ] || {
        printf 'usage: kiss outdated /path/to/repo\n' >&2
        exit 1
    }

    cd "$1" 2>/dev/null || {
        printf 'repository %s is inaccessible\n' "$1" >&2
        exit 1
    }

    printf 'Checking repology.org for outdated packages in %s\n' "$1" >&2

    for pkg in */; do
        pkg=${pkg%%/}

        read -r ver _ 2>/dev/null < "$pkg/version" || {
            printf '%s: local version not found\n' "$pkg" >&2
            continue
        }

        [ "$ver" = git ] && {
            printf '%s: skipping, version is git\n' "$pkg" >&2
            continue
        }

        remote_ver "$pkg" || {
            printf '%s: failed to grab version from repology\n' "$pkg" >&2
            continue
        }

        case $remote_ver in
            *", $ver"* | *"$ver,"* | "$ver")
                # Found match, do nothing.
            ;;

            - | '' | ' ')
                printf '%s: empty response, named correctly?\n' "$pkg" >&2
            ;;

            *)
                printf '%s: %s -> %s\n' "$pkg" "$ver" "$remote_ver"
            ;;
        esac
    done
}

main "$@"