#! /usr/bin/env sh

main() {
    use_running="$1"
    host="$2"
    package="$3"

    if [ "$use_running" = "true" ]; then
        base="/run/current-system"
    else
        base=".#nixosConfigurations.$host.config.system.build.toplevel"
    fi

    fd "[a-zA-Z0-9]{32}-$package" /nix/store --type directory --threads 1 --exec nix --option warn-dirty false why-depends "$base"
}

running=false
host="$(hostname)"
packages=""
direct_packages=""

while [ "$#" -ne 0 ]; do
    case "$1" in
    "--running")
        running=true
        ;;
    "--host")
        shift 1
        host="$1"
        ;;
    "--direct")
        shift 1
        direct_packages="$direct_packages $1"
        ;;
    *)
        # Treat everything else as a package to check
        packages="$packages $1"
        ;;
    esac

    shift 1
done

if [ -n "$packages" ]; then
    for package in $packages; do
        main "$running" "$host" "$package-"
    done
fi

if [ -n "$direct_packages" ]; then
    for package in $direct_packages; do
        main "$running" "$host" "$package-[0-9]"
    done
fi

# vim: ft=sh