{ inputs, lib, ... }:
let
  inherit (lib)
    filterAttrs
    mapAttrsToList
    concatStringsSep
    ;
in
{
  flake.overlays.rolling_datasets =
    final: prev:
    let
        writeShellScript = name: text:
          prev.writeTextFile {
            inherit name;
            executable = true;
            text = ''
              #!/bin/sh
              ${text}
            '';
            checkPhase = ''
              ${prev.stdenv.shellDryRun} "$target"
            '';
          };
    in
      {
        rolling_datasets =
          final.runCommand "rolling_datasets" {

          } ''
            mkdir -p $out/bin
            mkdir -p $out/share/functions
            export runtimeShell=${prev.runtimeShell} \
                   runtimePath=${prev.lib.makeBinPath (with prev; [ utillinux zfs ])}

            ${concatStringsSep "\n" (mapAttrsToList (name: _: ''
            {
              binary=${writeShellScript name (builtins.readFile (./. + "/bin/${name}"))}
              output_binary="$out/bin/${name}"
              substituteAll "$binary" "$output_binary"
              chmod +x "$output_binary"
            }
            '') (filterAttrs (_: v: v == "regular") (builtins.readDir ./bin)))}

            for function in ${./functions}/* ; do
              substituteAll "$function" "$out/share/functions/$(basename "$function")"
            done
          '';
      };
}