{ config, lib, pkgs, ... }:

let
  cfg = config.sydnix.haskell;
in {
  options.sydnix.haskell.enable =
    lib.mkEnableOption "Haskell";

  config = lib.mkIf cfg.enable {
    # Convenient shorthand for quickly opening Haskell REPLs.
    programs.bash.profileExtra =
      builtins.readFile ./haskell/ghc-with-packages.sh;

    home.file.".ghc/ghci.conf".text = ''
      :set prompt "\x1b[38;5;5mλ>\x1b[0m "
      :set prompt-cont "\x1b[38;5;5m|>\x1b[0m "
    '';

    sydnix.impermanence.cache.directories =
      let xdg-cache-dir =
            config.home.cacheHome
              or "${config.home.homeDirectory}/.cache";
      in [
        # We don't want to rebuild Hackage simply due to a reboot, do we?  }:)
        (lib.removePrefix "${config.home.homeDirectory}/"
          "${xdg-cache-dir}/cabal")
        ".stack"
      ];
  };
}