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

{
  # Convenient shorthand for quickly opening Haskell REPLs.
  programs.bash.profileExtra = ''
    # Start a GHCi REPL with the given packages made available.
    ghci-with-packages () {
      nix-shell -p "haskellPackages.ghcWithPackages (p: with p; [ $@ ])" \
        --run ghci
    }

    # Run GHC with the given packages made available.
    ghc-with-packages () {
      getopt -o "p" -- "$@"
      while true; do
        case "$1" in
          -p)
            packages="$1"
            shift 2
            ;;
          --)
            shift
            break
            ;;
        esac
      done

      if [ $? -ne 0 ]; then
       echo "Invalid options provided"
       exit 1
      fi

      eval set -- "$options"

      nix-shell -p "haskellPackages.ghcWithPackages (p: with p; [ $packages ])" \
        --run "ghc $@"
    }
  '';

  # Some global Cabal configuration.
  xdg.configFile.".cabal/config".text = ''
    -- Globally-enable Nix integration.  See
    -- https://cabal.readthedocs.io/en/3.4/nix-integration.html
    nix: True
  '';
}