shell.nix

{ pkgs ? import <nixpkgs> { }, nixpkgs ? <nixpkgs>, }:
let
  inherit (pkgs.lib) optional optionals;
  erlang = pkgs.beam.interpreters.erlangR25;
  elixir = pkgs.beam.packages.erlangR25.elixir_1_14;
in pkgs.mkShell rec {
  name = "advent-of-code-shell";
  buildInputs = with pkgs;
    [
      git

      shellcheck
      shfmt

      nil
      nixfmt

      rebar
      rebar3
      erlang

      elixir
      elixir_ls

      gleam
      tree-sitter
    ] ++ optional stdenv.isLinux inotify-tools ++ optionals stdenv.isDarwin
    (with darwin.apple_sdk.frameworks; [ CoreFoundation CoreServices ]);
  shellHook = ''
    # this allows mix to work on the local directory
    mkdir -p .nix-mix
    mkdir -p .nix-hex
    export MIX_HOME=$PWD/.nix-mix
    export HEX_HOME=$PWD/.nix-hex
    export PATH=$MIX_HOME/bin:$PATH
    export PATH=$HEX_HOME/bin:$PATH
    export LANG=en_US.UTF-8
    export ERL_AFLAGS="-kernel shell_history enabled"
    export ERL_LIBS=""
  '';
}