{ config, pkgs, lib, ... }:
let
  cfg = config.my.home.shell;
  aliases = config.my.home.shell.aliases;
in
{
  config = lib.mkIf (cfg.name == "zsh") {
    home.packages = with pkgs; [ zsh-completions ];

    programs.zsh = {
      enable = true;
      dotDir = ".config/zsh";
      enableCompletion = true;

      history = {
        size = 500000;
        save = 500000;
        extended = false;
        ignoreSpace = true;
        ignoreDups = true;
        share = false;
        # see
        # https://github.com/nix-community/home-manager/blob/32a7da69dc53c9eb5ad0675eb7fdc58f7fe35272/modules/programs/zsh.nix#L537
        path = ".local/share/zsh/zsh_history";
      };

      localVariables = {
        # Print timing statistics for everything which takes longer than 5 seconds of
        # user + system time.
        REPORTTIME = 5;
      };

      shellAliases = aliases;

      defaultKeymap = "emacs";

      # the order matters for sway.zsh: I want to load it first
      # to start the session if I log on a machine where it's
      # available.
      # it can't be loaded with `initExtraFirst` because the session
      # variables from home-manager are not set yet otherwise (and I
      # need them for things like firefox or emacs).
      initExtra = lib.concatMapStrings builtins.readFile [
        ./sway.zsh
        ./completion-style.zsh
        ./options.zsh
        ./prompt.zsh
        ./tmux.zsh
      ];
    };
  };
}