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

let 
    cfg = config.modules.desktop.sway;
    # bash script to let dbus know about important env variables and
    # propagate them to relevent services run at the end of sway config
    # see
    # https://github.com/emersion/xdg-desktop-portal-wlr/wiki/"It-doesn't-work"-Troubleshooting-Checklist
    # note: this is pretty much the same as  /etc/sway/config.d/nixos.conf but also restarts  
    # some user services to make sure they have the correct environment variables
    dbus-sway-environment = pkgs.writeTextFile {
      name = "dbus-sway-environment";
      destination = "/bin/dbus-sway-environment";
      executable = true;

      text = ''
    dbus-update-activation-environment --systemd WAYLAND_DISPLAY XDG_CURRENT_DESKTOP=sway
    systemctl --user stop pipewire pipewire-media-session xdg-desktop-portal xdg-desktop-portal-wlr
    systemctl --user start pipewire pipewire-media-session xdg-desktop-portal xdg-desktop-portal-wlr
        '';
    };

    # currently, there is some friction between sway and gtk:
    # https://github.com/swaywm/sway/wiki/GTK-3-settings-on-Wayland
    # the suggested way to set gtk settings is with gsettings
    # for gsettings to work, we need to tell it where the schemas are
    # using the XDG_DATA_DIR environment variable
    # run at the end of sway config
    configure-gtk = pkgs.writeTextFile {
        name = "configure-gtk";
        destination = "/bin/configure-gtk";
        executable = true;
        text = let
          schema = pkgs.gsettings-desktop-schemas;
          datadir = "${schema}/share/gsettings-schemas/${schema.name}";
        in ''
          export XDG_DATA_DIRS=${datadir}:$XDG_DATA_DIRS
          gnome_schema=org.gnome.desktop.interface
          gsettings set $gnome_schema gtk-theme 'Dracula'
          '';
    };

in {
  options.modules.desktop.sway.enable = lib.mkEnableOption "sway";
  config = lib.mkIf cfg.enable {

    environment.systemPackages = with pkgs; [
      sway
      dbus-sway-environment
      wayland
      configure-gtk
      xdg-utils # for opening default programs when clicking links
      glib # gsettings
      dracula-theme # gtk theme
      gnome3.adwaita-icon-theme  # default gnome cursors
      swaylock
      swayidle
      grim # screenshot functionality
      wl-clipboard # wl-copy and wl-paste for copy/paste from stdin / stdout
      mako # notification system developed by swaywm maintainer
      wdisplays # tool to configure displays
      rofi
    ];

    # xdg-desktop-portal works by exposing a series of D-Bus interfaces
    # known as portals under a well-known name
    # (org.freedesktop.portal.Desktop) and object path
    # (/org/freedesktop/portal/desktop).
    # The portal interfaces include APIs for file access, opening URIs,
    # printing and others.
    services.dbus.enable = true;
    xdg.portal = {
      enable = true;
      wlr.enable = true;
      # gtk portal needed to make gtk apps happy
      extraPortals = [ pkgs.xdg-desktop-portal-gtk ];
    };

    # enable sway window manager
    programs.sway = {
      enable = true;
      wrapperFeatures.gtk = true;
    };
  };
}