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

with lib;

let
  addToXDGDirs = p: ''
    if [ -d "${p}/share/gsettings-schemas/${p.name}" ]; then
      export XDG_DATA_DIRS=$XDG_DATA_DIRS''${XDG_DATA_DIRS:+:}${p}/share/gsettings-schemas/${p.name}
    fi
    if [ -d "${p}/lib/girepository-1.0" ]; then
      export GI_TYPELIB_PATH=$GI_TYPELIB_PATH''${GI_TYPELIB_PATH:+:}${p}/lib/girepository-1.0
      export LD_LIBRARY_PATH=$LD_LIBRARY_PATH''${LD_LIBRARY_PATH:+:}${p}/lib
    fi
  '';
in {
  environment.systemPackages = with pkgs; [
    orca
    glib.bin
  ];
  services.gnome3.at-spi2-core.enable = true;
  services.xserver = {
    desktopManager.mate.enable = true;
    displayManager = {
      gdm = {
        enable = true;
        autoSuspend = false;
        autoLogin = {
          enable = true;
          user = "nixos";
        };
      };
      sessionCommands = ''
        if test "$XDG_CURRENT_DESKTOP" = "MATE"; then
            export XDG_MENU_PREFIX=mate-
            # Let caja find extensions
            export CAJA_EXTENSION_DIRS=$CAJA_EXTENSION_DIRS''${CAJA_EXTENSION_DIRS:+:}${config.system.path}/lib/caja/extensions-2.0
            # Let caja extensions find gsettings schemas
            ${concatMapStrings (p: ''
            if [ -d "${p}/lib/caja/extensions-2.0" ]; then
                ${addToXDGDirs p}
            fi
            '') config.environment.systemPackages}
            # Add mate-control-center paths to some XDG variables because its schemas are needed by mate-settings-daemon, and mate-settings-daemon is a dependency for mate-control-center (that is, they are mutually recursive)
            ${addToXDGDirs pkgs.mate.mate-control-center}
            # Auto start orca screen-reader
            GSETTINGS_BACKEND=dconf ${pkgs.glib.bin}/bin/gsettings set org.gnome.desktop.a11y.applications screen-reader-enabled true
            GSETTINGS_BACKEND=dconf ${pkgs.glib.bin}/bin/gsettings set org.mate.interface accessibility true
            GSETTINGS_BACKEND=dconf ${pkgs.glib.bin}/bin/gsettings set org.mate.applications-at-visual startup true
            export GTK_MODULES=gail:atk-bridge
        fi
      '';
    };
  };
}