{
    config,
    ...
}: let
    inherit (config.poz.other.system) username;

    # https://specifications.freedesktop.org/basedir-spec/latest/
    XDG_CACHE_HOME = "$HOME/.cache";
    XDG_CONFIG_HOME = "$HOME/.config";
    XDG_DATA_HOME = "$HOME/.local/share";
    XDG_STATE_HOME = "$HOME/.local/state";
in {
    # most of the random ass env vars taken from `pkgs.xdg-ninja`
    environment.sessionVariables = {
        inherit
            XDG_CACHE_HOME
            XDG_CONFIG_HOME
            XDG_DATA_HOME
            XDG_STATE_HOME
        ;

        ANDROID_HOME = "${XDG_DATA_HOME}/android";
        CARGO_HOME = "${XDG_DATA_HOME}/cargo";
        DOTNET_CLI_HOME = "${XDG_DATA_HOME}/dotnet";
        GOPATH = "${XDG_DATA_HOME}/go";
        GNUPGHOME = "${XDG_DATA_HOME}/gnupg";
        GRADLE_USER_HOME = "${XDG_DATA_HOME}/gradle";
        HISTFILE = "${XDG_STATE_HOME}/bash/history";
        MYSQL_HISTFILE = "${XDG_STATE_HOME}/mysql/history";
        NPM_CONFIG_USERCONFIG = "${XDG_CONFIG_HOME}/npm/npmrc";
        NUGET_PACKAGES = "${XDG_CACHE_HOME}/NuGetPackages";
        _JAVA_OPTIONS = "-Djava.util.prefs.userRoot=${XDG_CONFIG_HOME}/java";
        PARALLEL_HOME = "${XDG_CONFIG_HOME}/parallel";
        PYTHONSTARTUP = "${XDG_CONFIG_HOME}/python/pythonrc";
        RUSTUP_HOME = "${XDG_DATA_HOME}/rustup";
        WINEPREFIX = "${XDG_DATA_HOME}/wine";
        XAUTHORITY = "\$XDG_RUNTIME_DIR/Xauthority";
    };

    poz.programs.zsh.extraAliases = {
        gdb = "gdb -n -x ${XDG_CONFIG_HOME}/gdb/init";
        pidgin = "pidgin --config=${XDG_DATA_HOME}/purple";
        svn = "svn --config-dir ${XDG_CONFIG_HOME}/subversion";
        wget = "wget --hsts-file=\"${XDG_DATA_HOME}/wget-hsts\"";
    };

    home-manager.users.${username} = {
        xdg = {
            configFile = {
                "npm/npmrc".text = ''
                    prefix=${XDG_DATA_HOME}/npm
                    cache=${XDG_CACHE_HOME}/npm
                    tmp=\$XDG_RUNTIME_DIR/npm
                    init-module=${XDG_CONFIG_HOME}/npm/config/npm-init.js
                '';

                "python/pythonrc".text = ''
                    import os
                    import atexit
                    import readline

                    history = os.path.join(os.environ['XDG_CACHE_HOME'], 'python_history')
                    try:
                        readline.read_history_file(history)
                    except OSError:
                        pass

                    def write_history():
                        try:
                            readline.write_history_file(history)
                        except OSError:
                            pass

                    atexit.register(write_history)
                '';
            };

            cacheHome = XDG_CACHE_HOME;
            configHome = XDG_CONFIG_HOME;
            dataHome = XDG_DATA_HOME;
            stateHome = XDG_STATE_HOME;
            mimeApps = {
                enable = true;
                defaultApplications = let
                    primary_browser = "firefox-schizo.desktop";
                    secondary_browser = "firefox-unschizo.desktop";
                    mail_client = "thunderbird.desktop";
                    file_manager = "pcmanfm.desktop";
                    media_player = "mpv.desktop";
                    image_viewer = "imv.desktop";
                    text_editor = "nvim.desktop";
                in{
                    "text/html" = [ primary_browser secondary_browser ];
                    "x-scheme-handler/http" = [ primary_browser secondary_browser ];
                    "x-scheme-handler/https" = [ primary_browser secondary_browser ];
                    "x-scheme-handler/about" = [ primary_browser secondary_browser ];
                    "x-scheme-handler/unknown" = [ primary_browser secondary_browser ];
                    "x-scheme-handler/mailto" = [ mail_client ];
                    "message/rfc822" = [ mail_client ];
                    "x-scheme-handler/mid" = [ mail_client ];
                    "inode/directory" = [ file_manager ];
                    "x-scheme-handler/heroic" = [ "heroic.desktop" ];
                    "audio/mp3" = [ media_player ];
                    "audio/ogg" = [ media_player ];
                    "audio/mpeg" = [ media_player ];
                    "audio/aac" = [ media_player ];
                    "audio/opus" = [ media_player ];
                    "audio/wav" = [ media_player ];
                    "audio/webm" = [ media_player ];
                    "audio/3gpp" = [ media_player ];
                    "audio/3gpp2" = [ media_player ];
                    "video/mp4" = [ media_player ];
                    "video/x-msvideo" = [ media_player ];
                    "video/mpeg" = [ media_player ];
                    "video/ogg" = [ media_player ];
                    "video/mp2t" = [ media_player ];
                    "video/webm" = [ media_player ];
                    "video/3gpp" = [ media_player ];
                    "video/3gpp2" = [ media_player ];
                    "image/png" = [ image_viewer ];
                    "image/jpeg" = [ image_viewer ];
                    "image/gif" = [ media_player ];
                    "image/avif" = [ image_viewer ];
                    "image/bmp" = [ image_viewer ];
                    "image/vnd.microsoft.icon" = [ image_viewer ];
                    "image/svg+xml" = [ image_viewer ];
                    "image/tiff" = [ image_viewer ];
                    "image/webp" = [ image_viewer ];
                    "text/plain" = [ text_editor ];
                };
            };
        };
    };
}