nix-conf/user/xdg.nix

{
  config,
  pkgs,
  ...
}: {
  xdg.mimeApps.enable = true;
  xdg.mimeApps.defaultApplications = let
    image = "nsxiv-rifle.desktop";
    browser = "firefox.desktop";
    text = "nvim.desktop";
    media = "mpv.desktop";
  in {
    "image/jpeg" = image;
    "image/png" = image;
    "image/gif" = image;

    "audio/mpeg" = media;
    "audio/ogg" = media;
    "audio/vorbis" = media;
    "audio/x-vorbis+ogg" = media;

    "video/mp4" = media;
    "video/mpeg" = media;

    "text/plain" = text;
    "application/xml" = text;

    "inode/directory" = "org.kde.dolphin.desktop";
  };
  xdg.portal = {
    enable = true;
    configPackages = [pkgs.libsForQt5.xdg-desktop-portal-kde];
    extraPortals = [pkgs.libsForQt5.xdg-desktop-portal-kde];
    config.common.default = "kde";
  };
  home.file = let
    mkln = x: config.lib.file.mkOutOfStoreSymlink "${config.home.homeDirectory}/${x}";
  in {
    ".local/home/.cache".source = mkln ".cache";
    ".local/home/.config".source = mkln ".config";
    ".local/home/.local".source = mkln ".local";
    ".local/home/Desktop".source = mkln "Desktop";
    ".local/home/Downloads".source = mkln "Downloads";
  };
}