moonix/modules/browsers.nix

# ABOUTME: Firefox with its preconfiguration, and Chromium as the second browser.
# ABOUTME: Carries the default-handler registration the two of them make necessary.

{ pkgs, moonarchPkgs, ... }:

let
  # The Firefox theme's add-on ID, read twice below: once to install the theme,
  # once to select it. This is upstream Catppuccin's own build; the similarly
  # named catppuccin-mocha on the same store belongs to a third party.
  catppuccinThemeId = "{8446b178-c865-4f5c-8ccc-1d7887811ae3}";
in
{
  # Browser. moonarch runs waterfox-bin, which nixpkgs does not carry; see
  # DECISIONS.md for why this is not packaged here.
  #
  # The module puts the wrapped Firefox into environment.systemPackages itself,
  # which is why the package list below names only the second browser.
  # autoConfigFiles is what carries Betterfox: the wrapper concatenates every
  # file named here into mozilla.cfg, which Firefox reads before a profile
  # exists — the only way in without home-manager.
  programs.firefox = {
    enable = true;
    languagePacks = [ "de" ];
    autoConfigFiles = [ "${moonarchPkgs.betterfox}/user.cfg" ];

    # Betterfox rewrites user_pref to defaultPref so that each of its 115 values
    # stays changeable in about:config. This option defaults to "locked", which
    # would nail these three down harder than the set they sit in.
    preferencesStatus = "default";
    preferences = {
      "general.autoScroll" = true;

      # Only the offer to translate. Translating by hand from the context menu
      # keeps working.
      "browser.translations.automaticallyPopup" = false;

      # ExtensionSettings installs the theme but does not select it; without
      # this, Firefox starts on the default look with Catppuccin sitting unused
      # in the add-on manager.
      "extensions.activeThemeID" = catppuccinThemeId;

      # The two autofill switches in the privacy settings, "Save and fill
      # addresses" and "Save and fill payment methods". Each carries a capture
      # half as a child preference, so one switch covers both storing and
      # filling. Betterfox leaves these alone; Firefox ships them on.
      "extensions.formautofill.addresses.enabled" = false;
      "extensions.formautofill.creditCards.enabled" = false;
    };

    # normal_installed rather than force_installed: both add-ons stay removable.
    # Leaving LibreWolf was about hardening that could only be undone by hand.
    #
    # The latest.xpi URLs redirect to whatever the current version is, so
    # neither add-on needs a version bump here.
    policies = {
      ExtensionSettings = {
        "uBlock0@raymondhill.net" = {
          installation_mode = "normal_installed";
          install_url = "https://addons.mozilla.org/firefox/downloads/latest/ublock-origin/latest.xpi";
        };
        ${catppuccinThemeId} = {
          installation_mode = "normal_installed";
          install_url = "https://addons.mozilla.org/firefox/downloads/latest/catppuccin-mocha-lavender-git/latest.xpi";
        };
      };

      # languagePacks installs the German pack, it does not switch to it — the
      # same split as the theme above. Firefox does not derive this from LANG
      # either: without the policy the interface stays English with the pack
      # sitting installed and active.
      RequestedLocales = [ "de" ];

      # The three suggestion switches in the search settings. Their preferences
      # ship as false and no user value sets them, so something enables them at
      # runtime — the policy is what holds against that. From Firefox 146 on,
      # WebSuggestions switches Suggest off as a whole; this is 156.
      #
      # ImproveSuggest is the data collection behind it: what gets typed into
      # the address bar goes to Mozilla to improve the suggestions. It is stated
      # rather than left to follow from the other two, so it does not come back
      # if Suggest is ever turned on again.
      FirefoxSuggest = {
        WebSuggestions = false;
        SponsoredSuggestions = false;
        ImproveSuggest = false;
      };

      SearchEngines.Default = "DuckDuckGo";
      OfferToSaveLogins = false;

      # Startup and the home button both land on a blank page. StartPage
      # "homepage" is what makes the URL apply to startup as well; "none" would
      # reach the same screen but leave the home button pointing elsewhere.
      Homepage = {
        URL = "about:blank";
        StartPage = "homepage";
      };

      # A new tab opens blank as well, rather than on the Firefox start page
      # with its search field and shortcuts.
      NewTabPage = false;

      # The initial state only — the toolbar stays something you can bring back
      # from the View menu. There is no policy that locks it away.
      DisplayBookmarksToolbar = "never";

      # This is the Sync policy. There is no DisableSync: the CCK2 name of this
      # one is disableSync, and it sets identity.fxaccounts.enabled.
      DisableFirefoxAccounts = true;

      # DisablePocket is deprecated and, by Mozilla's own note, leaves the new
      # tab page alone. FirefoxHome covers that half: Stories replaced Pocket
      # there in Firefox 141, after the service was discontinued.
      DisablePocket = true;
      FirefoxHome = {
        Stories = false;
        SponsoredStories = false;
      };
    };
  };

  # Both browsers claim x-scheme-handler/http in their desktop entries, and
  # with two candidates xdg-open picks by whatever order it finds them in.
  # These four types are exactly what firefox.desktop declares.
  xdg.mime.defaultApplications = {
    "text/html" = "firefox.desktop";
    "application/xhtml+xml" = "firefox.desktop";
    "x-scheme-handler/http" = "firefox.desktop";
    "x-scheme-handler/https" = "firefox.desktop";
  };

  environment.systemPackages = [
    # Second browser, for testing against a Blink engine. The ungoogled
    # variant because the stock chromium carries the Google endpoints; it is
    # fully substitutable, so the patch set does not have to be built here.
    # Firefox comes from programs.firefox above and is the default handler.
    pkgs.ungoogled-chromium
  ];
}