{ config, lib, pkgs, inputs, ... }@args:

let
  pkgs' = import inputs.nixpkgs {
    system = args.system;
    overlays = [ inputs.nur.overlays.default ];
  };
in {
  programs.firefox = {
    enable = true;

    # Available language codes can be found on the releases page:
    # https://releases.mozilla.org/pub/firefox/releases/134.0.2/linux-x86_64/xpi/.
    # The string `134.0.2` may be substituted for any other Firefox release
    # number.
    languagePacks = [
      "en-US"
      "en-GB"
    ];

    # Available options can be found at https://mozilla.github.io/policy-templates/.
    policies = {
      DisableTelemetry = true;
      DisableFirefoxStudies = false;
      EnableTrackingProtection = {
        Value = true;
        Locked = true;
        Cryptomining = true;
        Fingerprinting = true;
      };
      FirefoxHome = {
        Search = true;
        TopSites = true;
        SponsoredTopSites = false;
        Highlights = false;
        Pocket = false;
        SponsoredPocket = false;
        Snippets = false;
        Locked = false;
      };
      # Weird advertiser shit.
      FirefoxSuggest = {
        WebSuggestions = false;
        SponsoredSuggestions = false;
        ImproveSuggest = false;
        Locked = false;
      };
      # Weird advertiser shit.
      DisablePocket = true;
      DisableFirefoxAccounts = true;
      DisableAccounts = true;
      # Firefox has an in-built screenshot tool that I do not need.
      DisableFirefoxScreenshots = true;
      # Disable pop-up windows that appear after installation and updates.
      OverrideFirstRunPage = "";
      OverridePostUpdatePage = "";
      # You think you're so important, don't you, Firefox?
      DontCheckDefaultBrowser = true;
      # Only tabs not yet visiting a page.  Alternatives: `always`, `never`,
      # `newtab`.
      DisplayBookmarksToolbar = "newtab";
      # Alternatives: `always`, `never`, `default-on`, `default-on`.
      DisplayMenuBar = "default-off";
      # Alternative: `unified`, `separate`.
      SearchBar = "unified";
    };

    profiles."msyds" = {
      bookmarks = [];

      # Check about:support for extension/add-on ID strings.
      extensions = {
        # Override non-declared settings.
        force = true;
        packages = with pkgs'.nur.repos.rycee.firefox-addons; [
          ublock-origin
          darkreader
          privacy-badger
          vimium
          kagi-search
          duckduckgo-privacy-essentials
          edit-with-emacs
          copy-as-org-mode
          clearurls
        ];
      };

      search = {
        # Override non-declared settings.
        force = true;
        # Precedence of search engines.
        order = [ "Kagi" "DuckDuckGo" ];
        default = "Kagi";
        privateDefault = "DuckDuckGo";
        engines = {
          "Nixpkgs" = {
            urls = [{
              template = "https://search.nixos.org/packages";
              params = [
                { name = "type"; value = "packages"; }
                { name = "query"; value = "{searchTerms}"; }
              ];
            }];
            icon =
              "${pkgs.nixos-icons}/share/icons/hicolor/scalable/apps/nix-snowflake.svg";
            definedAliases = [ "!np" ];
          };
        };
      };

      # See `about:config` in Firefox for available settings.
      settings = {
        # Disable suggestions.
        "browser.search.suggest.enabled" = false;
        # Enable dark theme for non-website UI; the URL bar and such.
        "extensions.activeThemeID" = "firefox-compact-dark@mozilla.org";
        "browser.theme.content-theme" = 0;
        "browser.theme.toolbar-theme" = 0;
        "browser.in-content.dark-mode" = true;
        "ui.systemUsesDarkTheme" = 1;
        # Disable sponsored suggestions.
        "browser.newtabpage.activity-stream.showSponsoredTopSites" = false;
        "browser.newtabpage.activity-stream.system.showSponsored" = false;
        "browser.newtabpage.activity-stream.showSponsored" = false;
        "browser.urlbar.sponsoredTopSites" = false;
        "services.sync.prefs.sync.browser.newtabpage.activity-stream.showSponsored"
          = false;
        "services.sync.prefs.sync.browser.newtabpage.activity-stream.showSponsoredTopSites"
          = false;
      };
    };
  };
}