{
  lib,
  pkgs,
  config,
  ...
}:
with lib;
let
  cfg = config.programs.firefox;
in
{
  options.programs.firefox.forcePrivateBrowsing = mkOption {
    type = lib.types.bool;
    default = true;
    example = true;
    description = "Whether to force private browsing.";
  };

  config = {
    programs.firefox = {
      enable = true;
      languagePacks = [
        "en-US"
        "de"
      ];

      # ---- POLICIES ----
      # Check about:policies#documentation for options.
      policies = {
        Authentication = {
          "SPNEGO" = [
            "upb.de"
            "uni-paderborn.de"
            "cs.uni-paderborn.de"
          ];
          "NTLM" = [
            "upb.de"
            "uni-paderborn.de"
            "cs.uni-paderborn.de"
          ];
        };
        BlockAboutAddons = false;
        BlockAboutConfig = false;
        BlockAboutProfiles = false;
        DisableTelemetry = true;
        DisableFirefoxStudies = true;
        EnableTrackingProtection = {
          Value = true;
          Locked = true;
          Cryptomining = true;
          Fingerprinting = true;
        };
        DisablePocket = true;
        DisableFirefoxAccounts = true;
        DisableAccounts = true;
        DisableFirefoxScreenshots = true;
        OverrideFirstRunPage = "";
        OverridePostUpdatePage = "";
        AppAutoUpdate = false;
        DontCheckDefaultBrowser = true;
        PrimaryPassword = false;
        OfferToSaveLoginsDefault = false;
        PasswordManagerEnabled = false;
        DisableMasterPasswordCreation = true;
        AutofillAddressEnabled = false;
        HttpsOnlyMode = "force_enabled";
        AutofillCreditCardEnabled = false;
        DisplayBookmarksToolbar = "never"; # alternatives: "always" or "newtab"
        DisplayMenuBar = "never"; # alternatives: "always", "never" or "default-on"
        NoDefaultBookmarks = true;
        SearchSuggestEnabled = false;
        PrivateBrowsingModeAvailability = if cfg.forcePrivateBrowsing then 2 else 0;
        FirefoxHome = {
          Search = true;
          TopSites = false;
          SponsoredTopSites = false;
          Highlights = false;
          Pocket = false;
          SponsoredPocket = false;
          Snippets = false;
          Locked = false;
        };
        PopupBlocking = {
          Allow = [
            "https://vault.cs.uni-paderborn.de:8200"
            "https://vault.prod.cs.uni-paderborn.de:8200"
            "https://vault.staging.cs.uni-paderborn.de:8200"
            "https://vault.dev.cs.uni-paderborn.de:8200"
            "https://tickets.cs.uni-paderborn.de"
            "https://tickets-dev.cs.uni-paderborn.de"
          ];
        };
        SearchBar = "unified"; # alternative: "separate"
        ExtensionSettings = {
          "*" = {
            installation_mode = "blocked";
            blocked_install_message = "Addons have to be configured through home-manager!";
            allowed_types = [ ];
          };
          # Bitwarden 
          "{446900e4-71c2-419f-a6a7-df9c091e268b}" = {
            install_url = "https://addons.mozilla.org/firefox/downloads/latest/{446900e4-71c2-419f-a6a7-df9c091e268b}/latest.xpi";
            installation_mode = "normal_installed";
          };
          # Dark Reader
          "addon@darkreader.org" = {
            install_url = "https://addons.mozilla.org/firefox/downloads/latest/addon@darkreader.org/latest.xpi";
            installation_mode = "normal_installed";
          };
          # Catppuccin Mocha Blue
          "{2adf0361-e6d8-4b74-b3bc-3f450e8ebb69}" = {
            install_url = "https://addons.mozilla.org/firefox/downloads/latest/{2adf0361-e6d8-4b74-b3bc-3f450e8ebb69}/latest.xpi";
            installation_mode = "normal_installed";
          };
          # uBlock Origin
          "uBlock0@raymondhill.net" = {
            install_url = "https://addons.mozilla.org/firefox/downloads/latest/ublock-origin/latest.xpi";
            installation_mode = "normal_installed";
          };
          # LanguageTool
          "languagetool-webextension@languagetool.org" = {
            install_url = "https://addons.mozilla.org/firefox/downloads/latest/languagetool-webextension@languagetool.org/latest.xpi";
            installation_mode = "normal_installed";
          };
          # Privacy Badger
          "jid1-MnnxcxisBPnSXQ@jetpack" = {
            install_url = "https://addons.mozilla.org/firefox/downloads/latest/jid1-MnnxcxisBPnSXQ@jetpack/latest.xpi";
            installation_mode = "normal_installed";
          };
          # Tree Style Tab
          "treestyletab@piro.sakura.ne.jp" = {
            install_url = "https://addons.mozilla.org/firefox/downloads/latest/treestyletab@piro.sakura.ne.jp/latest.xpi";
            installation_mode = "normal_installed";
          };
          # Windscribe
          "@windscribeff" = {
            install_url = "https://addons.mozilla.org/firefox/downloads/latest/@windscribeff/latest.xpi";
            installation_mode = "normal_installed";
          };
        };
      };

      # ---- PREFERENCES ----
      # Check about:config for options.
      #preferencesStatus = "locked"; # locks all settings
      profiles.default = {
        containersForce = true;
        isDefault = true;
        settings = {
          "browser.contentblocking.category" = "strict";
          "extensions.pocket.enabled" = false;
          "extensions.screenshots.disabled" = true;
          "browser.topsites.contile.enabled" = false;
          "browser.formfill.enable" = false;
          "browser.search.suggest.enabled" = false;
          "browser.search.suggest.enabled.private" = false;
          "browser.urlbar.suggest.searches" = false;
          "browser.urlbar.showSearchSuggestionsFirst" = false;
          "browser.newtabpage.activity-stream.feeds.section.topstories" = false;
          "browser.newtabpage.activity-stream.feeds.snippets" = false;
          "browser.newtabpage.activity-stream.section.highlights.includePocket" = false;
          "browser.newtabpage.activity-stream.section.highlights.includeBookmarks" = false;
          "browser.newtabpage.activity-stream.section.highlights.includeDownloads" = false;
          "browser.newtabpage.activity-stream.section.highlights.includeVisited" = false;
          "browser.newtabpage.activity-stream.showSponsored" = false;
          "browser.newtabpage.activity-stream.system.showSponsored" = false;
          "browser.newtabpage.activity-stream.showSponsoredTopSites" = false;
          "extensions.autoDisableScopes" = 0;
          "browser.translations.neverTranslateLanguages" = "de";
          "browser.translations.alwaysTranslateLanguages" = "";
          "browser.warnOnQuit" = false;
          "toolkit.legacyUserProfileCustomizations.stylesheets" = true;
          "dom.security.https_only_mode" = true;
          "browser.privatebrowsing.autostart" = cfg.forcePrivateBrowsing;
          "extensions.activeThemeID" = "{2adf0361-e6d8-4b74-b3bc-3f450e8ebb69}";
          "browser.sessionstore.resume_session_once" = !cfg.forcePrivateBrowsing;
        };

        search = {
          force = true;
          default = "DuckDuckGo";
          engines = {
            "Nix Packages" = {
              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" ];
            };

            "NixOS Wiki" = {
              urls = [ { template = "https://wiki.nixos.org/index.php?search={searchTerms}"; } ];
              iconUpdateURL = "https://wiki.nixos.org/favicon.ico";
              updateInterval = 24 * 60 * 60 * 1000; # every day
              definedAliases = [ ":nw" ];
            };

            "ArchWiki" = {
              urls = [ { template = "https://wiki.archlinux.org/index.php?search={searchTerms}"; } ];
              iconUpdateURL = "https://wiki.archlinux.org/favicon.ico";
              updateInterval = 24 * 60 * 60 * 1000; # every day
              definedAliases = [ ":aw" ];
            };

            "Ecosia" = {
              urls = [ { template = "https://www.ecosia.org/search?q={searchTerms}"; } ];
              iconUpdateURL = "https://ecosia.org/favicon.ico";
              updateInterval = 24 * 60 * 60 * 1000; # every day
              definedAliases = [ "@eco" ];
            };

            "Wikipedia (de)" = {
              urls = [ { template = "https://de.wikipedia.org/w/index.php?search={searchTerms}"; } ];
              iconUpdateURL = "https://wikipedia.org/favicon.ico";
              updateInterval = 24 * 60 * 60 * 1000; # every day
              definedAliases = [ ":wd" ];
            };

            "IMDb" = {
              urls = [ { template = "https://www.imdb.com/find/?q={searchTerms}"; } ];
              iconUpdateURL = "https://imdb.com/favicon.ico";
              updateInterval = 24 * 60 * 60 * 1000; # every day
              definedAliases = [ ":f" ];
            };

            "YouTube" = {
              urls = [ { template = "https://www.youtube.com/results?search_query={searchTerms}"; } ];
              iconUpdateURL = "https://youtube.com/favicon.ico";
              updateInterval = 24 * 60 * 60 * 1000; # every day
              definedAliases = [ ":y" ];
            };

            "dict.cc (de<->en)" = {
              urls = [ { template = "https://www.dict.cc/?s={searchTerms}"; } ];
              iconUpdateURL = "https://dict.cc/favicon.ico";
              updateInterval = 24 * 60 * 60 * 1000; # every day
              definedAliases = [ ":d" ];
            };

            "MyNixOS" = {
              urls = [ { template = "https://mynixos.com/search?q={searchTerms}"; } ];
              iconUpdateURL = "https://mynixos.com/favicon.ico";
              updateInterval = 24 * 60 * 60 * 1000; # every day
              definedAliases = [ ":mn" ];
            };

            "Bing".metaData.hidden = true;
            "Google".metaData.hidden = true;
            "DuckDuckGo".metaData.alias = "@ddg"; # builtin engines only support specifying one additional alias
            "Wikipedia (en)".metaData.alias = ":w"; # builtin engines only support specifying one additional alias
          };

          order = [
            "DuckDuckGo"
            "Nix Packages"
            "ArchWiki"
            "Nix Wiki"
            "Ecosia"
          ];
        };

        bookmarks = [

        ];

        userChrome = ''
          /*** Remove items from image context menu ***/

          /* Email Image... */
          #context-sendimage, 

          /* Set Image as Desktop Background... (and preceding separator) */
          #context-sep-setbackground, #context-setDesktopBackground,

          /* Inspect Accessibility Properties */
          #context-inspect-a11y { display: none !important; }

          /* Disable Firefox View */
          #firefox-view-button { display: none !important; }

          /* Disable Tab Bar ('cause TST) */
          #TabsToolbar { visibility: collapse !important; }

          /* Remove flexible spaces
          #customizableui-special-spring1 { display: none !important; }
          #customizableui-special-spring2 { display: none !important; }
          #customizableui-special-spring3 { display: none !important; }
          #customizableui-special-spring4 { display: none !important; }
        '';
      };
    };
  };
}