{ pkgs, ... }:
  let
    lock-false = {
      Value = false;
      Status = "locked";
    };
    lock-true = {
      Value = true;
      Status = "locked";
    };
  in
{
  programs.firefox = {
    enable = true;
    package = pkgs.firefox.override {
      extraPrefs = ''
        //

        // Automatically click cookiebanners although uBlock Origin might block them
        lockPref("cookiebanners.bannerClicking.enabled", true);
        lockPref("cookiebanners.service.mode", 2);
        lockPref("cookiebanners.service.mode.privateBrowsing", 2);

        // DNT although PrivacyBadger from policy handles this
        lockPref("privacy.donottrackheader.enabled", true);
        lockPref("privacy.donottrackheader.value", 1);

        // Fingerprinting
        lockPref("privacy.fingerprintingProtection", true);
        pref(
        	"privacy.fingerprintingProtection.overrides",
        	"+AllTargets,-KeyboardEvents,-SpeechSynthesis,-CSSPrefersColorScheme,-CSSPrefersReducedMotion,-NavigatorUserAgent,-JSDateTimeUTC,-HttpUserAgent",
        );
        lockPref("privacy.fingerprintingProtection.pbmode", true);
        lockPref("privacy.resistFingerprinting", false);
        lockPref("privacy.resistFingerprinting.block_mozAddonManage", true);
        lockPref("privacy.resistFingerprinting.letterboxing", false);
        clearPref("privacy.resistFingerprinting.pbmode");

        // New sidebar
        lockPref("sidebar.revamp", true);
        lockPref("sidebar.verticalTabs", true);
        lockPref("sidebar.visibility", "always-show");
        lockPref("sidebar.main.tools", "");

        //
      '';
    };

    policies = {
      EnableTrackingProtection = {
        Value = true;
        Locked = true;
        Cryptomining = true;
        Fingerprinting = true;
        EmailTracking = true;
      };

      # Certificates
      Certificates = {
        ImportEnterpriseRoots = true;
        Install = [
          "freya_ca.crt"
          "tinternet.crt"
        ];
      };

      # Cookies
      Cookies = {
        Behavior = "reject-foreign";
        BehaviorPrivateBrowsing = "reject-foreign";
        Locked = true;
      };

      # DNS
      DNSOverHTTPS = {
        Enabled = false;
        Locked = true;
      };

      # Disable Bad
      DisableAppUpdate = true;
      DisableAccounts = true;
      DisableFirefoxAccounts = true;
      DisableFirefoxScreenshots = true;
      DisableFirefoxStudies = true;
      DisablePocket = true;
      DisableTelemetry = true;
      AutofillAddressEnabled = false;
      AutofillCreditCardEnabled = false;

      # Disable Certain Messages
      UserMessaging = {
        WhatsNew = false;
        ExtensionRecommendations = false;
        FeatureRecommendations = false;
        UrlbarInterventions = false;
        SkipOnboarding = true;
        MoreFromMozilla = false;
        Labs = false;
        Locked = true;
      };

      # Disable Password Manager
      DisableMasterPasswordCreation = true;
      PasswordManagerEnabled = false;
      PrimaryPassword = false;
      OfferToSaveLogins = false;

      # Remove Special Pages
      OverrideFirstRunPage = "";
      OverridePostUpdatePage = "";

      # Start Page
      Homepage = {
        StartPage = "previous-session";
        Locked = true;
      };

      # Home Page
      FirefoxHome = {
        Search = true;
        TopSites = false;
        SponsoredTopSites = false;
        Highlights = false;
        Pocket = false;
        SponsoredPocket = false;
        Snippets = false;
        Locked = true;
      };

      # Search Suggestions
      SearchSuggestEnabled = true;
      FirefoxSuggest = {
        WebSuggestions = false;
        SponsoredSuggestions = false;
        ImproveSuggest = false;
        Locked = true;
      };

      # Save All on Shutdown
      SanitizeOnShutdown = {
        Cache = false;
        Cookies = false;
        Downloads = false;
        Histroy = false;
        Sessions = false;
        SiteSettings = false;
        OfflineApps = false;
        Locked = true;
      };

      # Popups
      PopupBlocking = {
        Default = true;
        Locked = true;
      };

      # Allow Bypasses
      DisableSecurityBypass = {
        InvalidCertificate = false;
        SafeBrowsing = false;
      };

      # PictureInPicure
      PictureInPicture = {
        Enabled = true;
        Locked = true;
      };

      # Topbar
      SearchBar = "unified";
      DisplayMenuBar = "default-off";
      DisplayBookmarksToolbar = "newtab";
      NoDefaultBookmarks = true;

      # Miscellaneous
      HttpsOnlyMode = "force_enabled";
      HardwareAcceleration = true;
      DontCheckDefaultBrowser = true;
      PromptForDownloadLocation = false;
      PrivateBrowsingModeAvailability = 0;

      # Extensions
      ExtensionSettings = {
        "*".installation_mode = "blocked";
        # uBlock Origin
        "uBlock0@raymondhill.net" = {
          install_url = "https://addons.mozilla.org/firefox/downloads/latest/ublock-origin/latest.xpi";
          installation_mode = "force_installed";
        };
        # Bitwarden
        "{446900e4-71c2-419f-a6a7-df9c091e268b}" = {
          install_url = "https://addons.mozilla.org/firefox/downloads/latest/bitwarden-password-manager/latest.xpi";
          installation_mode = "force_installed";
        };
        # User Agent Switcher
        "user-agent-switcher@ninetailed.ninja" = {
          install_url = "https://addons.mozilla.org/firefox/downloads/latest/uaswitcher/latest.xpi";
          installation_mode = "force_installed";
        };
        # SponsorBlock
        "sponsorBlocker@ajay.app" = {
          install_url = "https://addons.mozilla.org/firefox/downloads/latest/sponsorblock/latest.xpi";
          installation_mode = "force_installed";
        };
        # Privacy Badger
        "jid1-MnnxcxisBPnSXQ@jetpack" = {
          install_url = "https://addons.mozilla.org/firefox/downloads/latest/privacy-badger17/latest.xpi";
          installation_mode = "force_installed";
        };
        # FoxyProxy
        "foxyproxy@eric.h.jung" = {
          install_url = "https://addons.mozilla.org/firefox/downloads/latest/foxyproxy-standard/latest.xpi";
          installation_mode = "force_installed";
        };
      };

      # about:config Preferences
      Preferences = {
        # theme
        "toolkit.legacyUserProfileCustomizations.stylesheets" = lock-true;
        "extensions.activeThemeID" = {
          Value = "firefox-compact-dark@mozilla.org";
          Status = "locked";
        };
        "layout.css.prefers-color-scheme.content-override" = {
          Value = 0;
          Status = "locked";
        };
        # homepage
        "browser.startup.homepage" = {
          Value = "	about:home";
          Status = "locked";
        };
        "browser.newtabpage.enabed" = lock-true;
        "browser.newtabpage.url" = {
          Value = "	about:home";
          Status = "locked";
        };
        # autofill
        "browser.autofill.enabled" = lock-false;
        "browser.formfill.enable" = lock-false;
        # search enable
        "browser.urlbar.suggest.recentsearches" = lock-true;
        "browser.urlbar.suggest.bookmark" = lock-true;
        "browser.urlbar.suggest.clipboard" = lock-true;
        "browser.urlbar.suggest.history" = lock-true;
        # search disable
        "browser.urlbar.suggest.addons" = lock-false;
        "browser.urlbar.suggest.calculator" = lock-false;
        "browser.urlbar.suggest.engines" = lock-false;
        "browser.urlbar.suggest.fakespot" = lock-false;
        "browser.urlbar.suggest.mdn" = lock-false;
        "browser.urlbar.suggest.openpage" = lock-false;
        "browser.urlbar.suggest.pocket" = lock-false;
        "browser.urlbar.suggest.remotetab" = lock-false;
        "browser.urlbar.suggest.topsites" = lock-false;
        "browser.urlbar.suggest.trending" = lock-false;
        "browser.urlbar.suggest.weather" = lock-false;
        "browser.urlbar.suggest.yelp" = lock-false;
        # privacy
        "privacy.globalprivacycontrol.enabled" = lock-true;
        # security
        "security.OCSP.enabled" = {
          Value = 0;
          Status = "locked";
        };
        "browser.contentblocking.category" = {
          Value = "strict";
          Status = "locked";
        };
        "xpinstall.whitelist.required" = lock-true;
        "signon.management.page.breach-alerts.enabled" = lock-false;
        # graphics
        "dom.webgpu.enabled" = lock-true;
        "media.eme.enabled" = lock-true;
        # user messaging
        "browser.newtabpage.activity-stream.feeds.section.topstories" = lock-false;
        "browser.newtabpage.activity-stream.feeds.snippets" = lock-false;
        "browser.newtabpage.activity-stream.section.highlights.includePocket" = lock-false;
        "browser.newtabpage.activity-stream.section.highlights.includeBookmarks" = lock-false;
        "browser.newtabpage.activity-stream.section.highlights.includeDownloads" = lock-false;
        "browser.newtabpage.activity-stream.section.highlights.includeVisited" = lock-false;
        "browser.newtabpage.activity-stream.showSponsored" = lock-false;
        "browser.newtabpage.activity-stream.system.showSponsored" = lock-false;
        "browser.newtabpage.activity-stream.showSponsoredTopSites" = lock-false;
        "browser.newtabpage.activity-stream.showWeather" = lock-false;
        "browser.newtabpage.activity-stream.newtabWallpapers.enabled" = lock-false;
        "browser.newtabpage.activity-stream.newtabWallpapers.v2.enabled" = lock-false;
        "browser.newtabpage.activity-stream.default.sites" = {
          Value = "";
          Status = "locked";
        };
        # safebrowsing
        "browser.safebrowsing.malware.enabled" = lock-true;
        "browser.safebrowsing.phishing.enabled" = lock-true;
        "browser.safebrowsing.downloads.enabled" = lock-true;
        "browser.safebrowsing.downloads.remote.block_uncommon" = lock-false;
        "browser.safebrowsing.downloads.remote.block_potentially_unwanted" = lock-false;
        # sidebar
        "browser.tabs.inTitlebar" = {
          Value = 0;
          Status = "locked";
        };
        "browser.tabs.warnOnClose" = lock-true;
        "browser.tabs.firefox-view" = lock-false;
        "browser.tabs.closeTabByDblclick" = lock-true;
        "ui.key.menuAccessKeyFocuses" = lock-false;
        # general settings
        "general.autoScroll" = lock-false;
        "general.smoothScroll" = lock-true;
        "widget.gtk.overlay-scrollbars.enabled" = lock-false;
        "accessibility.browsewithcaret" = lock-false;
        "accessibility.typeaheadfind" = lock-false;
        "media.hardwaremediakeys.enabled" = lock-true;
        "browser.crashReports.unsubmittedCheck.autoSubmit2" = lock-false;
        "browser.aboutConfig.showWarning" = lock-false;
      };
    };

    profiles = {
      "freya" = {
        search = {
          force = true;
          default = "DuckDuckGo";
          engines = {
            "Google".metaData.hidden = true;
            "Bing".metaData.hidden = true;
            "Amazon.com".metaData.hidden = true;
            "eBay".metaData.hidden = true;
            "Twitter".metaData.hidden = true;
          };
        };
        userChrome = ''
          #sidebar-header { display:none !important; }
          #sidebar-search-container { display:none !important; }
          #firefox-view-button {
            visibility: collapse;
          }
          #alltabs-button {
            visibility: collapse;
          }
          #tabbrowser-tabs {
            border-inline-start: none !important;
          }
        '';
      };
    };
  };
}