kittybox:
{ config, pkgs, lib, ... }:
with lib;
let
  cfg = config.services.kittybox;
in {
  options = {
    services.kittybox = {
      enable = mkOption {
        type = types.bool;
        default = false;
        description = ''
          Whether to enable Kittybox, the IndieWeb blogging solution.
        '';
      };
      package = mkOption {
        type = types.package;
        default = kittybox.packages.${config.nixpkgs.localSystem.system}.kittybox;
        defaultText = "<kittybox package from the upstream flake>";
        description = "Which Kittybox derivation to use.";
      };

      bind = mkOption {
        type = types.nullOr types.str;
        default = "127.0.0.1";
        description = "The host for Kittybox to bind to.";
        example = "192.168.1.100";
      };
      port = mkOption {
        type = types.int;
        default = 8080;
        description = "The port for Kittybox to listen at.";
        example = 16420;
      };
      logLevel = mkOption {
        type = types.str;
        default = "warn";
        example = "info";
        description = "Specify the server verbosity level. Uses RUST_LOG environment variable internally.";
      };
      backendUri = mkOption {
        type = types.str;
        default = "file:///var/lib/kittybox/data";
        example = "redis://192.168.1.200:6379";
        description = ''
          Set the backend used for storing data. Available backends are:
           - file:// - static folder backend (recommended)
           - redis:// - Redis backend (currently unavailable)

          Make sure that if you are using the file backend, the state
          directory is accessible by Kittybox. By default, the unit config
          uses DynamicUser=true, which prevents the unit from accessing
          data outside of its directory. It is recommended to use a
          bind-mount to /var/lib/private/kittybox if you require the state
          directory to reside elsewhere.
        '';
      };
      blobstoreUri = mkOption {
        type = types.nullOr types.str;
        default = "file:///var/lib/kittybox/media";
        description = ''
          Set the backend used for the media endpoint storage. Available options are:
            - file:// - content-addressed storage using flat files (recommended)

          When using the file backend, check notes in the `backendUri` option too.
        '';
      };
      microsubServer = mkOption {
        type = types.nullOr types.str;
        default = null;
        example = "https://aperture.p3k.io/microsub/69420";
        description = ''
          The URL of your Microsub server, which saves feeds for you
          and allows you to browse Web content from one place. Try
          https://aperture.p3k.io/ if you don't have one yet!
        '';
      };
      webmentionEndpoint = mkOption {
        type = types.nullOr types.str;
        default = null;
        example = "https://webmention.io/example.com/webmention";
        description = ''
          The URL of your webmention endpoint, which allows you to
          receive notifications about your site's content being featured
          or interacted with elsewhere on the IndieWeb.

          By default Kittybox expects the Webmention endpoint to post
          updates using an internal token. kittybox-webmention is an
          endpoint capable of that.
        '';
      };
      internalTokenFile = mkOption {
        type = types.nullOr types.str;
        default = null;
        example = "/run/secrets/kittybox-shared-secret";
        description = "A shared secret that will, when passed, allow unlimited editing access to database. Keep it safe.";
      };
      cookieSecretFile = mkOption {
        type = types.str;
        default = "/var/lib/kittybox/cookie_secret_key";
        example = "/run/secrets/kittybox-cookie-secret";
        description = "A secret file to encrypt cookies with the contents of. Should be at least 32 bytes in length. A random persistent file will be generated if this variable is left untouched.";
      };
    };
  };
  config = lib.mkIf cfg.enable {
    systemd.services.kittybox = {
      description = "An IndieWeb-enabled blog engine";

      wantedBy = [ "multi-user.target" ];
      after = [ "network.target" ];

      restartTriggers = [
        cfg.package
        cfg.backendUri cfg.blobstoreUri
        cfg.internalTokenFile
        cfg.bind cfg.port
        cfg.cookieSecretFile
      ];

      environment = {
        SERVE_AT = "${cfg.bind}:${builtins.toString cfg.port}";
        MICROSUB_ENDPOINT = cfg.microsubServer;
        WEBMENTION_ENDPOINT = cfg.webmentionEndpoint;
        #REDIS_URI = if (cfg.redisUri == null) then "redis://127.0.0.1:6379/" else cfg.redisUri;
        BACKEND_URI = cfg.backendUri;
        BLOBSTORE_URI = cfg.blobstoreUri;
        RUST_LOG = "${cfg.logLevel}";
        COOKIE_SECRET_FILE = "${cfg.cookieSecretFile}";
      };

      script = ''
        ${lib.optionalString (cfg.internalTokenFile != null) ''
          if [[ -f ${cfg.internalTokenFile} ]]; then
            export KITTYBOX_INTERNAL_TOKEN=$(${pkgs.coreutils}/bin/cat ${cfg.internalTokenFile})
          fi
        ''}
        if [[ ${cfg.cookieSecretFile} == /var/lib/kittybox/cookie_secret_key && ! -f /var/lib/kittybox/cookie_secret_key ]]; then
            cat /dev/urandom | tr -Cd '[:alnum:]' | head -c 128 > /var/lib/kittybox/cookie_secret_key
        fi
        exec ${cfg.package}/bin/kittybox
      '';

      serviceConfig = {
        DynamicUser = true;
        StateDirectory = "kittybox";
      };
    };
  };
}