{ config, lib, ... }:
{
  options.aether = {
    inherit (import ../options.nix { inherit lib; }) domain acme acmeEmail;

    forgejo = {
      subdomain = lib.mkOption {
        type = lib.types.nullOr lib.types.str;
        default = "git";
        description = ''
          The subdomain to host the Forgejo instance under.

          If null, then Forgejo is hosted at the domain itself.
        '';
      };

      user = lib.mkOption {
        type = lib.types.str;
        default = "git";
        description = ''
          The user to run Forgejo with.
        '';
      };

      createUser = lib.mkOption {
        type = lib.types.bool;
        default = true;
        description = ''
          Whether to create the Forgejo user automatically.
        '';
      };

      templates = lib.mkOption {
        type = lib.types.nullOr lib.types.path;
        default = null;
        description = ''
          A directory of templates for customizing Forgejo's appearance.
        '';
      };
    };
  };

  config =
    let
      cfg = config.aether.forgejo;
      forgejo = config.services.forgejo;
      srv = forgejo.settings.server;
    in {
      # Web server

      services.nginx.enable = true;
      services.nginx.virtualHosts.${srv.DOMAIN} = {
        forceSSL = config.aether.https;
        enableACME = config.aether.https;
        extraConfig = ''
        client_max_body_size 512M;
      '';
        locations."/".proxyPass = "http://localhost:${builtins.toString srv.HTTP_PORT}";
      };

      security.acme.acceptTerms = config.aether.https;
      security.acme.defaults.email = cfg.acmeEmail;

      networking.firewall.allowedTCPPorts =
        [ 80 ] ++ lib.optional config.aether.https;

      # Forgejo

      services.forgejo = {
        enable = true;
        user = cfg.user;
        group = forgejo.user;
        database.user = forgejo.user;

        settings.server = {
          DOMAIN = lib.optionalString !(builtins.isNull cfg.subdomain) "${cfg.subdomain}."
                   + config.aether.domain;
          ROOT_URL = "https://${srv.DOMAIN}/";
        };
      };

      systemd.tmpfiles.rules =
        lib.optional
          !(builtins.isNull cfg.templates)
          "L+ ${cfg.stateDir}/custom/templates - - - - ${cfg.templates}";
    }
    // lib.mkIf cfg.createUser {
      users.users.${forgejo.user} = {
        home = forgejo.stateDir;
        useDefaultShell = true;
        group = forgejo.group;
        isSystemUser = true;
      };
      users.groups.${forgejo.group} = {};
    };
}