{ lib, lispPackages, openssl_1_1, sbcl, writeShellApplication, cl-gemini, ... }:

with lib;
let
  serverLauncher = pkgs.writeText "launch-cl-gemini.lisp" ''
    (defun getenv-or-fail (env-var &optional default)
      (let ((value (uiop:getenv env-var)))
        (if (null value)
            (if default
                default
                (uiop:die 1 "unable to find required env var: ~A" env-var))
            value)))

    (require :asdf)
    (asdf:load-system :slynk)
    (asdf:load-system :cl-gemini)
    (let ((slynk-port (uiop:getenvp "GEMINI_SLYNK_PORT")))
      (when slynk-port
        (slynk:create-server :port (parse-integer slynk-port) :dont-close t)))
    (let ((feed-file (uiop:getenvp "GEMINI_FEEDS")))
      (when feed-file
        (load feed-file)))
    (cl-gemini:start-gemini-server
      (getenv-or-fail "GEMINI_LISTEN_IP")
      (getenv-or-fail "GEMINI_PRIVATE_KEY")
      (getenv-or-fail "GEMINI_CERTIFICATE")
      :port (parse-integer (getenv-or-fail "GEMINI_LISTEN_PORT"))
      :document-root (getenv-or-fail "GEMINI_DOCUMENT_ROOT")
      :textfiles-root (getenv-or-fail "GEMINI_TEXTFILES_ROOT")
      :log-stream *standard-output*
      :threaded t
      :separate-thread t)
    (loop (sleep 10))
  '';

  sbcl-with-ssl = sbcl.overrideAttrs (oldAttrs: rec {
    propagatedBuildInputs = oldAttrs.buildInputs ++ [ openssl_1_1.dev ];
  });

in writeShellApplication {
  name = "cl-gemini-launcher";

  runtimeInputs = [ asdf sbcl-with-ssl openssl_1_1 cl-gemini ];

  text =
    "${lispPackages.clwrapper}/bin/common-lisp.sh --load ${server-launcher}";
}