module Stream = Stream
module Sasl = Sasl
module Starttls = Starttls
module Wire = Wire
module Xml = Xml

open Lwt.Syntax
open Lwt.Infix

(** [connect domain config] is a promise containing the portal connected to the XMPP
    server located at [domain], and all its supported features.

    Basically, it conforms to {{:
    https://datatracker.ietf.org/doc/html/rfc6120#section-4.3 }}, and gets the provided
    Portal in a "ready" state. *)
let connect (domain : string) (config : Stream.config) : (Portal.t * Stream.features) Lwt.t =
  let open Portal in
  let* portal = connect domain
  in
  let needs_restart = function
    | Stream.Mechanisms _ | STARTTLS -> true
    | _ -> false
  in
  let+ features =
    let rec handle_features (features : Stream.features) : Stream.features Lwt.t =
      match features with
      | feature :: mandatory, optional ->
         let* () = Stream.negotiate true feature portal config
         in if needs_restart feature
            then Stream.start domain portal >>= handle_features
            else handle_features (mandatory, optional)
      | features -> Lwt.return features
    in Stream.start domain portal >>= handle_features
  in (portal, features)