import { NoyaManager } from "../NoyaManager";
import { ParentToEmbeddedMessage } from "./parentFrameMessages";
import { ConnectionMessage } from "./types";

/**
 * Subscribe to parent-side connection events and forward child-facing messages.
 * - stateChange → { type: "connection", state: "connected" | "disconnected" }
 * - receive → forwards the original server message to the child
 */
export function forwardConnectionEventsToChild<
  S,
  M extends object,
  E extends object,
  MenuT extends string,
  I extends Record<string, any> = Record<string, unknown>,
>(
  noyaManager: NoyaManager<S, M, E, MenuT, I>,
  send: (message: ParentToEmbeddedMessage<S>) => void
) {
  return noyaManager.connectionEventManager.events$.subscribe((events) => {
    if (events.length === 0) return;
    const last = events[events.length - 1]!;
    switch (last.type) {
      case "stateChange": {
        const connectionMessage: ConnectionMessage = {
          type: "connection",
          state: last.state === "OPEN" ? "connected" : "disconnected",
        };
        send(connectionMessage);
        break;
      }
      case "receive": {
        const msg = last.message;

        // Suppress sending null document objects to the child. In embedded
        // mode, a null object is not useful and can clobber the child's own
        // initial state derived from URL params. Later non-null objects will
        // still be forwarded normally.
        if (msg && msg.type === "object" && msg.object === null) {
          break;
        }

        send(msg);
        break;
      }
    }
  });
}