import type {
  BaseInteraction,
  ListenerOptions,
  TransportOptions,
} from '../interface';
import { Transport } from '../transport';

const defaultChannel = '$$BroadcastChannel_Transport$$';

export interface BroadcastTransportOptions extends Partial<TransportOptions> {
  /**
   * Specify a broadcast channel name.
   */
  channel?: string;
  /**
   * Specify a broadcast channel instance.
   */
  broadcastChannel?: BroadcastChannel;
}

abstract class BroadcastTransport<
  T extends BaseInteraction = any
> extends Transport<T> {
  constructor(_options: BroadcastTransportOptions = {}) {
    const {
      channel = defaultChannel,
      broadcastChannel = new BroadcastChannel(channel),
      listener = (callback) => {
        const handler = ({ data }: MessageEvent<ListenerOptions>) => {
          callback(data);
        };
        broadcastChannel.addEventListener('message', handler);
        return () => {
          broadcastChannel.removeEventListener('message', handler);
        };
      },
      sender = (message) => broadcastChannel.postMessage(message),
      ...options
    } = _options;
    super({
      ...options,
      listener,
      sender,
    });
  }
}

export { BroadcastTransport };