// Add event listener and log received events. It fails in both cases when I do and do not pass listener type as first arg
fdc3.addEventListener(null, console.warn);

// Join a channel
await fdc3.joinUserChannel("fdc3.channel.1");

/* The handler is invoked with:
{ 
  type: "userChannelChanged",
  details: {
    currentChannelId: "fdc3.channel.1"
  }
}
*/

// Leave the current channel
await fdc3.leaveCurrentChannel();

// The handler is invoked with:
/*
{
  type: "channelChangedEvent",
  newChannelId: null
}
*/

function wrapHandler(handler: EventHandler): (msg: AgentEventMessage) => void {
  return (m: AgentEventMessage) => {
    if (m.type !== "channelChangedEvent") {
      // Ignore unsupported event types (or throw if appropriate)
      return;
    }
    // 'currentChannelId' takes precedence over deprecated 'newChannelId' if it's set.
    const currentChannelId =
      m.payload.currentChannelId ?? m.payload.newChannelId ?? null;
    // Creating correct channel changed even which follows the typings of the standard
    const channelChangedEvent: FDC3ChannelChangedEvent = {
      type: "userChannelChanged",
      details: { currentChannelId }
    };
    handler(channelChangedEvent);
  };
}