import { WebClient } from '@slack/web-api';

  const client = new WebClient(token);

  async function sendStreaming(channel: string, threadTs: string, teamId: string, userId: string, 
  chunks: AsyncIterable<string>) {
    const streamer = client.chatStream({
      channel,
      thread_ts: threadTs,
      recipient_team_id: teamId,
      recipient_user_id: userId,
    });

    let fullText = '';
    let streamAlive = true;

    for await (const chunk of chunks) {
      fullText += chunk;

      if (streamAlive) {
        try {
          await streamer.append({ markdown_text: chunk });
        } catch (error) {
          if (error.data?.error === 'message_not_in_streaming_state') {
            streamAlive = false;
          } else {
            throw error;
          }
        }
      }

      if (!streamAlive) {
        await client.chat.update({ channel, ts: streamer.ts, text: fullText });
      }
    }

    if (streamAlive) {
      await streamer.stop();
    } else {
      await client.chat.update({ channel, ts: streamer.ts, text: fullText });
    }
  }