disclaw/src/discord/send-response.ts

import { TextChannel, Message, AttachmentBuilder } from "discord.js";
import { splitForDiscord } from "./split.js";
import { childLogger } from "../runtime/logger.js";

const log = childLogger("send-response");

const FILE_THRESHOLD = 4000;

/**
 * Sends an agent response to a Discord channel.
 * - Text > 4000 chars is sent as a Markdown file attachment.
 * - Text <= 4000 chars is split with splitForDiscord and sent as plain messages.
 */
export async function sendResponse(
  channel: TextChannel,
  text: string,
  _triggerMessage: Message
): Promise<void> {
  if (text.length === 0) {
    return;
  }

  if (text.length > FILE_THRESHOLD) {
    log.debug({ length: text.length }, "Response exceeds threshold — sending as file");
    await channel.send({
      files: [
        new AttachmentBuilder(Buffer.from(text, "utf-8"), {
          name: "response.md",
        }),
      ],
    });
    return;
  }

  const chunks = splitForDiscord(text);
  for (const chunk of chunks) {
    await channel.send(chunk);
  }
}