cinny/src/app/utils/scheduledMessages.ts

import { IContent, MatrixClient, Method } from 'matrix-js-sdk';

/**
 * Schedule a message via MSC4140 (delayed messages).
 * Synapse implementation: pass org.matrix.msc4140.delay on the standard
 * /v3/rooms send endpoint. The server stores the event and returns delay_id
 * instead of event_id.
 */
export async function scheduleMessage(
  mx: MatrixClient,
  roomId: string,
  content: IContent,
  sendAtMs: number,
): Promise<string> {
  const delayMs = Math.max(1000, Math.round(sendAtMs - Date.now()));
  const txnId = `sched_${Date.now()}_${Math.random().toString(36).slice(2)}`;
  const path = `/rooms/${encodeURIComponent(roomId)}/send/m.room.message/${txnId}`;
  // Use standard v3 prefix with the MSC4140 delay query param.
  const res = (await mx.http.authedRequest(
    Method.Put,
    path,
    {
      'org.matrix.msc4140.delay': delayMs,
    },
    content,
  )) as { delay_id: string };
  return res.delay_id;
}

/**
 * Cancel a scheduled message via MSC4140.
 */
export async function cancelScheduledMessage(mx: MatrixClient, delayId: string): Promise<void> {
  const path = `/delayed_events/${encodeURIComponent(delayId)}`;
  await mx.http.authedRequest(
    Method.Post,
    path,
    undefined,
    { action: 'cancel' },
    { prefix: '/_matrix/client/unstable/org.matrix.msc4140' },
  );
}

export async function restartScheduledMessage(mx: MatrixClient, delayId: string): Promise<void> {
  const path = `/delayed_events/${encodeURIComponent(delayId)}`;
  await mx.http.authedRequest(
    Method.Post,
    path,
    undefined,
    { action: 'restart' },
    { prefix: '/_matrix/client/unstable/org.matrix.msc4140' },
  );
}