import { useCallback, useRef } from 'react';
import type { ThreadClaimState } from '../utils/messaging/threadClaim';

/** The server's claim lasts 5 minutes; renewing once a minute keeps an active claim well inside it. */
const RENEW_EVERY_MS = 60_000;

/**
 * Keeps MY claim on a pooled conversation alive while I work in it.
 *
 * The server expects this: its claim lapses after five minutes, on the understanding that "the client
 * refreshes by re-claiming while the receptionist is active". Call the returned function on activity
 * (typing, sending). It renews only a claim I already hold, so activity never takes a conversation, and
 * the server's answer, a lapse or a 409 naming a colleague included, is what the screen then shows.
 */
export const useClaimKeepAlive = ({
  claim,
  viewerAccountId,
  renew,
  onChanged,
}: {
  claim: ThreadClaimState | undefined;
  viewerAccountId: string | undefined;
  renew: (threadId: string) => Promise<ThreadClaimState>;
  onChanged: (claim: ThreadClaimState) => void;
}): (() => void) => {
  const lastRenewedAt = useRef(0);
  const heldByMe = Boolean(claim?.claimed && viewerAccountId && claim.claimedByAccountId === viewerAccountId);
  const threadId = claim?.threadId;

  return useCallback(() => {
    if (!heldByMe || !threadId) return;
    const now = Date.now();
    if (now - lastRenewedAt.current < RENEW_EVERY_MS) return;
    lastRenewedAt.current = now;

    renew(threadId)
      .then(onChanged)
      .catch(() => {
        // A failed renewal changes nothing on screen; the claim simply runs its course and the strip
        // shows it lapsing. The next activity after the throttle tries again.
      });
  }, [heldByMe, threadId, renew, onChanged]);
};