import { MatrixClient } from 'matrix-js-sdk';
import { AccountDataEvent } from '../../types/matrix/accountData';
import { getAccountData } from './room';

/**
 * [Gitea #300] The status message's auto-clear time, in account data so every
 * Lotus device knows it. Before, only the device that set "clear after 1 hour"
 * (localStorage) ever cleared it, and only while it was open.
 */
export type StatusExpiry = { statusMsg: string; expiresAt: number };

/** Pure: parse `io.lotus.status_expiry` content. */
export function parseStatusExpiry(content: unknown): StatusExpiry | undefined {
  const c = content as { status_msg?: unknown; expires_at?: unknown } | undefined;
  if (!c || typeof c.status_msg !== 'string' || typeof c.expires_at !== 'number') return undefined;
  if (!c.status_msg || !Number.isFinite(c.expires_at)) return undefined;
  return { statusMsg: c.status_msg, expiresAt: c.expires_at };
}

/**
 * Pure: what to do with a due expiry. Clear the server status only if it is
 * still the one that was set to expire; if it has since changed (e.g. on
 * another device), just forget the expiry.
 */
export function statusExpiryAction(
  entry: StatusExpiry | undefined,
  currentStatusMsg: string | undefined,
  now: number,
): 'none' | 'clear' | 'forget' {
  if (!entry || now < entry.expiresAt) return 'none';
  return (currentStatusMsg ?? '') === entry.statusMsg ? 'clear' : 'forget';
}

export const readStatusExpiry = (mx: MatrixClient): StatusExpiry | undefined =>
  parseStatusExpiry(getAccountData(mx, AccountDataEvent.LotusStatusExpiry)?.getContent());

/** Record (or with no `expiresAt`, remove) the shared auto-clear time. */
export async function writeStatusExpiry(
  mx: MatrixClient,
  statusMsg: string,
  expiresAt?: number,
): Promise<void> {
  const content =
    statusMsg && expiresAt !== undefined ? { status_msg: statusMsg, expires_at: expiresAt } : {};
  await mx.setAccountData(AccountDataEvent.LotusStatusExpiry as never, content as never);
}