/**
 * How long a display waits before trying a failed request again.
 *
 * Exponential from one second to a one-minute ceiling, so a screen whose server is restarting is
 * back within seconds, and one whose server is down for an evening asks once a minute rather than
 * hammering it. The wait is jittered between half and all of that step, so a building's worth of
 * screens that lost the server at the same moment do not all come back at the same moment.
 *
 * There is no attempt limit. A television on a wall has nobody to press Retry, so giving up is the
 * one thing it must never do.
 */
export const DISPLAY_RETRY_BASE_MS = 1_000;
export const DISPLAY_RETRY_MAX_MS = 60_000;

export function displayRetryDelayMs(attempt: number, random: () => number = Math.random): number {
  const step = Math.min(
    DISPLAY_RETRY_MAX_MS,
    DISPLAY_RETRY_BASE_MS * 2 ** Math.min(Math.max(0, attempt), 16),
  );
  return Math.round(step / 2 + (step / 2) * Math.min(1, Math.max(0, random())));
}