/**
 * Single source of truth for how long a PENDING_PAYMENT booking has to be paid for,
 * shared by TasksService (which auto-cancels bookings past this deadline) and
 * SeatsService (which extends the seat hold to cover exactly this window when a
 * booking/PNR is created — without this, the seat hold reverted to its original
 * short seat-selection TTL and could expire mid-payment, letting a second customer
 * grab the same seat).
 */

/** Maximum time (hours) a passenger has to pay after booking. */
export const MAX_PAYMENT_HOURS = 2;
/** Minutes before departure: cutoff for new bookings and payment deadline. */
export const CUTOFF_MINUTES = 30;

/**
 * How long a passenger is given to finish one provider payment session, once opened.
 * 5 minutes of actual paying (redirect → PIN/OTP → provider callback) + 1 minute of slack.
 */
export const PAYMENT_SESSION_MINUTES = 6;


export const MIN_PAYMENT_WINDOW_MINUTES = 7;

export const PAYMENT_SETTLE_MARGIN_SECONDS = 60;


export function computePaymentDeadline(
  createdAt: Date,
  departureAt: Date,
  checkinMinutes: number = CUTOFF_MINUTES,
): Date {
  const maxDeadline    = new Date(createdAt.getTime() + MAX_PAYMENT_HOURS * 60 * 60 * 1000);
  const cutoffDeadline = new Date(departureAt.getTime() - checkinMinutes * 60 * 1000);
  return maxDeadline < cutoffDeadline ? maxDeadline : cutoffDeadline;
}


export function canOpenPaymentSession(
  paymentDeadline: Date,
  now: Date = new Date(),
): boolean {
  return paymentDeadline.getTime() - now.getTime() >= MIN_PAYMENT_WINDOW_MINUTES * 60 * 1000;
}

export function computePaymentSessionExpiry(
  paymentDeadline: Date,
  now: Date = new Date(),
): Date {
  const sessionEnd = new Date(now.getTime() + PAYMENT_SESSION_MINUTES * 60 * 1000);
  return sessionEnd < paymentDeadline ? sessionEnd : paymentDeadline;
}