Get paywall trial info (paywall.getTrialInfo)

/**
 * Represents a time-based trial information
 */
interface TimeBasedTrial {
  /** Timestamp when trial period started (in milliseconds) */
  expirationStart: number;
  /** Timestamp when trial period ends (in milliseconds) */
  expirationEnd: number;
  /** Total duration of trial period (in milliseconds) */
  expirationTime: number;
  /** Whether the trial period has expired */
  expired: boolean;
}

/**
 * Represents an opens/actions-based trial information
 */
interface OpensBasedTrial {
  /** Number of remaining trial actions available */
  remainingActions: number;
  /** Total number of actions allowed in trial */
  totalActions: number;
  /** Whether all trial actions have been used */
  expired: boolean;
}

/** All possible trial information types */
type TrialInfo = TimeBasedTrial | OpensBasedTrial | 'no trial';

interface Paywall {
  /**
   * Retrieves information about the current trial state for the paywall.
   * The method supports two types of trials: time-based and opens-based.
   * 
   * @throws {Error} If the request fails or paywall is not initialized
   * 
   * @example
   * // Get trial information
   * const trialInfo = await paywall.getTrialInfo();
   * 
   * if (trialInfo === 'no trial') {
   *   console.log('No trial available');
   * } else if ('expirationTime' in trialInfo) {
   *   // Handle time-based trial
   *   console.log(`Trial expires in ${trialInfo.expirationTime} ms`);
   * } else {
   *   // Handle opens-based trial
   *   console.log(`${trialInfo.remainingActions} actions remaining`);
   * }
   */
  getTrialInfo(): Promise<TrialInfo>;
}