class Subscription String userId; SubscriptionPlan plan; LocalDate startDate; LocalDate endDate; boolean isActive();

abstract class Video String videoId; String title; int durationSeconds; String url; boolean isFree;

class Movie extends Video String director; int releaseYear;

class WatchHistory String userId; String videoId; int lastTimestampSeconds; LocalDateTime lastWatchedAt;

enum PlanType FREE_TRIAL, MONTHLY, YEARLY, PREMIUM