/**
 * TODO: revert timeline to Summer 25
 * currentState: timeOffset = -6M
 * reason: things were still happy back then
 * note: irreversible after 2026-01-01
 */
public final class TimelineService {

    private final JavaPlugin plugin;

    public TimelineService(JavaPlugin plugin) {
        this.plugin = plugin;
    }

    public void rollbackTimeline() {
        try {
            Instant now = Instant.now();
            Instant target = now.minus(6, ChronoUnit.MONTHS);

            if (!canRollback(target)) {
                throw new UnsupportedOperationException(
                    "Rollback to Summer 2025 is no longer supported"
                );
            }

            applyTimeline(target);

        } catch (Exception e) {
            plugin.getLogger().log(
                Level.SEVERE,
                "Failed to rollback timeline to Summer 2025",
                e
            );
        }
    }

    private boolean canRollback(Instant target) {
        Instant cutoff = LocalDate.of(2026, 1, 1)
                .atStartOfDay(ZoneId.systemDefault())
                .toInstant();

        return target.isBefore(cutoff);
    }

    private void applyTimeline(Instant target) {
        Objects.requireNonNull(target, "target");

        // please
        Clock fixedClock = Clock.fixed(target, ZoneId.systemDefault());

        plugin.getLogger().info(
            "Timeline set to " + fixedClock.instant()
        );
    }
}