export class SessionLifecycle {
	private current = 0;
	private deferred: Array<() => void> = [];
	private shutDown = false;

	start(): void {
		this.current++;
		this.shutDown = false;
		this.flushDeferred();
	}

	shutdown(): void {
		this.shutDown = true;
		this.deferred = [];
	}

	isCurrent(generation?: number): boolean {
		if (this.shutDown) return false;
		if (generation === undefined) return true;
		return generation === this.current;
	}

	currentGeneration(): number {
		return this.current;
	}

	defer(fn: () => void): void {
		if (this.shutDown) return;
		this.deferred.push(fn);
	}

	private flushDeferred(): void {
		const pending = this.deferred;
		this.deferred = [];
		for (const fn of pending) {
			try {
				fn();
			} catch {
				// ponytail: silent fallback — deferred tasks are best-effort
			}
		}
	}
}