Function rollback

src/engine/lifecycle.ts:503–530

(engine: VisualNovelEngine)

}

export async function rollback (engine: VisualNovelEngine): Promise<void> {
	const allowRollback = engine.setting ('AllowRollback') === true;

	if (!allowRollback) {
		return;
	}

	const stateObj = engine.state() as { step: number; label: string };

	if (stateObj.step === 0) {
		const jumpHistory = engine.history ('jump') as { destination: { label: string; step: number } }[];
		const jump = [...jumpHistory].reverse ().find (o => {
			return o.destination.label === stateObj.label && o.destination.step === 0;
		});

		if (typeof jump === 'undefined') {
			engine.debug.debug ('Will not attempt rollback since this is the beginning of the game.');
			return;
		}
	}

	await shouldRollback (engine);

	engine.global ('_engine_block', true);

	await willRollback (engine);
	await engine.previous ();
}

// ============================================================================
// Proceed/Rollback Checks