/**
 * One independently saved slice of player progress.
 *
 * ARCHITECTURE.md asks for a save built from several classes, each handling its
 * own part, keyed by the class. The key here is an explicit string rather than
 * `constructor.name` on purpose: release builds minify class names, and a
 * renamed class would silently orphan every existing save.
 */
export interface ISaveSection {
    /** Stable identifier. Never change it once a build has shipped. */
    readonly key: string;

    /** Current contents as a JSON-safe value. */
    save(): unknown;

    /**
     * Restores from a previously saved value. Must tolerate anything — an older
     * shape, a newer shape, or outright rubbish — by falling back to defaults
     * rather than throwing.
     */
    load(data: unknown): void;

    /** Returns to the state of a player who has never played. */
    reset(): void;
}