/**
 * One entry in a {@link SaveSlots} index: a save/profile slot's *display*
 * metadata, not its payload. The real save data lives in a `createSaveStore`
 * slot; this record is only what a save-select menu renders — an id, an optional
 * player-facing `name`, whether the slot is `empty`, when it was last written
 * (`savedAt`), and a free-string `meta` bag the game fills with whatever the
 * menu should show (level, playtime, location, chapter, a thumbnail ref, …).
 * `meta` keys are opaque to this model — it never reads or branches on them.
 */
export interface SaveSlotMeta {
    /** Stable slot id — pair it with the same slot in the game's `createSaveStore`. */
    id: string;
    /** Player-facing label (character name, save title). `undefined` until named. */
    name?: string;
    /** `true` when no save occupies this slot — the menu shows a "New Game" affordance. */
    empty: boolean;
    /** Clock time (ms) of the last {@link SaveSlots.write}, or `undefined` while empty. */
    savedAt?: number;
    /**
     * Free-string display fields the game owns and the menu renders as chips —
     * e.g. `{ chapter: "The Drowned Keep", playtime: "4h 12m", level: 8 }`. The
     * model never interprets these keys; they are pure passthrough to the renderer.
     */
    meta: Record<string, string | number>;
}
/** What a {@link SaveSlots.write} stamps onto a slot — a name and/or a fresh `meta` bag. */
export interface SaveSlotWrite {
    /** Player-facing label for the slot. Omit to keep the existing name. */
    name?: string;
    /** Replacement free-string display fields. Omit to keep the existing `meta`. */
    meta?: Record<string, string | number>;
    /** The save's own write time (ms) when the payload knows it; omit to use the index's clock. */
    savedAt?: number;
}
/** How a {@link createSaveSlots} index is wired. */
export interface SaveSlotsConfig {
    /** Injected clock (ms) used to stamp `savedAt`. Default `Date.now`. */
    now?: () => number;
    /**
     * Initial slots, in menu order. Any slot omitting `empty` is treated as empty.
     * When `capacity` is set and this is shorter, the list is padded with empty
     * slots (`slot-1`, `slot-2`, …) up to `capacity`.
     */
    slots?: SaveSlotMeta[];
    /**
     * Fixed number of slots the menu shows. When set, the index is padded with
     * empty slots up to this count and never grows past it. Omit for an
     * open-ended list that only holds the slots you seed.
     */
    capacity?: number;
}
/** Serializable state of a {@link SaveSlots} index, for save/restore. */
export interface SaveSlotsSnapshot {
    /** The slots in menu order. */
    slots: SaveSlotMeta[];
    /** The fixed capacity, or `undefined` for an open-ended list. */
    capacity: number | undefined;
}
/**
 * A serializable, observable index of save/profile slot *metadata* that a
 * save-select menu renders. It complements `createSaveStore` (which owns the
 * actual save payload and named slots) by carrying the per-slot display fields
 * the store does not: name, empty flag, last-saved time, and a free-string
 * `meta` bag the game fills. Nothing here is genre-specific.
 */
export interface SaveSlots {
    /**
     * Stamp a slot as written: sets `empty=false`, records `savedAt` via the
     * injected clock, and applies the given `name`/`meta`. Creates the slot if it
     * does not exist (subject to `capacity`). Returns the resulting slot record.
     */
    write(id: string, write?: SaveSlotWrite): SaveSlotMeta;
    /** Mark a slot empty, dropping its `name`, `savedAt`, and `meta`. Returns the cleared record, or `null` if the id is unknown. */
    clear(id: string): SaveSlotMeta | null;
    /** Rename a slot without touching its `savedAt`/`meta`. Returns the updated record, or `null` if the id is unknown. */
    rename(id: string, name: string): SaveSlotMeta | null;
    /** The slot with this id, or `null`. The returned record is a copy — mutating it does not affect the index. */
    get(id: string): SaveSlotMeta | null;
    /** All slots in menu order (copies). Powers the save-select grid. */
    list(): SaveSlotMeta[];
    /** The newest non-empty slot (highest `savedAt`), or `null` when every slot is empty — powers "Continue". */
    mostRecent(): SaveSlotMeta | null;
    /** Observe any change (write/clear/rename/restore). Returns an unsubscribe fn. */
    subscribe(listener: () => void): () => void;
    /** Serializable state for a save. */
    snapshot(): SaveSlotsSnapshot;
    /** Restore from a {@link SaveSlotsSnapshot}, replacing all slots. */
    restore(snapshot: SaveSlotsSnapshot): void;
}
/**
 * Create a {@link SaveSlots} index — the serializable, observable list of
 * save/profile slot metadata a save-select menu renders. It is a thin companion
 * to `createSaveStore`: the store owns the real save payload keyed by slot, this
 * owns only the display fields (name, empty, last-saved, and a free-string
 * `meta` bag) the menu shows. `write` stamps a slot saved on the injected clock,
 * `clear` empties one, `rename` relabels one, `mostRecent()` returns the newest
 * non-empty slot to power a "Continue" button, and `list()` feeds the New /
 * Continue / Load / Delete grid. `meta` keys are free strings the game owns —
 * the model never interprets them — and `snapshot`/`restore` round-trips the
 * whole index through a save.
 *
 * @capability save-slots serializable save-slot / profile metadata index — write/clear/rename/mostRecent over free-string per-slot meta, powering New/Continue/Load/Delete menus, with snapshot/restore
 */
export declare function createSaveSlots(config?: SaveSlotsConfig): SaveSlots;