export interface StatModifier {
    add?: number;
    multiply?: number;
}
export type StatModifierSet<TStat extends string> = Partial<Record<TStat, StatModifier>>;
export interface CreateStatsOptions {
    now?: () => number;
}
/** One serializable modifier source in a {@link StatsSnapshot}. */
interface StatModifierSourceSnapshot<TStat extends string> {
    id: string;
    modifiers: StatModifierSet<TStat>;
    expiresAtMs?: number;
}
/** Complete plain-data state for a {@link Stats} runtime. */
export interface StatsSnapshot<TStat extends string> {
    base: Record<TStat, number>;
    sources: StatModifierSourceSnapshot<TStat>[];
}
export interface Stats<TStat extends string> {
    setBase(stat: TStat, value: number): void;
    getBase(stat: TStat): number;
    addSource(sourceId: string, modifiers: StatModifierSet<TStat>, options?: {
        expiresAtMs?: number;
    }): void;
    removeSource(sourceId: string): void;
    hasSource(sourceId: string, nowMs?: number): boolean;
    get(stat: TStat, nowMs?: number): number;
    pruneExpired(nowMs: number): string[];
    sources(): string[];
    /** Return a detached JSON-serializable copy of base values and modifier sources. */
    snapshot(): StatsSnapshot<TStat>;
    /** Replace all runtime state from caller-owned decoded snapshot data. */
    restore(snapshot: StatsSnapshot<TStat>): void;
}
/**
 * A stat block whose base values take stacking, timed buffs and debuffs, resolving the modified value on read.
 *
 * @capability stat-block base stats with stacking, expiring buffs and debuffs applied on read
 */
export declare function createStats<TStat extends string>(base: Record<TStat, number>, options?: CreateStatsOptions): Stats<TStat>;
export {};