import type { AgentSession } from '../agent/session.js';
export interface ContextSamplerOptions {
    sampleEveryNTurns?: number;
}
interface ContextUsageSource {
    getContextUsage(): Promise<{
        apiUsage?: {
            input_tokens: number;
            output_tokens: number;
            cache_creation_input_tokens: number;
            cache_read_input_tokens: number;
            context_window_tokens?: number;
        } | null;
        percentage?: number;
        totalTokens?: number;
        maxTokens?: number;
        autoCompactThreshold?: number;
        isAutoCompactEnabled: boolean;
        [key: string]: unknown;
    }>;
}
export declare class ContextSampler {
    private source;
    private readonly sampleEveryNTurns;
    private cachedRatio;
    private cachedDetail;
    private inFlight;
    private disposed;
    private generation;
    constructor(source: ContextUsageSource, opts?: ContextSamplerOptions);
    attach(session: AgentSession): this;
    getRatio(): number | undefined;
    getDetail(): {
        used: number;
        limit: number;
        percentage: number;
    } | undefined;
    refresh(): Promise<void>;
    onTurn(turnIndex: number): Promise<void>;
    reset(): void;
    dispose(): void;
    private doFetch;
}
export {};