import { UsageData, UsageTimePeriod, UsageStatsResult } from '../config/types.js';
import { PricingService } from './pricing.js';
/**
 * UsageService tracks token usage per model per day.
 *
 * Data is stored in ~/.mcp-rubber-duck/data/usage.json
 * Writes are debounced to avoid excessive disk I/O.
 */
export declare class UsageService {
    private usagePath;
    private data;
    private pricingService;
    private pendingWrites;
    private writeDebounceTimer;
    private debounceMs;
    constructor(pricingService: PricingService, options?: {
        dataDir?: string;
        debounceMs?: number;
    });
    private ensureDirectoryExists;
    private loadUsage;
    private saveUsage;
    private scheduleSave;
    private getTodayKey;
    /**
     * Record usage for a provider/model.
     */
    recordUsage(provider: string, model: string, promptTokens: number, completionTokens: number, error?: boolean): void;
    /**
     * Get usage statistics for a time period.
     */
    getStats(period: UsageTimePeriod): UsageStatsResult;
    private formatDate;
    /**
     * Flush pending writes immediately. Call on shutdown.
     */
    shutdown(): void;
    /**
     * Get raw usage data (for testing/debugging).
     * Returns a deep copy to prevent external mutation.
     */
    getRawData(): UsageData;
    /**
     * Clear all usage data (for testing).
     */
    clearData(): void;
}
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