import { ICalendarEvent } from '../types/CalendarTypes';
/**
 * Operation for the sync queue
 */
export interface IQueueOperation {
    id: string;
    type: 'create' | 'update' | 'delete';
    eventId: string;
    data: Partial<ICalendarEvent> | ICalendarEvent;
    timestamp: number;
    retryCount: number;
}
/**
 * IndexedDB Service for Calendar App
 * Handles local storage of events and sync queue
 */
export declare class IndexedDBService {
    private static readonly DB_NAME;
    private static readonly DB_VERSION;
    private static readonly EVENTS_STORE;
    private static readonly QUEUE_STORE;
    private static readonly SYNC_STATE_STORE;
    private db;
    private initialized;
    /**
     * Initialize and open the database
     */
    initialize(): Promise<void>;
    /**
     * Check if database is initialized
     */
    isInitialized(): boolean;
    /**
     * Ensure database is initialized
     */
    private ensureDB;
    /**
     * Get a single event by ID
     */
    getEvent(id: string): Promise<ICalendarEvent | null>;
    /**
     * Get all events
     */
    getAllEvents(): Promise<ICalendarEvent[]>;
    /**
     * Save an event (create or update)
     */
    saveEvent(event: ICalendarEvent): Promise<void>;
    /**
     * Delete an event
     */
    deleteEvent(id: string): Promise<void>;
    /**
     * Add operation to queue
     */
    addToQueue(operation: Omit<IQueueOperation, 'id'>): Promise<void>;
    /**
     * Get all queue operations (sorted by timestamp)
     */
    getQueue(): Promise<IQueueOperation[]>;
    /**
     * Remove operation from queue
     */
    removeFromQueue(id: string): Promise<void>;
    /**
     * Clear entire queue
     */
    clearQueue(): Promise<void>;
    /**
     * Save sync state value
     */
    setSyncState(key: string, value: any): Promise<void>;
    /**
     * Get sync state value
     */
    getSyncState(key: string): Promise<any | null>;
    /**
     * Serialize event for IndexedDB storage (convert Dates to ISO strings)
     */
    private serializeEvent;
    /**
     * Deserialize event from IndexedDB (convert ISO strings to Dates)
     */
    private deserializeEvent;
    /**
     * Close database connection
     */
    close(): void;
    /**
     * Delete entire database (for testing/reset)
     */
    static deleteDatabase(): Promise<void>;
    /**
     * Seed IndexedDB with mock data if empty
     */
    seedIfEmpty(mockDataUrl?: string): Promise<void>;
}