import { ILogger } from '../utils/Logger.js';
import { AttachmentService } from './AttachmentService.js';
import { LocalStorageAdapter } from './LocalStorageAdapter.js';
import { RemoteStorageAdapter } from './RemoteStorageAdapter.js';
import { AttachmentRecord } from './Schema.js';
import { AttachmentErrorHandler } from './AttachmentErrorHandler.js';
import { AttachmentContext } from './AttachmentContext.js';
/**
 * Orchestrates attachment synchronization between local and remote storage.
 * Handles uploads, downloads, deletions, and state transitions.
 *
 * @internal
 */
export declare class SyncingService {
    private attachmentService;
    private localStorage;
    private remoteStorage;
    private logger;
    private errorHandler?;
    constructor(attachmentService: AttachmentService, localStorage: LocalStorageAdapter, remoteStorage: RemoteStorageAdapter, logger: ILogger, errorHandler?: AttachmentErrorHandler);
    /**
     * Processes attachments based on their state (upload, download, or delete).
     * All updates are saved in a single batch after processing.
     *
     * @param attachments - Array of attachment records to process
     * @param context - Attachment context for database operations
     * @returns Promise that resolves when all attachments have been processed and saved
     */
    processAttachments(attachments: AttachmentRecord[], context: AttachmentContext): Promise<void>;
    /**
     * Uploads an attachment from local storage to remote storage.
     * On success, marks as SYNCED. On failure, defers to error handler or archives.
     *
     * @param attachment - The attachment record to upload
     * @returns Updated attachment record with new state
     * @throws Error if the attachment has no localUri
     */
    uploadAttachment(attachment: AttachmentRecord): Promise<AttachmentRecord>;
    /**
     * Downloads an attachment from remote storage to local storage.
     * Retrieves the file, converts to base64, and saves locally.
     * On success, marks as SYNCED. On failure, defers to error handler or archives.
     *
     * @param attachment - The attachment record to download
     * @returns Updated attachment record with local URI and new state
     */
    downloadAttachment(attachment: AttachmentRecord): Promise<AttachmentRecord>;
    /**
     * Deletes an attachment from both remote and local storage.
     * Removes the remote file, local file (if exists), and the attachment record.
     * On failure, defers to error handler or archives.
     *
     * @param attachment - The attachment record to delete
     * @param context - Attachment context for database operations
     * @returns Updated attachment record
     */
    deleteAttachment(attachment: AttachmentRecord, context: AttachmentContext): Promise<AttachmentRecord>;
    /**
     * Performs cleanup of archived attachments by removing their local files and records.
     * Errors during local file deletion are logged but do not prevent record deletion.
     */
    deleteArchivedAttachments(context: AttachmentContext): Promise<boolean>;
}