import SyncItem from "./SyncItem";
import Collection from "./Collection";
import { SyncOptions } from "./types/SyncTypes";
import SyncStatus from "./types/SyncStatus";
declare class Synchronizer {
    /** Used to keep state of sync process. */
    private lastSyncedItem?;
    private _startDate?;
    private _endDate?;
    /** List of filtered items (removing conflicts, etc) that actually get sent to the destination collection for syncing. */
    private _itemsToSync;
    private _ignoredItems;
    private _conflictItems;
    private _syncStatus;
    private destCollection;
    private committed;
    private _rollbacked;
    get successfullyRollbacked(): boolean;
    get successfullyCommitted(): boolean;
    get syncStatus(): SyncStatus;
    get lastUpdatedAt(): Date | undefined;
    get itemsToSync(): SyncItem[];
    get conflictItems(): SyncItem[];
    get ignoredItems(): SyncItem[];
    constructor(destCollection: Collection);
    /**
     * This method sends the data to the destination collection.
     * It throws no exception related to WRITE/DELETE database operations.
     * READ operations used inside this method might fail, as well as errors due to wrong
     * arguments, but when a WRITE/DELETE fails, it sets the status accordingly for further inspection,
     * and does not throw any error.
     * This method can only be executed once. In order to sync again, create a new instance.
    */
    executeSync(lastSyncAt: Date | undefined, items: SyncItem[], options: SyncOptions): Promise<void>;
    private cleanUp;
    /** Executes a commit. If it does not succeed, status is set to `SyncStatus.UnexpectedError`. */
    commit(): Promise<void>;
    /** Executes a rollback. If it does not succeed, status is set to `SyncStatus.UnexpectedError`. */
    rollback(): Promise<void>;
    /**
     * Retries a function N times until it succeeds. If it doesn't succeed, it sets
     * the status to error.
     */
    private retryUntilSuccess;
    private syncItems;
    abort(): void;
    private itemHighestUpdatedAt;
    private areItemsSorted;
}
export default Synchronizer;