/**
 * S3-compatible storage controller (works with AWS S3 and MinIO)
 */
import { S3StorageConfig, StorageController } from "./types";
import { DownloadConfig, StorageListResult, UploadFileProps, UploadFileResult } from "@rebasepro/types";
/**
 * S3-compatible storage implementation
 * Works with AWS S3 and MinIO (with forcePathStyle option)
 */
export declare class S3StorageController implements StorageController {
    private config;
    private _client;
    constructor(config: S3StorageConfig);
    /**
     * Lazily create and cache the S3 client on first use
     */
    private getClient;
    getType(): "s3";
    /**
     * Validate file before upload
     */
    private validateFile;
    /**
     * Get the bucket name - either from parameter or config
     */
    private getBucket;
    putObject({ file, key, metadata, bucket }: UploadFileProps): Promise<UploadFileResult>;
    /**
     * Flatten nested metadata to string values (S3 requirement)
     */
    private flattenMetadata;
    getSignedUrl(key: string, bucket?: string): Promise<DownloadConfig>;
    getObject(key: string, bucket?: string): Promise<File | null>;
    deleteObject(key: string, bucket?: string): Promise<void>;
    listObjects(prefix: string, options?: {
        bucket?: string;
        maxResults?: number;
        pageToken?: string;
    }): Promise<StorageListResult>;
}