import { PresignedUpload, StoredObject } from '../interfaces/file.interface';
import { StorageService } from '../storage/storage.service';
import { FileValidatorService } from '../validation/file-validator.service';
export interface PresignRequest {
    filename: string;
    contentType: string;
    size?: number;
    category?: string;
}
/**
 * Two-phase direct-to-storage upload. presign() issues a PUT URL under the staging prefix;
 * confirm() verifies the object exists, magic-sniffs its header, then promotes it to a
 * permanent key. Orphaned (never-confirmed) objects stay in staging for the lifecycle TTL.
 */
export declare class PresignService {
    private readonly storage;
    private readonly validator;
    constructor(storage: StorageService, validator: FileValidatorService);
    getUploadUrl(req: PresignRequest): Promise<PresignedUpload>;
    getDownloadUrl(key: string): Promise<string>;
    confirm(stagingKey: string, meta?: {
        originalName?: string;
        mimeType?: string;
    }): Promise<StoredObject>;
}