import { ValidationConfig } from '../interfaces/upload-options.interface';
import { MagicDetector } from './magic-bytes';
export interface ValidationResult {
    /** Final content type (detected content wins over the client hint). */
    mime: string;
    size: number;
}
/**
 * Validates a buffered file by size + real content type. The client MIME/extension is a
 * hint only; magic bytes are authoritative. Undetectable binary content is rejected.
 */
export declare class FileValidatorService {
    private readonly maxSize?;
    private readonly allow;
    private readonly magicBytes;
    private readonly signatureless;
    private readonly detector;
    constructor(config?: ValidationConfig, detector?: MagicDetector);
    /** Validate a full in-memory buffer (server-side upload path). */
    validate(input: {
        buffer: Buffer;
        size?: number;
        mimeType: string;
        originalName?: string;
    }): ValidationResult;
    /**
     * Validate from a header slice + known size — used to sniff a presigned upload at confirm
     * without downloading the whole object.
     */
    validateHeader(header: Buffer, meta: {
        size: number;
        mimeType: string;
    }): ValidationResult;
}