import type { TFileValidator } from '../../shared-types';
export interface IValidateFileOptions {
    allowedFormats?: string[];
    maxFileSize?: string | number;
    formatErrorMessage?: string;
    sizeErrorMessage?: string;
    onFileValidation?: TFileValidator;
}
/** Apply `{formats}` / `{maxSize}` placeholders to a user-supplied message, falling back to the default. */
export declare function applyErrorTemplate(template: string | undefined | null, fallback: string, placeholders: Record<string, string>): string;
/**
 * Run the shared validation pipeline (format → size → user callback).
 * Returns the first error string, or `null` if the file is accepted.
 *
 * The `onFileValidation` callback is called last and can veto an otherwise-valid file.
 */
export declare function validateFile(file: File, options: IValidateFileOptions): string | null;
/** Detect whether a file (or an item with `.file` and `.attributes.targetFilename`) is an image. */
export declare function isImageFileLike(input: {
    file?: File | null;
    attributes?: {
        targetFilename?: string;
    };
}): boolean;