/**
 * Platform-neutral attachment limit selection.
 *
 * Pure functions used by the platform layer before enqueueing a message:
 * filter inbound attachments against per-file and total size limits.
 */
import { type AttachmentMeta } from '../types.js';
export interface AttachmentLimits {
    maxFileBytes: number;
    maxTotalBytes: number;
}
export type AttachmentRejectionReason = 'file-too-large' | 'total-too-large';
export interface RejectedAttachment {
    attachment: AttachmentMeta;
    reason: AttachmentRejectionReason;
    limitBytes: number;
}
export interface AttachmentSelection {
    accepted: AttachmentMeta[];
    rejected: RejectedAttachment[];
    totalAcceptedBytes: number;
}
export declare function selectAttachmentsWithinLimits(attachments: AttachmentMeta[], limits: AttachmentLimits): AttachmentSelection;
export declare function buildAttachmentOnlyPrompt(attachmentCount: number): string;