/**
 * Emergency Content Truncation
 *
 * When message-level removal (sliding window) can't fit context into budget,
 * this truncates the CONTENT of the longest messages as a last resort.
 */
import type { ChatMessage } from "../types/index.js";
/**
 * Emergency content truncation: truncate the content of the longest messages
 * to fit within the available token budget.
 *
 * Strategy: Sort messages by content length (descending), truncate each
 * to a proportional share of the available budget until total fits.
 */
export declare function emergencyContentTruncation(messages: ChatMessage[], availableTokensForHistory: number, breakdown: {
    systemPrompt: number;
    conversationHistory: number;
    currentPrompt: number;
    toolDefinitions: number;
    fileAttachments: number;
}, provider?: string): ChatMessage[];