/**
 * File Content Summarization Pipeline
 *
 * Provides utilities to detect when attached file content exceeds the
 * model's available context budget and to plan / build prompts for
 * LLM-driven summarization of the largest files.
 *
 * Design rationale:
 *  - Files are the #1 cause of context overflow when users attach
 *    multiple large documents (PDFs, spreadsheets, source code).
 *  - Rather than blindly truncating, we ask an LLM to produce a
 *    *context-aware* summary that retains the information most
 *    relevant to the user's actual question.
 *  - The caller (FileSummarizationService) is responsible for the
 *    actual LLM calls; this module is pure computation + types.
 */
import type { FileForSummarization, FileSummarizationCheckParams, FileSummarizationCheckResult, FileSummarizationPromptParams, FileSummarizationPlanEntry } from "../types/index.js";
/** Fraction of the context window reserved for non-file content overhead */
export declare const NON_FILE_RESERVE = 0.15;
/** Minimum tokens a single file can be allocated in the plan */
export declare const MIN_PER_FILE_TOKENS = 500;
/** Maximum tokens a single file can be allocated in the plan */
export declare const MAX_PER_FILE_TOKENS = 4000;
/**
 * Files with fewer estimated tokens than this threshold are never
 * summarized — they're already small enough to include verbatim.
 */
export declare const FILE_SUMMARIZATION_THRESHOLD = 1000;
/**
 * Check whether the attached files push the total input token count
 * beyond the model's available context window.
 *
 * When the total exceeds the budget, we calculate how many tokens are
 * available for files (after accounting for system prompt, conversation
 * history, current prompt, and tool definitions) and divide that
 * equally across all files to derive a per-file budget.
 */
export declare function shouldSummarizeFiles(params: FileSummarizationCheckParams): FileSummarizationCheckResult;
/**
 * Build the LLM prompt used to summarize a single file's content.
 *
 * The prompt is *context-aware*: it includes the user's original question
 * so the LLM can prioritise the most relevant parts of the file.
 */
export declare function buildFileSummarizationPrompt(params: FileSummarizationPromptParams): string;
/**
 * Decide which files need summarization and how much budget each gets.
 *
 * Strategy:
 *  1. Sort files largest-first.
 *  2. Walk through the list, marking the largest files for summarization
 *     until the cumulative saved tokens bring us under budget.
 *  3. Files below `FILE_SUMMARIZATION_THRESHOLD` are never summarized.
 */
export declare function planFileSummarization(files: FileForSummarization[], params: FileSummarizationCheckParams): FileSummarizationPlanEntry[];