/**
 * inputCeiling — how long a piece of text may be before the embedder stops
 * reading it, and what to say when one was longer.
 *
 * Pattern: one resolver + one message, shared by every door that embeds a
 *          corpus (`indexCorpus`, `indexFolder`, `indexDocuments`), so the
 *          arithmetic cannot drift between them.
 * Role:    memory/embedding layer — it sits beside the port whose field it
 *          reads.
 * Emits:   N/A.
 *
 * ── Why the number is resolved rather than fixed ────────────────────────────
 * An indexer's own default ceiling is a guess about a backend it has never
 * met, so it has to be the SMALLEST ceiling any embedder might have — 2,000
 * characters, the measured `localEmbedder` cliff. That default was safe and
 * wrong at the same time: safe for the on-device model it was measured on,
 * wrong by a factor of sixteen for a hosted model with an 8k-token window, and
 * silently wrong for anyone who raised their splitter's `maxChars` to a value
 * their embedder could read perfectly well. Measured in a production run: 6 of
 * 26 chunks clipped, with an embedder that would have read every one of them
 * whole.
 *
 * So the ceiling is resolved from three sources, most-specific first:
 *
 *   1. the caller's explicit `maxChunkChars` — they are allowed to know better
 *      than either of the below, and stating a number is how they say so;
 *   2. the embedder's declared `maxInputChars` — the number lives where the
 *      knowledge is;
 *   3. {@link DEFAULT_MAX_CHUNK_CHARS} — an embedder that declares nothing
 *      gets exactly the behaviour it had before this field existed.
 *
 * ── Why the message, and not just a number in a report ──────────────────────
 * A clipped chunk is stored WHOLE as the passage and indexed by its opening.
 * Retrieval then cannot find text that is plainly visible in the block the
 * model is later shown — which reads as "the corpus does not mention that",
 * not as a failure. The report has carried the list since 8.10.0 and nobody
 * reads a report that says everything went fine, so the count also gets said
 * out loud, once per run.
 */
import type { Embedder } from './types.js';
/**
 * The ceiling used when nothing better is known: the measured `localEmbedder`
 * cliff (512 wordpiece tokens ≈ 1,800–2,000 characters of English).
 *
 * It is the floor of the shipped range, deliberately — a ceiling that is too
 * LOW only over-reports, and a ceiling that is too HIGH clips in silence.
 */
export declare const DEFAULT_MAX_CHUNK_CHARS = 2000;
/** Where the ceiling in effect came from — the thing a message has to name. */
export type ChunkCeilingSource = 'explicit' | 'embedder' | 'default';
/** The ceiling in effect for one indexing call, and where it came from. */
export interface ChunkCeiling {
    /** Longest chunk, in characters, that this embedder reads whole. */
    readonly chars: number;
    readonly source: ChunkCeilingSource;
}
/**
 * Resolve the ceiling for one indexing call.
 *
 * A non-positive or non-finite value is treated as absent at BOTH levels: it
 * cannot describe a real ceiling, and honouring it would mark every chunk in
 * the corpus as truncated (or none of them) on the strength of a typo.
 */
export declare function resolveChunkCeiling(explicit: number | undefined, embedder: Pick<Embedder, 'maxInputChars'> | undefined): ChunkCeiling;
/**
 * The one sentence a run says out loud when something was clipped.
 *
 * It names the count (so the size of the hole is known), the ceiling AND where
 * it came from (so the reader knows which knob is theirs to turn), and the two
 * fixes — because "your index is silently incomplete" is useless without
 * "here is the line to change".
 */
export declare function truncationWarning(args: {
    /** The door that did the work, named as the caller wrote it. */
    readonly caller: string;
    /** How many pieces were longer than the ceiling. */
    readonly count: number;
    /** How many pieces there were in total. */
    readonly total: number;
    /** What the pieces are called at this door — 'chunk' or 'document'. */
    readonly noun: string;
    readonly ceiling: ChunkCeiling;
    /** The embedder's id, when it has one — which embedder's ceiling this is. */
    readonly embedderId?: string | undefined;
    /**
     * Where the affected ids can be read back, when the door hands back
     * something that carries them. Omitted at a door that returns only a count,
     * rather than pointing at a report that does not exist.
     */
    readonly idsIn?: string | undefined;
    /**
     * The "make the pieces smaller" half of the fix, in the caller's own terms —
     * a door that splits for you names its splitter; one that does not says how
     * to cut before calling it. Advice you cannot act on at the door you are
     * standing at is not advice.
     */
    readonly resplitHint?: string | undefined;
}): string;