/**
 * Shared helpers for slot subflow builders.
 *
 * Pattern: utility module.
 * Role:    Tiny pure functions the slot builders share — hash, truncate,
 *          breakdown. Kept co-located to avoid cross-package import churn.
 */
import type { ContextSource, ContextSlot } from '../../events/types.js';
import type { BudgetPressureRecord, InjectionRecord, SlotComposition } from '../../recorders/core/types.js';
/** Non-cryptographic stable hash — sufficient for InjectionRecord dedup. */
export declare function fnv1a(input: string): string;
/** Truncate with ellipsis for contentSummary fields. */
export declare function truncate(s: string, n: number): string;
/** Aggregate injection chars/count per source — payload for SlotComposition. */
export declare function breakdown(injections: readonly InjectionRecord[]): Readonly<Partial<Record<ContextSource, {
    chars: number;
    count: number;
}>>>;
/**
 * Build a SlotComposition summary record from injections + budget cap.
 * Drop tracking is opt-in — pass `dropped` when the slot actually
 * evicted anything during composition.
 */
export declare function composeSlot(slot: ContextSlot, iteration: number, injections: readonly InjectionRecord[], budgetCap: number, orderingStrategy?: string, dropped?: {
    count: number;
    summaries: readonly string[];
}): SlotComposition;
/**
 * Overflow detector for slot compositions.
 *
 * Returns a `BudgetPressureRecord` when `used > cap`, otherwise `null`.
 * `cap <= 0` is the "no budget" sentinel (see buildMessageApiChart's
 * `{ cap: 0, used: 0 }` composition) — it never overflows.
 *
 * `planAction: 'none'` is the honest answer: the built-in slots evict and
 * truncate NOTHING, so the full content went to the LLM and this record is
 * the loud signal that the slot's budget is not being respected. Units are
 * CHARS despite the historical `*Tokens` field names.
 */
export declare function slotOverflow(composition: SlotComposition): BudgetPressureRecord | null;
/**
 * Human-facing warning text for a slot overflow. Says what actually
 * happened (nothing was truncated) and what to do about it — the typed
 * `context.budget_pressure` event carries the machine-readable truth.
 */
export declare function formatOverflowWarning(opts: {
    readonly pressure: BudgetPressureRecord;
    readonly itemCount: number;
    /** Singular noun for what filled the slot, e.g. 'tool definition'. */
    readonly itemNoun: string;
    /** Plural noun used in the "full … were sent" clause, e.g. 'definitions'. */
    readonly contentNoun: string;
    /** Actionable remedy sentence, ending with a period. */
    readonly remedy: string;
}): string;