/**
 * Predict the user's likely next prompt after an agent turn using a smol,
 * fast model. Native GJC port of the ghost-text prompt-suggestion behavior
 * from Claude Code: the prediction renders as dim ghost text in the empty
 * composer and Tab accepts it.
 */
import type { AgentMessage } from "@gajae-code/agent-core";
import { type Api, type Model } from "@gajae-code/ai/core";
import type { ModelRegistry } from "../config/model-registry";
import type { Settings } from "../config/settings";
export declare const PROMPT_SUGGESTION_MAX_WORDS = 12;
export declare const PROMPT_SUGGESTION_MAX_CHARS = 100;
/**
 * Strip wrapper tags and label prefixes a model sometimes adds despite being
 * told to reply with only the suggestion.
 */
export declare function sanitizePromptSuggestion(raw: string): string;
/**
 * Heuristic gate rejecting model output that would make a bad ghost-text
 * suggestion. Returns the rejection reason, or null when the text is usable.
 */
export declare function suppressPromptSuggestionReason(text: string): string | null;
/**
 * Build a compact recent-conversation transcript for the prediction request.
 * Returns null when there is no user message to predict from.
 */
export declare function buildPromptSuggestionContext(messages: AgentMessage[]): string | null;
/**
 * Generate a predicted next user prompt from the recent conversation.
 * Returns null when no usable suggestion is produced (silence is the
 * expected steady state).
 */
export declare function generatePromptSuggestion(messages: AgentMessage[], registry: ModelRegistry, settings: Settings, sessionId?: string, currentModel?: Model<Api>, metadataResolver?: (provider: string) => Record<string, unknown> | undefined): Promise<string | null>;