import type readline from 'readline';
import type { EventEmitter } from 'events';
import type { FlowrConfig } from '../../config';
export declare const defaultReplHint = ":help \u00B7 Tab completes \u00B7 :query @config +repl.hints=false to hide";
/** ANSI that draws the dimmed `hint` and restores the cursor to where it was. */
export declare function ghostHintShowSequence(hint: string): string;
export declare const ghostHintClearSequence = "\u001B[0K";
export interface GhostHintIO {
    stdin: EventEmitter & {
        isTTY?: boolean;
    };
    stdout: {
        isTTY?: boolean;
        columns?: number;
        write(s: string): unknown;
    };
}
export interface GhostHintOptions {
    hint?: string;
    suggest?: (line: string) => string;
}
export interface GhostHintController {
    show(): void;
    clear(): void;
}
/** Whether hints may be shown: enabled in the config and on an interactive TTY (honoring `NO_COLOR`/`TERM=dumb`). */
export declare function ghostHintEnabled(config: FlowrConfig, env?: NodeJS.ProcessEnv, stdout?: {
    isTTY?: boolean;
}, stdin?: {
    isTTY?: boolean;
}): boolean;
/**
 * Installs an opt-out ghost hint on the REPL prompt: a dim placeholder on the empty prompt and, as the user
 * types, a dim preview of the best Tab-completion. A no-op on non-interactive terminals (see
 * {@link ghostHintEnabled}) and whenever the text would not fit the line, so it can never wrap or corrupt output.
 */
export declare function installGhostHint(rl: readline.Interface, config: FlowrConfig, { hint, suggest }?: GhostHintOptions, io?: GhostHintIO): GhostHintController;