/**
 * TCP client for communicating with the CrossPad simulator's remote control server.
 * Protocol: newline-delimited JSON over TCP on localhost:19840.
 *
 * Two rules here are not style choices, they are defects this file exists to
 * not repeat (spec §3.8):
 *
 *  • One socket, one request at a time. The simulator parks every non-ping
 *    command on a single process-wide `s_responseReady` flag, so two requests
 *    in flight can each be handed the other's reply — and opening a second
 *    socket does not help, because the flag is shared by all of them.
 *  • Only reads are retried. v9 retried whatever timed out, so one slow
 *    `pad_press` became three presses the sim actually played.
 */
export interface RemoteResponse {
    ok: boolean;
    [key: string]: unknown;
}
export interface SendOptions {
    /** Response timeout in ms. Default 15 s — a kit load parks the LVGL thread. */
    timeoutMs?: number;
    /** Force the retry decision. Defaults to "only if the command is a read". */
    retry?: boolean;
}
/** Whether `cmd` may be re-sent when the first attempt times out. */
export declare function isReadCommand(cmd: unknown): boolean;
/** Close the socket (simulator killed, tests). The next send reconnects. */
export declare function closeSimConnection(): void;
/**
 * Send a JSON command to the running simulator and return the response.
 * Requests never overlap; a read that times out is retried, a command with a
 * side effect is not.
 */
export declare function sendRemoteCommand(command: Record<string, unknown>, options?: SendOptions): Promise<RemoteResponse>;
/**
 * Check if the simulator's remote control server is reachable. One short
 * attempt: callers poll this in a loop, so a retry ladder here would only make
 * "not up yet" take a minute to answer.
 */
export declare function isSimulatorRunning(): Promise<boolean>;