import type * as http from 'http';
/**
 * A marker the creator (or their agent) drops to hold every reload — the file watcher's and
 * `bitmagic reload`'s alike — for as long as it exists. Relative to the project root.
 *
 * It exists for one situation: a multiplayer room that must survive an agent's turn. Every reload
 * re-creates the game in every connected page, phones included, and a networked game re-created
 * is a new player id in a new room. Held reloads are dropped, not deferred: the next reload after
 * the marker goes shows the current build, and nothing fires by itself when it is removed.
 */
export declare const HOLD_RELOAD_FILE: string;
export declare function holdReloadPath(root: string): string;
export type BuildStatus = 'building' | 'ok' | 'failed';
export type SubscriberKind = 'shell' | 'phone';
export declare class ReloadBus {
    private readonly clients;
    private readonly keepalive;
    /** Absolute path of the hold marker, or null when this bus never holds (tests, embedding). */
    private readonly holdFile;
    /** One per process: the shell compares it across reconnects to notice a restarted `dev`. */
    readonly session: string;
    /** Fired on every 0→1 transition of the shell count — "a tab is watching this server". */
    onShellAttached: (() => void) | null;
    /** A reload was asked for and dropped because the hold marker exists. For the dev console. */
    onHeld: ((reason: string) => void) | null;
    constructor(options?: {
        session?: string;
        holdFile?: string;
    });
    get clientCount(): number;
    /** Browser tabs on the dev view, phones excluded. */
    get shellClientCount(): number;
    /**
     * Take over a request as an SSE stream. Never ends the response — it stays open until the browser
     * navigates away or the server closes.
     */
    subscribe(req: http.IncomingMessage, res: http.ServerResponse, kind?: SubscriberKind): void;
    send(event: string, data: unknown): void;
    /** Is the hold marker in place right now? Checked per reload, so it needs no watcher. */
    get held(): boolean;
    /** Push a reload to every subscriber — unless held, in which case nothing goes out. */
    reload(reason: string): boolean;
    build(status: BuildStatus, message?: string): void;
    close(): void;
}