/**
 * Discrete identifiers returned by {@link GNSupport.getPlatformType}.
 *
 * The string union is intentionally narrow — the SDK only branches
 * on these three values:
 * - `"cocos"` — the host runtime exposes the Cocos `cc` global with
 *   `cc.sys`. Detected before the browser check because the Cocos
 *   web build also exposes `window`.
 * - `"browser"` — the host exposes `window` but no Cocos `cc`
 *   global (vanilla browser, Electron renderer, embedded WebView).
 * - `"nodejs"` — neither of the above (Node.js, edge runtimes).
 */
type PlatformType = "cocos" | "browser" | "nodejs";
/**
 * Detects the host runtime once during {@link GNNetwork.init} and
 * exposes the result through small static accessors.
 *
 * Used for branching across runtime-specific code paths:
 * - {@link StorageService} picks between `cc.sys.localStorage`,
 *   `window.localStorage` and the npm `store` package.
 * - {@link HttpPeer} downgrades MsgPack HTTP requests to JSON in
 *   browsers because the browser HTTP path cannot reliably
 *   consume a MsgPack response across vendors.
 * - {@link NetworkingPeerAxiosRequest} only emits the custom
 *   `User-Agent` / `Content-Length` headers from Node.js because
 *   browsers refuse to let JavaScript override them.
 *
 * Detection runs exactly once because the runtime cannot change
 * mid-process; the cached values are accessed via the boolean
 * helpers without re-running the checks.
 */
export declare class GNSupport {
    /** Cached `_platformType === "browser"` flag. */
    private static _isBrowser;
    /** Cached `_platformType === "cocos"` flag. */
    private static _isCocosCreator;
    /** Cached platform identifier. */
    private static _platformType;
    /**
     * Init guard so {@link init} is idempotent — the SDK calls it
     * from {@link GNNetwork.init} but defensive call sites may
     * also invoke it.
     */
    private static _initialized;
    /**
     * Detects the runtime environment and caches the result.
     *
     * Detection order matters: Cocos must come first because the
     * Cocos web build still exposes `window`. Once `cc.sys` is
     * present we treat the host as Cocos even if `window` is also
     * defined.
     *
     * Safe to call multiple times — the {@link _initialized} guard
     * makes the second call a no-op.
     */
    static init(): void;
    /**
     * Returns whether the host runtime exposes a `window` global.
     *
     * Note that this returns `true` for both vanilla browsers and
     * the Cocos web build — when you need to distinguish those two
     * cases use {@link isCocosCreator} or
     * {@link getPlatformType} instead.
     */
    static isBrowser(): boolean;
    /**
     * Returns whether the host runtime is Cocos Creator (detected
     * via the `cc.sys` global).
     */
    static isCocosCreator(): boolean;
    /**
     * Returns whether the host runtime is Node.js (or any other
     * environment that exposes neither `window` nor `cc.sys`).
     */
    static isNodeJS(): boolean;
    /**
     * Returns the cached {@link PlatformType} discriminator.
     *
     * Useful for `switch` statements that need to handle the three
     * runtimes distinctly — see {@link StorageService.getString}
     * for the canonical example.
     */
    static getPlatformType(): PlatformType;
}
export {};