declare class PluginManager {
    private plugins;
    private requestIdCounter;
    private modifiedRequest;
    private processingContext;
    private modifiedResponse;
    private processedHooks;
    addPlugins(plugin: Plugin | Plugin[]): void;
    private hasBeenProcessed;
    private isPreRequestContext;
    private isPostRequestContext;
    private processPlugins;
    runPreRequestHooks(requestId: number, request: Request): Promise<Request | Response>;
    runPostRequestHooks(requestId: number, response: Response, originalRequest: Request): Promise<Response>;
    getModifiedRequest(requestId: number): Request;
    getModifiedResponse(requestId: number): Response;
    getPlugins(): Plugin[];
    generateNewRequestId(): number;
    clearProcessedPlugins(requestId: number): void;
}

declare enum PluginLifecycleHook {
    PRE_REQUEST = "preRequest",
    POST_REQUEST = "postRequest"
}
type PreRequestPluginHandlerContext = {
    request: Request;
    originalRequest: Request;
    pluginManager: PluginManager;
};
type PostRequestPluginHandlerContext = {
    response: Response;
    originalRequest: Request;
    pluginManager: PluginManager;
};
type PluginHandlerContext<T> = T extends PluginLifecycleHook.PRE_REQUEST ? PreRequestPluginHandlerContext : T extends PluginLifecycleHook.POST_REQUEST ? PostRequestPluginHandlerContext : never;
interface Plugin {
    onPreRequest?: (context: PluginHandlerContext<PluginLifecycleHook.PRE_REQUEST>) => Promise<void | Response>;
    onPostRequest?: (context: PluginHandlerContext<PluginLifecycleHook.POST_REQUEST>) => Promise<void | Response>;
}

declare class Fetcher {
    private pluginManager;
    use(plugin: Plugin | Plugin[]): void;
    fetch(input: RequestInfo, init?: RequestInit): Promise<Response>;
}

declare abstract class BasePlugin implements Plugin {
    onPreRequest(context: PluginHandlerContext<PluginLifecycleHook.PRE_REQUEST>): Promise<void | Response>;
    onPostRequest(context: PluginHandlerContext<PluginLifecycleHook.POST_REQUEST>): Promise<void | Response>;
}

export { BasePlugin, Fetcher, Plugin, PluginHandlerContext, PluginLifecycleHook, PostRequestPluginHandlerContext, PreRequestPluginHandlerContext };