import { FetchEventSourceInit } from '@microsoft/fetch-event-source';
import React, { Context } from 'react';

declare type SseURL = string;
declare type SseConnectionID = string;
interface EventMessage<T> {
    source: string;
    timestamp: number;
    event: T;
}
interface EventSourceMessage<T> {
    id: string;
    event: string;
    data: T;
    retry?: number;
}
/**
 * If SSE connection is lost (e.g. due to unreliable mobile network)
 * then reconnect is retried every 15 seconds. In case of having
 * a successful REST-call during that period, an SSE potentially
 * caused by this REST-call would be lost. To avoid this situation
 * the wakeup-callback can be used by REST-clients to trigger
 * SSE reconnect immediately instead of waiting to the end of the
 * 15 seconds period. If network is available the SSE connection
 * will be established before doing the REST-call and therefore
 * any potentially triggered SSE can be received and processed.
 */
declare type WakeupSseCallback = (() => void) | undefined;
declare type OnMessageFunction<T> = (ev: EventSourceMessage<T>) => void;
declare type GuiSseHook = <T>(onMessage: OnMessageFunction<T>, messageName?: string | RegExp) => WakeupSseCallback;
declare type GetConnectionFunction = (onMessage: OnMessageFunction<any>, messageName?: string | RegExp) => SseConnectionID;
declare type ReleaseConnectionFunction = (connectionId: SseConnectionID) => void;
declare type SseContextInterface = {
    wakeupSseCallback: WakeupSseCallback;
    getConnection: GetConnectionFunction;
    releaseConnection: ReleaseConnectionFunction;
};
interface SseProviderProps extends Omit<FetchEventSourceInit, 'fetch'> {
    Context: Context<SseContextInterface>;
    buildFetchApi: () => WindowOrWorkerGlobalScope['fetch'];
    url: SseURL;
}
declare const SseProvider: ({ url, Context, buildFetchApi, children, ...rest }: React.PropsWithChildren<SseProviderProps>) => JSX.Element;
declare const useSse: <T>(Context: React.Context<SseContextInterface>, onMessage: OnMessageFunction<T>, messageName?: string | RegExp) => WakeupSseCallback;

export { EventMessage, EventSourceMessage, GuiSseHook, OnMessageFunction, SseContextInterface, SseProvider, WakeupSseCallback, useSse };