/**

 * Copyright (c) Meta Platforms, Inc. and affiliates.

 *

 * This source code is licensed under the MIT license found in the

 * LICENSE file in the root directory of this source tree.

 * @flow

 */

import {rethrowCaughtError} from 'shared/ReactErrorUtils';

import type {ReactSyntheticEvent} from './ReactSyntheticEventType';

import accumulateInto from './accumulateInto';

import forEachAccumulated from './forEachAccumulated';

import {executeDispatchesInOrder} from './EventPluginUtils';

/**

 * Internal queue of events that have accumulated their dispatches and are

 * waiting to have their dispatches executed.

 */

let eventQueue: ?(Array<ReactSyntheticEvent> | ReactSyntheticEvent) = null;

/**

 * Dispatches an event and releases it back into the pool, unless persistent.

 *

 * @param {?object} event Synthetic event to be dispatched.

 * @private

 */

function executeDispatchesAndRelease(event: ReactSyntheticEvent) {

  if (event) {

    executeDispatchesInOrder(event);

    if (!event.isPersistent()) {

      event.constructor.release(event);

    }

  }

}

// $FlowFixMe[missing-local-annot]

function executeDispatchesAndReleaseTopLevel(e) {

  return executeDispatchesAndRelease(e);

}

export function runEventsInBatch(

  events: Array<ReactSyntheticEvent> | ReactSyntheticEvent | null,

) {

  if (events !== null) {

    eventQueue = accumulateInto(eventQueue, events);

  }

  // Set `eventQueue` to null before processing it so that we can tell if more

  // events get enqueued while processing.

  const processingEventQueue = eventQueue;

  eventQueue = null;

  if (!processingEventQueue) {

    return;

  }

  forEachAccumulated(processingEventQueue, executeDispatchesAndReleaseTopLevel);

  if (eventQueue) {

    throw new Error(

      'processEventQueue(): Additional events were enqueued while processing ' +

        'an event queue. Support for this has not yet been implemented.',

    );

  }

  // This would be a good time to rethrow if any of the event handlers threw.

  rethrowCaughtError();

}