/**

 * 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.

 *

 * @emails react-core

 */

'use strict';

/**

 * Touch events state machine.

 *

 * Keeps track of the active pointers and allows them to be reflected in touch events.

 */

const activeTouches = new Map();

export function addTouch(touch) {

  const identifier = touch.identifier;

  const target = touch.target;

  if (!activeTouches.has(target)) {

    activeTouches.set(target, new Map());

  }

  if (activeTouches.get(target).get(identifier)) {

    // Do not allow existing touches to be overwritten

    console.error(

      'Touch with identifier %s already exists. Did not record touch start.',

      identifier,

    );

  } else {

    activeTouches.get(target).set(identifier, touch);

  }

}

export function updateTouch(touch) {

  const identifier = touch.identifier;

  const target = touch.target;

  if (activeTouches.get(target) != null) {

    activeTouches.get(target).set(identifier, touch);

  } else {

    console.error(

      'Touch with identifier %s does not exist. Cannot record touch move without a touch start.',

      identifier,

    );

  }

}

export function removeTouch(touch) {

  const identifier = touch.identifier;

  const target = touch.target;

  if (activeTouches.get(target) != null) {

    if (activeTouches.get(target).has(identifier)) {

      activeTouches.get(target).delete(identifier);

    } else {

      console.error(

        'Touch with identifier %s does not exist. Cannot record touch end without a touch start.',

        identifier,

      );

    }

  }

}

export function getTouches() {

  const touches = [];

  activeTouches.forEach((_, target) => {

    touches.push(...getTargetTouches(target));

  });

  return touches;

}

export function getTargetTouches(target) {

  if (activeTouches.get(target) != null) {

    return Array.from(activeTouches.get(target).values());

  }

  return [];

}

export function clear() {

  activeTouches.clear();

}