/**

 * 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

 */

/**

 * `charCode` represents the actual "character code" and is safe to use with

 * `String.fromCharCode`. As such, only keys that correspond to printable

 * characters produce a valid `charCode`, the only exception to this is Enter.

 * The Tab-key is considered non-printable and does not have a `charCode`,

 * presumably because it does not produce a tab-character in browsers.

 *

 * @param {object} nativeEvent Native browser event.

 * @return {number} Normalized `charCode` property.

 */

function getEventCharCode(nativeEvent: KeyboardEvent): number {

  let charCode;

  const keyCode = nativeEvent.keyCode;

  if ('charCode' in nativeEvent) {

    charCode = nativeEvent.charCode;

    // FF does not set `charCode` for the Enter-key, check against `keyCode`.

    if (charCode === 0 && keyCode === 13) {

      charCode = 13;

    }

  } else {

    // IE8 does not implement `charCode`, but `keyCode` has the correct value.

    charCode = keyCode;

  }

  // IE and Edge (on Windows) and Chrome / Safari (on Windows and Linux)

  // report Enter as charCode 10 when ctrl is pressed.

  if (charCode === 10) {

    charCode = 13;

  }

  // Some non-printable keys are reported in `charCode`/`keyCode`, discard them.

  // Must not discard the (non-)printable Enter-key.

  if (charCode >= 32 || charCode === 13) {

    return charCode;

  }

  return 0;

}

export default getEventCharCode;