<?php

/**

 * WordPress implementation for PHP functions either missing from older PHP versions or not included by default.

 *

 * This file is loaded extremely early and the functions can be relied upon by drop-ins.

 * Ergo, please ensure you do not rely on external functions when writing code for this file.

 * Only use functions built into PHP or are defined in this file and have adequate testing

 * and error suppression to ensure the file will run correctly and not break websites.

 *

 * @package PHP

 * @access private

 */

// If gettext isn't available.

if ( ! function_exists( '_' ) ) {

	function _( $message ) {

		return $message;

	}

}

/**

 * Returns whether PCRE/u (PCRE_UTF8 modifier) is available for use.

 *

 * @ignore

 * @since 4.2.2

 * @access private

 *

 * @param bool $set - Used for testing only

 *             null   : default - get PCRE/u capability

 *             false  : Used for testing - return false for future calls to this function

 *             'reset': Used for testing - restore default behavior of this function

 */

function _wp_can_use_pcre_u( $set = null ) {

	static $utf8_pcre = 'reset';

	if ( null !== $set ) {

		$utf8_pcre = $set;

	}

	if ( 'reset' === $utf8_pcre ) {

		// phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- intentional error generated to detect PCRE/u support.

		$utf8_pcre = @preg_match( '/^./u', 'a' );

	}

	return $utf8_pcre;

}

/**

 * Indicates if a given slug for a character set represents the UTF-8 text encoding.

 *

 * A charset is considered to represent UTF-8 if it is a case-insensitive match

 * of "UTF-8" with or without the hyphen.

 *

 * Example:

 *

 *     true  === _is_utf8_charset( 'UTF-8' );

 *     true  === _is_utf8_charset( 'utf8' );

 *     false === _is_utf8_charset( 'latin1' );

 *     false === _is_utf8_charset( 'UTF 8' );

 *

 *     // Only strings match.

 *     false === _is_utf8_charset( [ 'charset' => 'utf-8' ] );

 *

 * `is_utf8_charset` should be used outside of this file.

 *

 * @ignore

 * @since 6.6.1

 *

 * @param string $charset_slug Slug representing a text character encoding, or "charset".

 *                             E.g. "UTF-8", "Windows-1252", "ISO-8859-1", "SJIS".

 *

 * @return bool Whether the slug represents the UTF-8 encoding.

 */

function _is_utf8_charset( $charset_slug ) {

	if ( ! is_string( $charset_slug ) ) {

		return false;

	}

	return (

		0 === strcasecmp( 'UTF-8', $charset_slug ) ||

		0 === strcasecmp( 'UTF8', $charset_slug )

	);

}

if ( ! function_exists( 'mb_substr' ) ) :

	/**

	 * Compat function to mimic mb_substr().

	 *

	 * @ignore

	 * @since 3.2.0

	 *

	 * @see _mb_substr()

	 *

	 * @param string      $string   The string to extract the substring from.

	 * @param int         $start    Position to being extraction from in `$string`.

	 * @param int|null    $length   Optional. Maximum number of characters to extract from `$string`.

	 *                              Default null.

	 * @param string|null $encoding Optional. Character encoding to use. Default null.

	 * @return string Extracted substring.

	 */

	function mb_substr( $string, $start, $length = null, $encoding = null ) { // phpcs:ignore Universal.NamingConventions.NoReservedKeywordParameterNames.stringFound

		return _mb_substr( $string, $start, $length, $encoding );

	}

endif;

/**

 * Internal compat function to mimic mb_substr().

 *

 * Only understands UTF-8 and 8bit. All other character sets will be treated as 8bit.

 * For `$encoding === UTF-8`, the `$str` input is expected to be a valid UTF-8 byte

 * sequence. The behavior of this function for invalid inputs is undefined.

 *

 * @ignore

 * @since 3.2.0

 *

 * @param string      $str      The string to extract the substring from.

 * @param int         $start    Position to being extraction from in `$str`.

 * @param int|null    $length   Optional. Maximum number of characters to extract from `$str`.

 *                              Default null.

 * @param string|null $encoding Optional. Character encoding to use. Default null.

 * @return string Extracted substring.

 */

function _mb_substr( $str, $start, $length = null, $encoding = null ) {

	if ( null === $str ) {

		return '';

	}

	if ( null === $encoding ) {

		$encoding = get_option( 'blog_charset' );

	}

	/*

	 * The solution below works only for UTF-8, so in case of a different

	 * charset just use built-in substr().

	 */

	if ( ! _is_utf8_charset( $encoding ) ) {

		return is_null( $length ) ? substr( $str, $start ) : substr( $str, $start, $length );

	}

	if ( _wp_can_use_pcre_u() ) {

		// Use the regex unicode support to separate the UTF-8 characters into an array.

		preg_match_all( '/./us', $str, $match );

		$chars = is_null( $length ) ? array_slice( $match[0], $start ) : array_slice( $match[0], $start, $length );

		return implode( '', $chars );

	}

	$regex = '/(

		[\x00-\x7F]                  # single-byte sequences   0xxxxxxx

		| [\xC2-\xDF][\x80-\xBF]       # double-byte sequences   110xxxxx 10xxxxxx

		| \xE0[\xA0-\xBF][\x80-\xBF]   # triple-byte sequences   1110xxxx 10xxxxxx * 2

		| [\xE1-\xEC][\x80-\xBF]{2}

		| \xED[\x80-\x9F][\x80-\xBF]

		| [\xEE-\xEF][\x80-\xBF]{2}

		| \xF0[\x90-\xBF][\x80-\xBF]{2} # four-byte sequences   11110xxx 10xxxxxx * 3

		| [\xF1-\xF3][\x80-\xBF]{3}

		| \xF4[\x80-\x8F][\x80-\xBF]{2}

	)/x';

	// Start with 1 element instead of 0 since the first thing we do is pop.

	$chars = array( '' );

	do {

		// We had some string left over from the last round, but we counted it in that last round.

		array_pop( $chars );

		/*

		 * Split by UTF-8 character, limit to 1000 characters (last array element will contain

		 * the rest of the string).

		 */

		$pieces = preg_split( $regex, $str, 1000, PREG_SPLIT_DELIM_CAPTURE | PREG_SPLIT_NO_EMPTY );

		$chars = array_merge( $chars, $pieces );

		// If there's anything left over, repeat the loop.

	} while ( count( $pieces ) > 1 && $str = array_pop( $pieces ) );

	return implode( '', array_slice( $chars, $start, $length ) );

}

if ( ! function_exists( 'mb_strlen' ) ) :

	/**

	 * Compat function to mimic mb_strlen().

	 *

	 * @ignore

	 * @since 4.2.0

	 *

	 * @see _mb_strlen()

	 *

	 * @param string      $string   The string to retrieve the character length from.

	 * @param string|null $encoding Optional. Character encoding to use. Default null.

	 * @return int String length of `$string`.

	 */

	function mb_strlen( $string, $encoding = null ) { // phpcs:ignore Universal.NamingConventions.NoReservedKeywordParameterNames.stringFound

		return _mb_strlen( $string, $encoding );

	}

endif;

/**

 * Internal compat function to mimic mb_strlen().

 *

 * Only understands UTF-8 and 8bit. All other character sets will be treated as 8bit.

 * For `$encoding === UTF-8`, the `$str` input is expected to be a valid UTF-8 byte

 * sequence. The behavior of this function for invalid inputs is undefined.

 *

 * @ignore

 * @since 4.2.0

 *

 * @param string      $str      The string to retrieve the character length from.

 * @param string|null $encoding Optional. Character encoding to use. Default null.

 * @return int String length of `$str`.

 */

function _mb_strlen( $str, $encoding = null ) {

	if ( null === $encoding ) {

		$encoding = get_option( 'blog_charset' );

	}

	/*

	 * The solution below works only for UTF-8, so in case of a different charset

	 * just use built-in strlen().

	 */

	if ( ! _is_utf8_charset( $encoding ) ) {

		return strlen( $str );

	}

	if ( _wp_can_use_pcre_u() ) {

		// Use the regex unicode support to separate the UTF-8 characters into an array.

		preg_match_all( '/./us', $str, $match );

		return count( $match[0] );

	}

	$regex = '/(?:

		[\x00-\x7F]                  # single-byte sequences   0xxxxxxx

		| [\xC2-\xDF][\x80-\xBF]       # double-byte sequences   110xxxxx 10xxxxxx

		| \xE0[\xA0-\xBF][\x80-\xBF]   # triple-byte sequences   1110xxxx 10xxxxxx * 2

		| [\xE1-\xEC][\x80-\xBF]{2}

		| \xED[\x80-\x9F][\x80-\xBF]

		| [\xEE-\xEF][\x80-\xBF]{2}

		| \xF0[\x90-\xBF][\x80-\xBF]{2} # four-byte sequences   11110xxx 10xxxxxx * 3

		| [\xF1-\xF3][\x80-\xBF]{3}

		| \xF4[\x80-\x8F][\x80-\xBF]{2}

	)/x';

	// Start at 1 instead of 0 since the first thing we do is decrement.

	$count = 1;

	do {

		// We had some string left over from the last round, but we counted it in that last round.

		--$count;

		/*

		 * Split by UTF-8 character, limit to 1000 characters (last array element will contain

		 * the rest of the string).

		 */

		$pieces = preg_split( $regex, $str, 1000 );

		// Increment.

		$count += count( $pieces );

		// If there's anything left over, repeat the loop.

	} while ( $str = array_pop( $pieces ) );

	// Fencepost: preg_split() always returns one extra item in the array.

	return --$count;

}

// sodium_crypto_box() was introduced in PHP 7.2.

if ( ! function_exists( 'sodium_crypto_box' ) ) {

	require ABSPATH . WPINC . '/sodium_compat/autoload.php';

}

if ( ! function_exists( 'is_countable' ) ) {

	/**

	 * Polyfill for is_countable() function added in PHP 7.3.

	 *

	 * Verify that the content of a variable is an array or an object

	 * implementing the Countable interface.

	 *

	 * @since 4.9.6

	 *

	 * @param mixed $value The value to check.

	 * @return bool True if `$value` is countable, false otherwise.

	 */

	function is_countable( $value ) {

		return ( is_array( $value )

			|| $value instanceof Countable

			|| $value instanceof SimpleXMLElement

			|| $value instanceof ResourceBundle

		);

	}

}

if ( ! function_exists( 'array_key_first' ) ) {

	/**

	 * Polyfill for array_key_first() function added in PHP 7.3.

	 *

	 * Get the first key of the given array without affecting

	 * the internal array pointer.

	 *

	 * @since 5.9.0

	 *

	 * @param array $array An array.

	 * @return string|int|null The first key of array if the array

	 *                         is not empty; `null` otherwise.

	 */

	function array_key_first( array $array ) { // phpcs:ignore Universal.NamingConventions.NoReservedKeywordParameterNames.arrayFound

		if ( empty( $array ) ) {

			return null;

		}

		foreach ( $array as $key => $value ) {

			return $key;

		}

	}

}

if ( ! function_exists( 'array_key_last' ) ) {

	/**

	 * Polyfill for `array_key_last()` function added in PHP 7.3.

	 *

	 * Get the last key of the given array without affecting the

	 * internal array pointer.

	 *

	 * @since 5.9.0

	 *

	 * @param array $array An array.

	 * @return string|int|null The last key of array if the array

	 *.                        is not empty; `null` otherwise.

	 */

	function array_key_last( array $array ) { // phpcs:ignore Universal.NamingConventions.NoReservedKeywordParameterNames.arrayFound

		if ( empty( $array ) ) {

			return null;

		}

		end( $array );

		return key( $array );

	}

}

if ( ! function_exists( 'array_is_list' ) ) {

	/**

	 * Polyfill for `array_is_list()` function added in PHP 8.1.

	 *

	 * Determines if the given array is a list.

	 *

	 * An array is considered a list if its keys consist of consecutive numbers from 0 to count($array)-1.

	 *

	 * @see https://github.com/symfony/polyfill-php81/tree/main

	 *

	 * @since 6.5.0

	 *

	 * @param array<mixed> $arr The array being evaluated.

	 * @return bool True if array is a list, false otherwise.

	 */

	function array_is_list( $arr ) {

		if ( ( array() === $arr ) || ( array_values( $arr ) === $arr ) ) {

			return true;

		}

		$next_key = -1;

		foreach ( $arr as $k => $v ) {

			if ( ++$next_key !== $k ) {

				return false;

			}

		}

		return true;

	}

}

if ( ! function_exists( 'str_contains' ) ) {

	/**

	 * Polyfill for `str_contains()` function added in PHP 8.0.

	 *

	 * Performs a case-sensitive check indicating if needle is

	 * contained in haystack.

	 *

	 * @since 5.9.0

	 *

	 * @param string $haystack The string to search in.

	 * @param string $needle   The substring to search for in the `$haystack`.

	 * @return bool True if `$needle` is in `$haystack`, otherwise false.

	 */

	function str_contains( $haystack, $needle ) {

		if ( '' === $needle ) {

			return true;

		}

		return false !== strpos( $haystack, $needle );

	}

}

if ( ! function_exists( 'str_starts_with' ) ) {

	/**

	 * Polyfill for `str_starts_with()` function added in PHP 8.0.

	 *

	 * Performs a case-sensitive check indicating if

	 * the haystack begins with needle.

	 *

	 * @since 5.9.0

	 *

	 * @param string $haystack The string to search in.

	 * @param string $needle   The substring to search for in the `$haystack`.

	 * @return bool True if `$haystack` starts with `$needle`, otherwise false.

	 */

	function str_starts_with( $haystack, $needle ) {

		if ( '' === $needle ) {

			return true;

		}

		return 0 === strpos( $haystack, $needle );

	}

}

if ( ! function_exists( 'str_ends_with' ) ) {

	/**

	 * Polyfill for `str_ends_with()` function added in PHP 8.0.

	 *

	 * Performs a case-sensitive check indicating if

	 * the haystack ends with needle.

	 *

	 * @since 5.9.0

	 *

	 * @param string $haystack The string to search in.

	 * @param string $needle   The substring to search for in the `$haystack`.

	 * @return bool True if `$haystack` ends with `$needle`, otherwise false.

	 */