includes/collation/IcuCollation.php - mediawiki/core - Gitiles

 <?php
 /**
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License along
  * with this program; if not, write to the Free Software Foundation, Inc.,
  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  * http://www.gnu.org/copyleft/gpl.html
  *
  * @file
  */

 use MediaWiki\Languages\LanguageFactory;
 use MediaWiki\MediaWikiServices;

 /**
  * @since 1.16.3
  */
 class IcuCollation extends Collation {
 	private const FIRST_LETTER_VERSION = 4;

 	/** @var Collator */
 	private $primaryCollator;

 	/** @var Collator */
 	private $mainCollator;

 	/** @var string */
 	private $locale;

 	/** @var Language */
 	protected $digitTransformLanguage;

 	/** @var bool */
 	private $useNumericCollation = false;

 	/** @var array */
 	private $firstLetterData;

 	/**
 	 * Unified CJK blocks.
 	 *
 	 * The same definition of a CJK block must be used for both Collation and
 	 * generateCollationData.php. These blocks are omitted from the first
 	 * letter data, as an optimisation measure and because the default UCA table
 	 * is pretty useless for sorting Chinese text anyway. Japanese and Korean
 	 * blocks are not included here, because they are smaller and more useful.
 	 */
 	private const CJK_BLOCKS = [
 		[ 0x2E80, 0x2EFF ], // CJK Radicals Supplement
 		[ 0x2F00, 0x2FDF ], // Kangxi Radicals
 		[ 0x2FF0, 0x2FFF ], // Ideographic Description Characters
 		[ 0x3000, 0x303F ], // CJK Symbols and Punctuation
 		[ 0x31C0, 0x31EF ], // CJK Strokes
 		[ 0x3200, 0x32FF ], // Enclosed CJK Letters and Months
 		[ 0x3300, 0x33FF ], // CJK Compatibility
 		[ 0x3400, 0x4DBF ], // CJK Unified Ideographs Extension A
 		[ 0x4E00, 0x9FFF ], // CJK Unified Ideographs
 		[ 0xF900, 0xFAFF ], // CJK Compatibility Ideographs
 		[ 0xFE30, 0xFE4F ], // CJK Compatibility Forms
 		[ 0x20000, 0x2A6DF ], // CJK Unified Ideographs Extension B
 		[ 0x2A700, 0x2B73F ], // CJK Unified Ideographs Extension C
 		[ 0x2B740, 0x2B81F ], // CJK Unified Ideographs Extension D
 		[ 0x2F800, 0x2FA1F ], // CJK Compatibility Ideographs Supplement
 	];

 	/**
 	 * Additional characters (or character groups) to be considered separate
 	 * letters for given languages, or to be removed from the list of such
 	 * letters (denoted by keys starting with '-').
 	 *
 	 * These are additions to (or subtractions from) the data stored in the
 	 * first-letters-root.php data file (which among others includes full basic
 	 * Latin, Cyrillic and Greek alphabets).
 	 *
 	 * "Separate letter" is a letter that would have a separate heading/section
 	 * for it in a dictionary or a phone book in this language. This data isn't
 	 * used for sorting (the ICU library handles that), only for deciding which
 	 * characters (or character groups) to use as headings.
 	 *
 	 * Initially generated based on the primary level of Unicode collation
 	 * tailorings available at http://developer.mimer.com/charts/tailorings.htm ,
 	 * later modified.
 	 *
 	 * Empty arrays are intended; this signifies that the data for the language is
 	 * available and that there are, in fact, no additional letters to consider.
 	 */
 	private const TAILORING_FIRST_LETTERS = [
 		'af' => [],
 		'am' => [],
 		'ar' => [],
 		'as' => [ "\u{0982}", "\u{0981}", "\u{0983}", "\u{09CE}", "ক্ষ " ],
 		'ast' => [ "Ch", "Ll", "Ñ" ], // not in libicu
 		'az' => [ "Ç", "Ə", "Ğ", "İ", "Ö", "Ş", "Ü" ],
 		'be' => [ "Ё" ],
 		'be-tarask' => [ "Ё" ],
 		'bg' => [],
 		'bn' => [ 'ং', 'ঃ', 'ঁ' ],
 		'bn@collation=traditional' => [
 			'ং', 'ঃ', 'ঁ', 'ক্', 'খ্', 'গ্', 'ঘ্', 'ঙ্', 'চ্', 'ছ্', 'জ্', 'ঝ্',
 			'ঞ্', 'ট্', 'ঠ্', 'ড্', 'ঢ্', 'ণ্', 'ৎ', 'থ্', 'দ্', 'ধ্', 'ন্', 'প্',
 			'ফ্', 'ব্', 'ভ্', 'ম্', 'য্', 'র্', 'ৰ্', 'ল্', 'ৱ্', 'শ্', 'ষ্', 'স্', 'হ্'
 		],
 		'bo' => [],
 		'br' => [ "Ch", "C'h" ],
 		'bs' => [ "Č", "Ć", "Dž", "Đ", "Lj", "Nj", "Š", "Ž" ],
 		'bs-Cyrl' => [],
 		'ca' => [],
 		'chr' => [],
 		'co' => [], // not in libicu
 		'cs' => [ "Č", "Ch", "Ř", "Š", "Ž" ],
 		'cy' => [ "Ch", "Dd", "Ff", "Ng", "Ll", "Ph", "Rh", "Th" ],
 		'da' => [ "Æ", "Ø", "Å" ],
 		'de' => [],
 		'de-AT@collation=phonebook' => [ 'ä', 'ö', 'ü', 'ß' ],
 		'dsb' => [ "Č", "Ć", "Dź", "Ě", "Ch", "Ł", "Ń", "Ŕ", "Š", "Ś", "Ž", "Ź" ],
 		'ee' => [ "Dz", "Ɖ", "Ɛ", "Ƒ", "Gb", "Ɣ", "Kp", "Ny", "Ŋ", "Ɔ", "Ts", "Ʋ" ],
 		'el' => [],
 		'en' => [],
 		'eo' => [ "Ĉ", "Ĝ", "Ĥ", "Ĵ", "Ŝ", "Ŭ" ],
 		'es' => [ "Ñ" ],
 		'et' => [ "Š", "Ž", "Õ", "Ä", "Ö", "Ü" ],
 		'eu' => [ "Ñ" ], // not in libicu
 		'fa' => [
 			// RTL, let's put each letter on a new line
 			"آ",
 			"ء",
 			"ه",
 			"ا",
 			"و"
 		],
 		'fi' => [ "Å", "Ä", "Ö" ],
 		'fil' => [ "Ñ", "Ng" ],
 		'fo' => [ "Á", "Ð", "Í", "Ó", "Ú", "Ý", "Æ", "Ø", "Å" ],
 		'fr' => [],
 		'fr-CA' => [], // fr-CA sorts accents slightly different from fr.
 		'fur' => [ "À", "Á", "Â", "È", "Ì", "Ò", "Ù" ], // not in libicu
 		'fy' => [], // not in libicu
 		'ga' => [],
 		'gd' => [], // not in libicu
 		'gl' => [ "Ch", "Ll", "Ñ" ],
 		'gu' => [ "\u{0A82}", "\u{0A83}", "\u{0A81}", "\u{0AB3}" ],
 		'ha' => [ 'Ɓ', 'Ɗ', 'Ƙ', 'Sh', 'Ts', 'Ƴ' ],
 		'haw' => [ 'ʻ' ],
 		'he' => [],
 		'hi' => [ "\u{0902}", "\u{0903}" ],
 		'hr' => [ "Č", "Ć", "Dž", "Đ", "Lj", "Nj", "Š", "Ž" ],
 		'hsb' => [ "Č", "Dź", "Ě", "Ch", "Ł", "Ń", "Ř", "Š", "Ć", "Ž" ],
 		'hu' => [ "Cs", "Dz", "Dzs", "Gy", "Ly", "Ny", "Ö", "Sz", "Ty", "Ü", "Zs" ],
 		'hy' => [ "և" ],
 		'id' => [],
 		'ig' => [ "Ch", "Gb", "Gh", "Gw", "Ị", "Kp", "Kw", "Ṅ", "Nw", "Ny", "Ọ", "Sh", "Ụ" ],
 		'is' => [ "Á", "Ð", "É", "Í", "Ó", "Ú", "Ý", "Þ", "Æ", "Ö", "Å" ],
 		'it' => [],
 		'ka' => [],
 		'kk' => [ "Ү", "І" ],
 		'kl' => [ "Æ", "Ø", "Å" ],
 		'km' => [
 			"រ", "ឫ", "ឬ", "ល", "ឭ", "ឮ", "\u{17BB}\u{17C6}",
 			"\u{17C6}", "\u{17B6}\u{17C6}", "\u{17C7}",
 			"\u{17B7}\u{17C7}", "\u{17BB}\u{17C7}",
 			"\u{17C1}\u{17C7}", "\u{17C4}\u{17C7}",
 		],
 		'kn' => [ "\u{0C81}", "\u{0C83}", "\u{0CF1}", "\u{0CF2}" ],
 		'kok' => [ "\u{0902}", "\u{0903}", "ळ", "क्ष" ],
 		'ku' => [ "Ç", "Ê", "Î", "Ş", "Û" ], // not in libicu
 		'ky' => [ "Ё" ],
 		'la' => [], // not in libicu
 		'lb' => [],
 		'lkt' => [ 'Č', 'Ǧ', 'Ȟ', 'Š', 'Ž' ],
 		'ln' => [ 'Ɛ' ],
 		'lo' => [],
 		'lt' => [ "Č", "Š", "Ž" ],
 		'lv' => [ "Č", "Ģ", "Ķ", "Ļ", "Ņ", "Š", "Ž" ],
 		'mk' => [ "Ѓ", "Ќ" ],
 		'ml' => [],
 		'mn' => [],
 		'mo' => [ "Ă", "Â", "Î", "Ș", "Ț" ], // not in libicu
 		'mr' => [ "\u{0902}", "\u{0903}", "ळ", "क्ष", "ज्ञ" ],
 		'ms' => [],
 		'mt' => [ "Ċ", "Ġ", "Għ", "Ħ", "Ż" ],
 		'nb' => [ "Æ", "Ø", "Å" ],
 		'ne' => [],
 		'nl' => [],
 		'nn' => [ "Æ", "Ø", "Å" ],
 		'no' => [ "Æ", "Ø", "Å" ], // not in libicu. You should probably use nb or nn instead.
 		'oc' => [], // not in libicu
 		'om' => [ 'Ch', 'Dh', 'Kh', 'Ny', 'Ph', 'Sh' ],
 		'or' => [ "\u{0B01}", "\u{0B02}", "\u{0B03}", "କ୍ଷ" ],
 		'pa' => [ "\u{0A4D}" ],
 		'pl' => [ "Ą", "Ć", "Ę", "Ł", "Ń", "Ó", "Ś", "Ź", "Ż" ],
 		'pt' => [],
 		'rm' => [], // not in libicu
 		'ro' => [ "Ă", "Â", "Î", "Ș", "Ț" ],
 		'ru' => [],
 		'rup' => [ "Ă", "Â", "Î", "Ľ", "Ń", "Ș", "Ț" ], // not in libicu
 		'sco' => [],
 		'se' => [
 			'Á', 'Č', 'Ʒ', 'Ǯ', 'Đ', 'Ǧ', 'Ǥ', 'Ǩ', 'Ŋ',
 			'Š', 'Ŧ', 'Ž', 'Ø', 'Æ', 'Ȧ', 'Ä', 'Ö'
 		],
 		'si' => [ "\u{0D82}", "\u{0D83}", "\u{0DA4}" ],
 		'sk' => [ "Ä", "Č", "Ch", "Ô", "Š", "Ž" ],
 		'sl' => [ "Č", "Š", "Ž" ],
 		'smn' => [ "Á", "Č", "Đ", "Ŋ", "Š", "Ŧ", "Ž", "Æ", "Ø", "Å", "Ä", "Ö" ],
 		'sq' => [ "Ç", "Dh", "Ë", "Gj", "Ll", "Nj", "Rr", "Sh", "Th", "Xh", "Zh" ],
 		'sr' => [],
 		'sr-Latn' => [ "Č", "Ć", "Dž", "Đ", "Lj", "Nj", "Š", "Ž" ],
 		'sv' => [ "Å", "Ä", "Ö" ],
 		'sv@collation=standard' => [ "Å", "Ä", "Ö" ],
 		'sw' => [],
 		'ta' => [
 			"\u{0B82}", "ஃ", "க்ஷ", "க்", "ங்", "ச்", "ஞ்", "ட்", "ண்", "த்", "ந்",
 			"ப்", "ம்", "ய்", "ர்", "ல்", "வ்", "ழ்", "ள்", "ற்", "ன்", "ஜ்", "ஶ்", "ஷ்",
 			"ஸ்", "ஹ்", "க்ஷ்"
 		],
 		'te' => [ "\u{0C01}", "\u{0C02}", "\u{0C03}" ],
 		'th' => [ "ฯ", "\u{0E46}", "\u{0E4D}", "\u{0E3A}" ],
 		'tk' => [ "Ç", "Ä", "Ž", "Ň", "Ö", "Ş", "Ü", "Ý" ],
 		'tl' => [ "Ñ", "Ng" ], // not in libicu
 		'to' => [ "Ng", "ʻ" ],
 		'tr' => [ "Ç", "Ğ", "İ", "Ö", "Ş", "Ü" ],
 		'-tr' => [ "ı" ],
 		'tt' => [ "Ә", "Ө", "Ү", "Җ", "Ң", "Һ" ], // not in libicu
 		'uk' => [ "Ґ", "Ь" ],
 		'uz' => [ "Ch", "G'", "Ng", "O'", "Sh" ], // not in libicu
 		'vi' => [ "Ă", "Â", "Đ", "Ê", "Ô", "Ơ", "Ư" ],
 		'vo' => [ "Ä", "Ö", "Ü" ],
 		'yi' => [
 			"\u{05D1}\u{05BF}", "\u{05DB}\u{05BC}", "\u{05E4}\u{05BC}",
 			"\u{05E9}\u{05C2}", "\u{05EA}\u{05BC}"
 		],
 		'yo' => [ "Ẹ", "Gb", "Ọ", "Ṣ" ],
 		'zu' => [],
 	];

 	/**
 	 * @param LanguageFactory $languageFactory
 	 * @param string $locale
 	 */
 	public function __construct(
 		LanguageFactory $languageFactory,
 		$locale
 	) {
 		$this->locale = $locale;
 		// Drop everything after the '@' in locale's name
 		$localeParts = explode( '@', $locale );
 		$this->digitTransformLanguage = $languageFactory->getLanguage( $locale === 'root' ? 'en' : $localeParts[0] );

 		$mainCollator = Collator::create( $locale );
 		if ( !$mainCollator ) {
 			throw new InvalidArgumentException( "Invalid ICU locale specified for collation: $locale" );
 		}
 		$this->mainCollator = $mainCollator;

 		// @phan-suppress-next-line PhanPossiblyNullTypeMismatchProperty successed before, no null check needed
 		$this->primaryCollator = Collator::create( $locale );
 		$this->primaryCollator->setStrength( Collator::PRIMARY );

 		// If the special suffix for numeric collation is present, turn on numeric collation.
 		if ( str_ends_with( $locale, '-u-kn' ) ) {
 			$this->useNumericCollation = true;
 			// Strip off the special suffix so it doesn't trip up fetchFirstLetterData().
 			$this->locale = substr( $this->locale, 0, -5 );
 			$this->mainCollator->setAttribute( Collator::NUMERIC_COLLATION, Collator::ON );
 			$this->primaryCollator->setAttribute( Collator::NUMERIC_COLLATION, Collator::ON );
 		}
 	}

 	public function getSortKey( $string ) {
 		return $this->mainCollator->getSortKey( $string );
 	}

 	public function getFirstLetter( $string ) {
 		$string = strval( $string );
 		if ( $string === '' ) {
 			return '';
 		}

 		$firstChar = mb_substr( $string, 0, 1, 'UTF-8' );

 		// If the first character is a CJK character, just return that character.
 		if ( ord( $firstChar ) > 0x7f && self::isCjk( mb_ord( $firstChar ) ) ) {
 			return $firstChar;
 		}

 		$sortKey = $this->getPrimarySortKey( $string );
 		$data = $this->getFirstLetterData();
 		$keys = $data['keys'];
 		$letters = $data['chars'];

 		// Do a binary search to find the correct letter to sort under
 		$min = ArrayUtils::findLowerBound(
 			static function ( $index ) use ( $keys ) {
 				return $keys[$index];
 			},
 			count( $keys ),
 			'strcmp',
 			$sortKey );

 		if ( $min === false ) {
 			// Before the first letter
 			return '';
 		}

 		$sortLetter = $letters[$min];

 		if ( $this->useNumericCollation ) {
 			// If the sort letter is a number, return '0–9' (or localized equivalent).
 			// ASCII value of 0 is 48. ASCII value of 9 is 57.
 			// Note that this also applies to non-Arabic numerals since they are
 			// mapped to Arabic numeral sort letters. For example, ২ sorts as 2.
 			if ( ord( $sortLetter ) >= 48 && ord( $sortLetter ) <= 57 ) {
 				$sortLetter = wfMessage( 'category-header-numerals' )->numParams( 0, 9 )->text();
 			}
 		}
 		return $sortLetter;
 	}

 	private function getPrimarySortKey( $string ) {
 		return $this->primaryCollator->getSortKey( $string );
 	}

 	/**
 	 * @since 1.16.3
 	 * @return array
 	 */
 	private function getFirstLetterData() {
 		if ( $this->firstLetterData === null ) {
 			$cache = MediaWikiServices::getInstance()->getObjectCacheFactory()
 				->getLocalServerInstance( CACHE_ANYTHING );
 			$cacheKey = $cache->makeKey(
 				'first-letters',
 				static::class,
 				$this->locale,
 				$this->digitTransformLanguage->getCode(),
 				INTL_ICU_VERSION,
 				self::FIRST_LETTER_VERSION
 			);
 			$this->firstLetterData = $cache->getWithSetCallback( $cacheKey, $cache::TTL_WEEK, function () {
 				return $this->fetchFirstLetterData();
 			} );
 		}
 		return $this->firstLetterData;
 	}

 	/**
 	 * @return array
 	 */
 	private function fetchFirstLetterData() {
 		// Generate data from serialized data file
 		if ( isset( self::TAILORING_FIRST_LETTERS[$this->locale] ) ) {
 			$letters = require __DIR__ . "/data/first-letters-root.php";
 			// Append additional characters
 			$letters = array_merge( $letters, self::TAILORING_FIRST_LETTERS[$this->locale] );
 			// Remove unnecessary ones, if any
 			if ( isset( self::TAILORING_FIRST_LETTERS['-' . $this->locale] ) ) {
 				$letters = array_diff( $letters, self::TAILORING_FIRST_LETTERS['-' . $this->locale] );
 			}
 			// Apply digit transforms
 			$digits = [ '0', '1', '2', '3', '4', '5', '6', '7', '8', '9' ];
 			$letters = array_diff( $letters, $digits );
 			foreach ( $digits as $digit ) {
 				$letters[] = $this->digitTransformLanguage->formatNumNoSeparators( $digit );
 			}
 		} elseif ( $this->locale === 'root' ) {
 			$letters = require __DIR__ . "/data/first-letters-root.php";
 		} else {
 			throw new RuntimeException( "MediaWiki does not support ICU locale " .
 				"\"{$this->locale}\"" );
 		}

 		/* Sort the letters.
 		 *
 		 * It's impossible to have the precompiled data file properly sorted,
 		 * because the sort order changes depending on ICU version. If the
 		 * array is not properly sorted, the binary search will return random
 		 * results.
 		 *
 		 * We also take this opportunity to remove primary collisions.
 		 */
 		$letterMap = [];
 		foreach ( $letters as $letter ) {
 			$key = $this->getPrimarySortKey( $letter );
 			if ( isset( $letterMap[$key] ) ) {
 				// Primary collision (two characters with the same sort position).
 				// Keep whichever one sorts first in the main collator.
 				$comp = $this->mainCollator->compare( $letter, $letterMap[$key] );
 				wfDebug( "Primary collision '$letter' '{$letterMap[$key]}' (comparison: $comp)" );
 				// If that also has a collision, use codepoint as a tiebreaker.
 				if ( $comp === 0 ) {
 					$comp = mb_ord( $letter ) <=> mb_ord( $letterMap[$key] );
 				}
 				if ( $comp < 0 ) {
 					$letterMap[$key] = $letter;
 				}
 			} else {
 				$letterMap[$key] = $letter;
 			}
 		}
 		ksort( $letterMap, SORT_STRING );

 		/* Remove duplicate prefixes. Basically, if something has a sortkey
 		 * which is a prefix of some other sortkey, then it is an
 		 * expansion and probably should not be considered a section
 		 * header.
 		 *
 		 * For example, 'þ' is sometimes sorted as if it is the letters
 		 * 'th'. Other times it is its own primary element. Another
 		 * example is '₨'. Sometimes it's a currency symbol. Sometimes it
 		 * is an 'R' followed by an 's'.
 		 *
 		 * Additionally, an expanded element should always sort directly
 		 * after its first element due to the way sortkeys work.
 		 *
 		 * UCA sortkey elements are of variable length, but no collation
 		 * element should be a prefix of some other element, so I think
 		 * this is safe. See:
 		 * - https://unicode-org.github.io/icu-docs/design/collation/ICU_collation_design.htm
 		 * - https://icu.unicode.org/design/collation/uca-weight-allocation
 		 *
 		 * Additionally, there is something called primary compression to
 		 * worry about. Basically, if you have two primary elements that
 		 * are more than one byte and both start with the same byte, then
 		 * the first byte is dropped on the second primary. Additionally,
 		 * either \x03 or \xFF may be added to mean that the next primary
 		 * does not start with the first byte of the first primary.
 		 *
 		 * This shouldn't matter much, as the first primary is not
 		 * changed, and that is what we are comparing against.
 		 *
 		 * tl;dr: This makes some assumptions about how ICU implements
 		 * collations. It seems incredibly unlikely these assumptions
 		 * will change, but nonetheless they are assumptions.
 		 */

 		$prev = '';
 		$duplicatePrefixes = [];
 		foreach ( $letterMap as $key => $value ) {
 			// Due to the fact the array is sorted, we only have
 			// to compare with the element directly previous
 			// to the current element (skipping expansions).
 			// An element "X" will always sort directly
 			// before "XZ" (Unless we have "XY", but we
 			// do not update $prev in that case).
 			if ( $prev !== '' && str_starts_with( $key, $prev ) ) {
 				$duplicatePrefixes[] = $key;
 				// If this is an expansion, we don't want to
 				// compare the next element to this element,
 				// but to what is currently $prev
 				continue;
 			}
 			$prev = $key;
 		}
 		foreach ( $duplicatePrefixes as $badKey ) {
 			wfDebug( "Removing '{$letterMap[$badKey]}' from first letters." );
 			unset( $letterMap[$badKey] );
 			// This code assumes that unsetting does not change sort order.
 		}
 		return [
 			'chars' => array_values( $letterMap ),
 			'keys' => array_keys( $letterMap ),
 		];
 	}

 	/**
 	 * Test if a code point is a CJK (Chinese, Japanese, Korean) character
 	 * @param int $codepoint
 	 * @return bool
 	 * @since 1.16.3
 	 */
 	public static function isCjk( $codepoint ) {
 		foreach ( self::CJK_BLOCKS as $block ) {
 			if ( $codepoint >= $block[0] && $codepoint <= $block[1] ) {
 				return true;
 			}
 		}
 		return false;
 	}
 }
	<?php
	/**
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or
	* (at your option) any later version.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License along
	* with this program; if not, write to the Free Software Foundation, Inc.,
	* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
	* http://www.gnu.org/copyleft/gpl.html
	*
	* @file
	*/

	use MediaWiki\Languages\LanguageFactory;
	use MediaWiki\MediaWikiServices;

	/**
	* @since 1.16.3
	*/
	class IcuCollation extends Collation {
	private const FIRST_LETTER_VERSION = 4;

	/** @var Collator */
	private $primaryCollator;

	/** @var Collator */
	private $mainCollator;

	/** @var string */
	private $locale;

	/** @var Language */
	protected $digitTransformLanguage;

	/** @var bool */
	private $useNumericCollation = false;

	/** @var array */
	private $firstLetterData;

	/**
	* Unified CJK blocks.
	*
	* The same definition of a CJK block must be used for both Collation and
	* generateCollationData.php. These blocks are omitted from the first
	* letter data, as an optimisation measure and because the default UCA table
	* is pretty useless for sorting Chinese text anyway. Japanese and Korean
	* blocks are not included here, because they are smaller and more useful.
	*/
	private const CJK_BLOCKS = [
	[ 0x2E80, 0x2EFF ], // CJK Radicals Supplement
	[ 0x2F00, 0x2FDF ], // Kangxi Radicals
	[ 0x2FF0, 0x2FFF ], // Ideographic Description Characters
	[ 0x3000, 0x303F ], // CJK Symbols and Punctuation
	[ 0x31C0, 0x31EF ], // CJK Strokes
	[ 0x3200, 0x32FF ], // Enclosed CJK Letters and Months
	[ 0x3300, 0x33FF ], // CJK Compatibility
	[ 0x3400, 0x4DBF ], // CJK Unified Ideographs Extension A
	[ 0x4E00, 0x9FFF ], // CJK Unified Ideographs
	[ 0xF900, 0xFAFF ], // CJK Compatibility Ideographs
	[ 0xFE30, 0xFE4F ], // CJK Compatibility Forms
	[ 0x20000, 0x2A6DF ], // CJK Unified Ideographs Extension B
	[ 0x2A700, 0x2B73F ], // CJK Unified Ideographs Extension C
	[ 0x2B740, 0x2B81F ], // CJK Unified Ideographs Extension D
	[ 0x2F800, 0x2FA1F ], // CJK Compatibility Ideographs Supplement
	];

	/**
	* Additional characters (or character groups) to be considered separate
	* letters for given languages, or to be removed from the list of such
	* letters (denoted by keys starting with '-').
	*
	* These are additions to (or subtractions from) the data stored in the
	* first-letters-root.php data file (which among others includes full basic
	* Latin, Cyrillic and Greek alphabets).
	*
	* "Separate letter" is a letter that would have a separate heading/section
	* for it in a dictionary or a phone book in this language. This data isn't
	* used for sorting (the ICU library handles that), only for deciding which
	* characters (or character groups) to use as headings.
	*
	* Initially generated based on the primary level of Unicode collation
	* tailorings available at http://developer.mimer.com/charts/tailorings.htm ,
	* later modified.
	*
	* Empty arrays are intended; this signifies that the data for the language is
	* available and that there are, in fact, no additional letters to consider.
	*/
	private const TAILORING_FIRST_LETTERS = [
	'af' => [],
	'am' => [],
	'ar' => [],
	'as' => [ "\u{0982}", "\u{0981}", "\u{0983}", "\u{09CE}", "ক্ষ " ],
	'ast' => [ "Ch", "Ll", "Ñ" ], // not in libicu
	'az' => [ "Ç", "Ə", "Ğ", "İ", "Ö", "Ş", "Ü" ],
	'be' => [ "Ё" ],
	'be-tarask' => [ "Ё" ],
	'bg' => [],
	'bn' => [ 'ং', 'ঃ', 'ঁ' ],
	'bn@collation=traditional' => [
	'ং', 'ঃ', 'ঁ', 'ক্', 'খ্', 'গ্', 'ঘ্', 'ঙ্', 'চ্', 'ছ্', 'জ্', 'ঝ্',
	'ঞ্', 'ট্', 'ঠ্', 'ড্', 'ঢ্', 'ণ্', 'ৎ', 'থ্', 'দ্', 'ধ্', 'ন্', 'প্',
	'ফ্', 'ব্', 'ভ্', 'ম্', 'য্', 'র্', 'ৰ্', 'ল্', 'ৱ্', 'শ্', 'ষ্', 'স্', 'হ্'
	],
	'bo' => [],
	'br' => [ "Ch", "C'h" ],
	'bs' => [ "Č", "Ć", "Dž", "Đ", "Lj", "Nj", "Š", "Ž" ],
	'bs-Cyrl' => [],
	'ca' => [],
	'chr' => [],
	'co' => [], // not in libicu
	'cs' => [ "Č", "Ch", "Ř", "Š", "Ž" ],
	'cy' => [ "Ch", "Dd", "Ff", "Ng", "Ll", "Ph", "Rh", "Th" ],
	'da' => [ "Æ", "Ø", "Å" ],
	'de' => [],
	'de-AT@collation=phonebook' => [ 'ä', 'ö', 'ü', 'ß' ],
	'dsb' => [ "Č", "Ć", "Dź", "Ě", "Ch", "Ł", "Ń", "Ŕ", "Š", "Ś", "Ž", "Ź" ],
	'ee' => [ "Dz", "Ɖ", "Ɛ", "Ƒ", "Gb", "Ɣ", "Kp", "Ny", "Ŋ", "Ɔ", "Ts", "Ʋ" ],
	'el' => [],
	'en' => [],
	'eo' => [ "Ĉ", "Ĝ", "Ĥ", "Ĵ", "Ŝ", "Ŭ" ],
	'es' => [ "Ñ" ],
	'et' => [ "Š", "Ž", "Õ", "Ä", "Ö", "Ü" ],
	'eu' => [ "Ñ" ], // not in libicu
	'fa' => [
	// RTL, let's put each letter on a new line
	"آ",
	"ء",
	"ه",
	"ا",
	"و"
	],
	'fi' => [ "Å", "Ä", "Ö" ],
	'fil' => [ "Ñ", "Ng" ],
	'fo' => [ "Á", "Ð", "Í", "Ó", "Ú", "Ý", "Æ", "Ø", "Å" ],
	'fr' => [],
	'fr-CA' => [], // fr-CA sorts accents slightly different from fr.
	'fur' => [ "À", "Á", "Â", "È", "Ì", "Ò", "Ù" ], // not in libicu
	'fy' => [], // not in libicu
	'ga' => [],
	'gd' => [], // not in libicu
	'gl' => [ "Ch", "Ll", "Ñ" ],
	'gu' => [ "\u{0A82}", "\u{0A83}", "\u{0A81}", "\u{0AB3}" ],
	'ha' => [ 'Ɓ', 'Ɗ', 'Ƙ', 'Sh', 'Ts', 'Ƴ' ],
	'haw' => [ 'ʻ' ],
	'he' => [],
	'hi' => [ "\u{0902}", "\u{0903}" ],
	'hr' => [ "Č", "Ć", "Dž", "Đ", "Lj", "Nj", "Š", "Ž" ],
	'hsb' => [ "Č", "Dź", "Ě", "Ch", "Ł", "Ń", "Ř", "Š", "Ć", "Ž" ],
	'hu' => [ "Cs", "Dz", "Dzs", "Gy", "Ly", "Ny", "Ö", "Sz", "Ty", "Ü", "Zs" ],
	'hy' => [ "և" ],
	'id' => [],
	'ig' => [ "Ch", "Gb", "Gh", "Gw", "Ị", "Kp", "Kw", "Ṅ", "Nw", "Ny", "Ọ", "Sh", "Ụ" ],
	'is' => [ "Á", "Ð", "É", "Í", "Ó", "Ú", "Ý", "Þ", "Æ", "Ö", "Å" ],
	'it' => [],
	'ka' => [],
	'kk' => [ "Ү", "І" ],
	'kl' => [ "Æ", "Ø", "Å" ],
	'km' => [
	"រ", "ឫ", "ឬ", "ល", "ឭ", "ឮ", "\u{17BB}\u{17C6}",
	"\u{17C6}", "\u{17B6}\u{17C6}", "\u{17C7}",
	"\u{17B7}\u{17C7}", "\u{17BB}\u{17C7}",
	"\u{17C1}\u{17C7}", "\u{17C4}\u{17C7}",
	],
	'kn' => [ "\u{0C81}", "\u{0C83}", "\u{0CF1}", "\u{0CF2}" ],
	'kok' => [ "\u{0902}", "\u{0903}", "ळ", "क्ष" ],
	'ku' => [ "Ç", "Ê", "Î", "Ş", "Û" ], // not in libicu
	'ky' => [ "Ё" ],
	'la' => [], // not in libicu
	'lb' => [],
	'lkt' => [ 'Č', 'Ǧ', 'Ȟ', 'Š', 'Ž' ],
	'ln' => [ 'Ɛ' ],
	'lo' => [],
	'lt' => [ "Č", "Š", "Ž" ],
	'lv' => [ "Č", "Ģ", "Ķ", "Ļ", "Ņ", "Š", "Ž" ],
	'mk' => [ "Ѓ", "Ќ" ],
	'ml' => [],
	'mn' => [],
	'mo' => [ "Ă", "Â", "Î", "Ș", "Ț" ], // not in libicu
	'mr' => [ "\u{0902}", "\u{0903}", "ळ", "क्ष", "ज्ञ" ],
	'ms' => [],
	'mt' => [ "Ċ", "Ġ", "Għ", "Ħ", "Ż" ],
	'nb' => [ "Æ", "Ø", "Å" ],
	'ne' => [],
	'nl' => [],
	'nn' => [ "Æ", "Ø", "Å" ],
	'no' => [ "Æ", "Ø", "Å" ], // not in libicu. You should probably use nb or nn instead.
	'oc' => [], // not in libicu
	'om' => [ 'Ch', 'Dh', 'Kh', 'Ny', 'Ph', 'Sh' ],
	'or' => [ "\u{0B01}", "\u{0B02}", "\u{0B03}", "କ୍ଷ" ],
	'pa' => [ "\u{0A4D}" ],
	'pl' => [ "Ą", "Ć", "Ę", "Ł", "Ń", "Ó", "Ś", "Ź", "Ż" ],
	'pt' => [],
	'rm' => [], // not in libicu
	'ro' => [ "Ă", "Â", "Î", "Ș", "Ț" ],
	'ru' => [],
	'rup' => [ "Ă", "Â", "Î", "Ľ", "Ń", "Ș", "Ț" ], // not in libicu
	'sco' => [],
	'se' => [
	'Á', 'Č', 'Ʒ', 'Ǯ', 'Đ', 'Ǧ', 'Ǥ', 'Ǩ', 'Ŋ',
	'Š', 'Ŧ', 'Ž', 'Ø', 'Æ', 'Ȧ', 'Ä', 'Ö'
	],
	'si' => [ "\u{0D82}", "\u{0D83}", "\u{0DA4}" ],
	'sk' => [ "Ä", "Č", "Ch", "Ô", "Š", "Ž" ],
	'sl' => [ "Č", "Š", "Ž" ],
	'smn' => [ "Á", "Č", "Đ", "Ŋ", "Š", "Ŧ", "Ž", "Æ", "Ø", "Å", "Ä", "Ö" ],
	'sq' => [ "Ç", "Dh", "Ë", "Gj", "Ll", "Nj", "Rr", "Sh", "Th", "Xh", "Zh" ],
	'sr' => [],
	'sr-Latn' => [ "Č", "Ć", "Dž", "Đ", "Lj", "Nj", "Š", "Ž" ],
	'sv' => [ "Å", "Ä", "Ö" ],
	'sv@collation=standard' => [ "Å", "Ä", "Ö" ],
	'sw' => [],
	'ta' => [
	"\u{0B82}", "ஃ", "க்ஷ", "க்", "ங்", "ச்", "ஞ்", "ட்", "ண்", "த்", "ந்",
	"ப்", "ம்", "ய்", "ர்", "ல்", "வ்", "ழ்", "ள்", "ற்", "ன்", "ஜ்", "ஶ்", "ஷ்",
	"ஸ்", "ஹ்", "க்ஷ்"
	],
	'te' => [ "\u{0C01}", "\u{0C02}", "\u{0C03}" ],
	'th' => [ "ฯ", "\u{0E46}", "\u{0E4D}", "\u{0E3A}" ],
	'tk' => [ "Ç", "Ä", "Ž", "Ň", "Ö", "Ş", "Ü", "Ý" ],
	'tl' => [ "Ñ", "Ng" ], // not in libicu
	'to' => [ "Ng", "ʻ" ],
	'tr' => [ "Ç", "Ğ", "İ", "Ö", "Ş", "Ü" ],
	'-tr' => [ "ı" ],
	'tt' => [ "Ә", "Ө", "Ү", "Җ", "Ң", "Һ" ], // not in libicu
	'uk' => [ "Ґ", "Ь" ],
	'uz' => [ "Ch", "G'", "Ng", "O'", "Sh" ], // not in libicu
	'vi' => [ "Ă", "Â", "Đ", "Ê", "Ô", "Ơ", "Ư" ],
	'vo' => [ "Ä", "Ö", "Ü" ],
	'yi' => [
	"\u{05D1}\u{05BF}", "\u{05DB}\u{05BC}", "\u{05E4}\u{05BC}",
	"\u{05E9}\u{05C2}", "\u{05EA}\u{05BC}"
	],
	'yo' => [ "Ẹ", "Gb", "Ọ", "Ṣ" ],
	'zu' => [],
	];

	/**
	* @param LanguageFactory $languageFactory
	* @param string $locale
	*/
	public function __construct(
	LanguageFactory $languageFactory,
	$locale
	) {
	$this->locale = $locale;
	// Drop everything after the '@' in locale's name
	$localeParts = explode( '@', $locale );
	$this->digitTransformLanguage = $languageFactory->getLanguage( $locale === 'root' ? 'en' : $localeParts[0] );

	$mainCollator = Collator::create( $locale );
	if ( !$mainCollator ) {
	throw new InvalidArgumentException( "Invalid ICU locale specified for collation: $locale" );
	}
	$this->mainCollator = $mainCollator;

	// @phan-suppress-next-line PhanPossiblyNullTypeMismatchProperty successed before, no null check needed
	$this->primaryCollator = Collator::create( $locale );
	$this->primaryCollator->setStrength( Collator::PRIMARY );

	// If the special suffix for numeric collation is present, turn on numeric collation.
	if ( str_ends_with( $locale, '-u-kn' ) ) {
	$this->useNumericCollation = true;
	// Strip off the special suffix so it doesn't trip up fetchFirstLetterData().
	$this->locale = substr( $this->locale, 0, -5 );
	$this->mainCollator->setAttribute( Collator::NUMERIC_COLLATION, Collator::ON );
	$this->primaryCollator->setAttribute( Collator::NUMERIC_COLLATION, Collator::ON );
	}
	}

	public function getSortKey( $string ) {
	return $this->mainCollator->getSortKey( $string );
	}

	public function getFirstLetter( $string ) {
	$string = strval( $string );
	if ( $string === '' ) {
	return '';
	}

	$firstChar = mb_substr( $string, 0, 1, 'UTF-8' );

	// If the first character is a CJK character, just return that character.
	if ( ord( $firstChar ) > 0x7f && self::isCjk( mb_ord( $firstChar ) ) ) {
	return $firstChar;
	}

	$sortKey = $this->getPrimarySortKey( $string );
	$data = $this->getFirstLetterData();
	$keys = $data['keys'];
	$letters = $data['chars'];

	// Do a binary search to find the correct letter to sort under
	$min = ArrayUtils::findLowerBound(
	static function ( $index ) use ( $keys ) {
	return $keys[$index];
	},
	count( $keys ),
	'strcmp',
	$sortKey );

	if ( $min === false ) {
	// Before the first letter
	return '';
	}

	$sortLetter = $letters[$min];

	if ( $this->useNumericCollation ) {
	// If the sort letter is a number, return '0–9' (or localized equivalent).
	// ASCII value of 0 is 48. ASCII value of 9 is 57.
	// Note that this also applies to non-Arabic numerals since they are
	// mapped to Arabic numeral sort letters. For example, ২ sorts as 2.
	if ( ord( $sortLetter ) >= 48 && ord( $sortLetter ) <= 57 ) {
	$sortLetter = wfMessage( 'category-header-numerals' )->numParams( 0, 9 )->text();
	}
	}
	return $sortLetter;
	}

	private function getPrimarySortKey( $string ) {
	return $this->primaryCollator->getSortKey( $string );
	}

	/**
	* @since 1.16.3
	* @return array
	*/
	private function getFirstLetterData() {
	if ( $this->firstLetterData === null ) {
	$cache = MediaWikiServices::getInstance()->getObjectCacheFactory()
	->getLocalServerInstance( CACHE_ANYTHING );
	$cacheKey = $cache->makeKey(
	'first-letters',
	static::class,
	$this->locale,
	$this->digitTransformLanguage->getCode(),
	INTL_ICU_VERSION,
	self::FIRST_LETTER_VERSION
	);
	$this->firstLetterData = $cache->getWithSetCallback( $cacheKey, $cache::TTL_WEEK, function () {
	return $this->fetchFirstLetterData();
	} );
	}
	return $this->firstLetterData;
	}

	/**
	* @return array
	*/
	private function fetchFirstLetterData() {
	// Generate data from serialized data file
	if ( isset( self::TAILORING_FIRST_LETTERS[$this->locale] ) ) {
	$letters = require __DIR__ . "/data/first-letters-root.php";
	// Append additional characters
	$letters = array_merge( $letters, self::TAILORING_FIRST_LETTERS[$this->locale] );
	// Remove unnecessary ones, if any
	if ( isset( self::TAILORING_FIRST_LETTERS['-' . $this->locale] ) ) {
	$letters = array_diff( $letters, self::TAILORING_FIRST_LETTERS['-' . $this->locale] );
	}
	// Apply digit transforms
	$digits = [ '0', '1', '2', '3', '4', '5', '6', '7', '8', '9' ];
	$letters = array_diff( $letters, $digits );
	foreach ( $digits as $digit ) {
	$letters[] = $this->digitTransformLanguage->formatNumNoSeparators( $digit );
	}
	} elseif ( $this->locale === 'root' ) {
	$letters = require __DIR__ . "/data/first-letters-root.php";
	} else {
	throw new RuntimeException( "MediaWiki does not support ICU locale " .
	"\"{$this->locale}\"" );
	}

	/* Sort the letters.
	*
	* It's impossible to have the precompiled data file properly sorted,
	* because the sort order changes depending on ICU version. If the
	* array is not properly sorted, the binary search will return random
	* results.
	*
	* We also take this opportunity to remove primary collisions.
	*/
	$letterMap = [];
	foreach ( $letters as $letter ) {
	$key = $this->getPrimarySortKey( $letter );
	if ( isset( $letterMap[$key] ) ) {
	// Primary collision (two characters with the same sort position).
	// Keep whichever one sorts first in the main collator.
	$comp = $this->mainCollator->compare( $letter, $letterMap[$key] );
	wfDebug( "Primary collision '$letter' '{$letterMap[$key]}' (comparison: $comp)" );
	// If that also has a collision, use codepoint as a tiebreaker.
	if ( $comp === 0 ) {
	$comp = mb_ord( $letter ) <=> mb_ord( $letterMap[$key] );
	}
	if ( $comp < 0 ) {
	$letterMap[$key] = $letter;
	}
	} else {
	$letterMap[$key] = $letter;
	}
	}
	ksort( $letterMap, SORT_STRING );

	/* Remove duplicate prefixes. Basically, if something has a sortkey
	* which is a prefix of some other sortkey, then it is an
	* expansion and probably should not be considered a section
	* header.
	*
	* For example, 'þ' is sometimes sorted as if it is the letters
	* 'th'. Other times it is its own primary element. Another
	* example is '₨'. Sometimes it's a currency symbol. Sometimes it
	* is an 'R' followed by an 's'.
	*
	* Additionally, an expanded element should always sort directly
	* after its first element due to the way sortkeys work.
	*
	* UCA sortkey elements are of variable length, but no collation
	* element should be a prefix of some other element, so I think
	* this is safe. See:
	* - https://unicode-org.github.io/icu-docs/design/collation/ICU_collation_design.htm
	* - https://icu.unicode.org/design/collation/uca-weight-allocation
	*
	* Additionally, there is something called primary compression to
	* worry about. Basically, if you have two primary elements that
	* are more than one byte and both start with the same byte, then
	* the first byte is dropped on the second primary. Additionally,
	* either \x03 or \xFF may be added to mean that the next primary
	* does not start with the first byte of the first primary.
	*
	* This shouldn't matter much, as the first primary is not
	* changed, and that is what we are comparing against.
	*
	* tl;dr: This makes some assumptions about how ICU implements
	* collations. It seems incredibly unlikely these assumptions
	* will change, but nonetheless they are assumptions.
	*/

	$prev = '';
	$duplicatePrefixes = [];
	foreach ( $letterMap as $key => $value ) {
	// Due to the fact the array is sorted, we only have
	// to compare with the element directly previous
	// to the current element (skipping expansions).
	// An element "X" will always sort directly
	// before "XZ" (Unless we have "XY", but we
	// do not update $prev in that case).
	if ( $prev !== '' && str_starts_with( $key, $prev ) ) {
	$duplicatePrefixes[] = $key;
	// If this is an expansion, we don't want to
	// compare the next element to this element,
	// but to what is currently $prev
	continue;
	}
	$prev = $key;
	}
	foreach ( $duplicatePrefixes as $badKey ) {
	wfDebug( "Removing '{$letterMap[$badKey]}' from first letters." );
	unset( $letterMap[$badKey] );
	// This code assumes that unsetting does not change sort order.
	}
	return [
	'chars' => array_values( $letterMap ),
	'keys' => array_keys( $letterMap ),
	];
	}

	/**
	* Test if a code point is a CJK (Chinese, Japanese, Korean) character
	* @param int $codepoint
	* @return bool
	* @since 1.16.3
	*/
	public static function isCjk( $codepoint ) {
	foreach ( self::CJK_BLOCKS as $block ) {
	if ( $codepoint >= $block[0] && $codepoint <= $block[1] ) {
	return true;
	}
	}
	return false;
	}
	}