1 files changed, 222 insertions, 14 deletions

diff --git a/www/wiki/extensions/Translate/utils/ArrayFlattener.php b/www/wiki/extensions/Translate/utils/ArrayFlattener.php
index 8845ef1c..c5e61769 100644
--- a/www/wiki/extensions/Translate/utils/ArrayFlattener.php
+++ b/www/wiki/extensions/Translate/utils/ArrayFlattener.php
@@ -1,28 +1,43 @@
 <?php
 /**
- * Support for JSON message file format.
+ * Flattens message arrays for further processing. Supports parsing CLDR
+ * plural messages and converting them into MediaWiki's {{PLURAL}} syntax
+ * in a single message.
  *
  * @file
  * @author Niklas Laxström
- * @license GPL-2.0+
+ * @author Erik Moeller
+ * @license GPL-2.0-or-later
  * @since 2016.01
  */
 
 class ArrayFlattener {
 	protected $sep;
+	protected $parseCLDRPlurals;
 
-	public function __construct( $sep = '.' ) {
+	// For CLDR pluralization rules
+	protected static $pluralWords = [
+		'zero' => 1,
+		'one' => 1,
+		'many' => 1,
+		'few' => 1,
+		'other' => 1,
+		'two' => 1
+	];
+
+	public function __construct( $sep = '.', $parseCLDRPlurals = false ) {
 		$this->sep = $sep;
+		$this->parseCLDRPlurals = $parseCLDRPlurals;
 	}
 
 	/**
 	 * Flattens multidimensional array.
 	 *
-	 * @param array $unflat It's an array.
+	 * @param array $unflat Array of messages
 	 * @return array
 	 */
 	public function flatten( array $unflat ) {
-		$flat = array();
+		$flat = [];
 
 		foreach ( $unflat as $key => $value ) {
 			if ( !is_array( $value ) ) {
@@ -30,14 +45,21 @@ class ArrayFlattener {
 				continue;
 			}
 
-			// Placeholder for special plural processing
+			$plurals = false;
+			if ( $this->parseCLDRPlurals ) {
+				$plurals = $this->flattenCLDRPlurals( $value );
+			}
 
-			$temp = array();
-			foreach ( $value as $subKey => $subValue ) {
-				$newKey = "$key{$this->sep}$subKey";
-				$temp[$newKey] = $subValue;
+			if ( $this->parseCLDRPlurals && $plurals ) {
+				$flat[$key] = $plurals;
+			} else {
+				$temp = [];
+				foreach ( $value as $subKey => $subValue ) {
+					$newKey = "$key{$this->sep}$subKey";
+					$temp[$newKey] = $subValue;
+				}
+				$flat += $this->flatten( $temp );
 			}
-			$flat += $this->flatten( $temp );
 
 			// Can as well keep only one copy around.
 			unset( $unflat[$key] );
@@ -47,13 +69,82 @@ class ArrayFlattener {
 	}
 
 	/**
+	 * Flattens arrays that contain CLDR plural keywords into single values using
+	 * MediaWiki's plural syntax.
+	 *
+	 * @param array $messages Array of messages
+	 *
+	 * @throws MWException
+	 * @return bool|string
+	 */
+	public function flattenCLDRPlurals( $messages ) {
+		$pluralKeys = false;
+		$nonPluralKeys = false;
+		foreach ( $messages as $key => $value ) {
+			if ( is_array( $value ) ) {
+				// Plurals can only happen in the lowest level of the structure
+				return false;
+			}
+
+			// Check if we find any reserved plural keyword
+			if ( isset( self::$pluralWords[$key] ) ) {
+				$pluralKeys = true;
+			} else {
+				$nonPluralKeys = true;
+			}
+		}
+
+		// No plural keys at all, we can skip
+		if ( !$pluralKeys ) {
+			return false;
+		}
+
+		// Mixed plural keys with other keys, should not happen
+		if ( $nonPluralKeys ) {
+			$keys = implode( ', ', array_keys( $messages ) );
+			throw new MWException( "Reserved plural keywords mixed with other keys: $keys." );
+		}
+
+		$pls = '{{PLURAL';
+		foreach ( $messages as $key => $value ) {
+			if ( $key === 'other' ) {
+				continue;
+			}
+
+			$pls .= "|$key=$value";
+		}
+
+		// Put the "other" alternative last, without other= prefix.
+		$other = isset( $messages['other'] ) ? '|' . $messages['other'] : '';
+		$pls .= "$other}}";
+
+		return $pls;
+	}
+
+	/**
 	 * Performs the reverse operation of flatten.
 	 *
-	 * @param array $flat It's an array
+	 * @param array $flat Array of messages
 	 * @return array
 	 */
 	public function unflatten( $flat ) {
-		$unflat = array();
+		$unflat = [];
+
+		if ( $this->parseCLDRPlurals ) {
+			$unflattenedPlurals = [];
+			foreach ( $flat as $key => $value ) {
+				$plurals = false;
+				if ( !is_array( $value ) ) {
+					$plurals = $this->unflattenCLDRPlurals( $key, $value );
+				}
+				if ( $plurals ) {
+					$unflattenedPlurals += $plurals;
+				} else {
+					$unflattenedPlurals[$key] = $value;
+				}
+			}
+			$flat = $unflattenedPlurals;
+		}
 
 		foreach ( $flat as $key => $value ) {
 			$path = explode( $this->sep, $key );
@@ -67,7 +158,7 @@ class ArrayFlattener {
 				/// Extract the level and make sure it exists.
 				$level = array_shift( $path );
 				if ( !isset( $pointer[$level] ) ) {
-					$pointer[$level] = array();
+					$pointer[$level] = [];
 				}
 
 				/// Update the pointer to the new reference.
@@ -86,4 +177,121 @@ class ArrayFlattener {
 
 		return $unflat;
 	}
+
+	/**
+	 * Converts the MediaWiki plural syntax to array of CLDR style plurals
+	 *
+	 * @param string $key Message key prefix
+	 * @param string $message The plural string
+	 *
+	 * @return bool|array
+	 */
+	public function unflattenCLDRPlurals( $key, $message ) {
+		// Quick escape.
+		if ( strpos( $message, '{{PLURAL' ) === false ) {
+			return false;
+		}
+
+		/*
+		 * Replace all variables with placeholders. Possible source of bugs
+		 * if other characters that given below are used.
+		 */
+		$regex = '~\{[a-zA-Z_-]+}~';
+		$placeholders = [];
+		$match = [];
+
+		while ( preg_match( $regex, $message, $match ) ) {
+			$uniqkey = TranslateUtils::getPlaceholder();
+			$placeholders[$uniqkey] = $match[0];
+			$search = preg_quote( $match[0], '~' );
+			$message = preg_replace( "~$search~", $uniqkey, $message );
+		}
+
+		// Then replace (possible multiple) plural instances into placeholders.
+		$regex = '~\{\{PLURAL\|(.*?)}}~s';
+		$matches = [];
+		$match = [];
+
+		while ( preg_match( $regex, $message, $match ) ) {
+			$uniqkey = TranslateUtils::getPlaceholder();
+			$matches[$uniqkey] = $match;
+			$message = preg_replace( $regex, $uniqkey, $message, 1 );
+		}
+
+		// No plurals, should not happen.
+		if ( !count( $matches ) ) {
+			return false;
+		}
+
+		// The final array of alternative plurals forms.
+		$alts = [];
+
+		/*
+		 * Then loop trough each plural block and replacing the placeholders
+		 * to construct the alternatives. Produces invalid output if there is
+		 * multiple plural bocks which don't have the same set of keys.
+		 */
+		$pluralChoice = implode( '|', array_keys( self::$pluralWords ) );
+		$regex = "~($pluralChoice)\s*=\s*(.+)~s";
+		foreach ( $matches as $ph => $plu ) {
+			$forms = explode( '|', $plu[1] );
+
+			foreach ( $forms as $form ) {
+				if ( $form === '' ) {
+					continue;
+				}
+
+				$match = [];
+				if ( preg_match( $regex, $form, $match ) ) {
+					$formWord = "$key{$this->sep}{$match[1]}";
+					$value = $match[2];
+				} else {
+					$formWord = "$key{$this->sep}other";
+					$value = $form;
+				}
+
+				if ( !isset( $alts[$formWord] ) ) {
+					$alts[$formWord] = $message;
+				}
+
+				$string = $alts[$formWord];
+				$alts[$formWord] = str_replace( $ph, $value, $string );
+			}
+		}
+
+		// Replace other variables.
+		foreach ( $alts as &$value ) {
+			$value = str_replace( array_keys( $placeholders ), array_values( $placeholders ), $value );
+		}
+
+		if ( !isset( $alts["$key{$this->sep}other"] ) ) {
+			wfWarn( "Other not set for key $key" );
+		}
+
+		return $alts;
+	}
+
+	/**
+	 * Compares two strings for equal content, taking PLURAL expansion into account.
+	 *
+	 * @param string $a
+	 * @param string $b
+	 * @return bool Whether two strings are equal
+	 */
+	public function compareContent( $a, $b ) {
+		if ( !$this->parseCLDRPlurals ) {
+			return $a === $b;
+		}
+
+		$a2 = $this->unflattenCLDRPlurals( 'prefix', $a );
+		$b2 = $this->unflattenCLDRPlurals( 'prefix', $b );
+
+		// Fall back to regular comparison if parsing fails.
+		if ( $a2 === false || $b2 === false ) {
+			return $a === $b;
+		}
+
+		// Require key-value pairs to match, but ignore order and types (all should be strings).
+		return $a2 == $b2;
+	}
 }