<?php
/**
 * I18N: WP_Translation_File_MO class.
 *
 * @package WordPress
 * @subpackage I18N
 * @since 6.5.0
 */

/**
 * Class WP_Translation_File_MO.
 *
 * @since 6.5.0
 */
class WP_Translation_File_MO extends WP_Translation_File {
	/**
	 * Endian value.
	 *
	 * V for little endian, N for big endian, or false.
	 *
	 * Used for unpack().
	 *
	 * @since 6.5.0
	 * @var false|'V'|'N'
	 */
	protected $uint32 = false;

	/**
	 * The magic number of the GNU message catalog format.
	 *
	 * @since 6.5.0
	 * @var int
	 */
	const MAGIC_MARKER = 0x950412de;

	/**
	 * Detects endian and validates file.
	 *
	 * @since 6.5.0
	 *
	 * @param string $header File contents.
	 * @return false|'V'|'N' V for little endian, N for big endian, or false on failure.
	 */
	protected function detect_endian_and_validate_file( string $header ) {
		$big = unpack( 'N', $header );

		if ( false === $big ) {
			return false;
		}

		$big = reset( $big );

		if ( false === $big ) {
			return false;
		}

		$little = unpack( 'V', $header );

		if ( false === $little ) {
			return false;
		}

		$little = reset( $little );

		if ( false === $little ) {
			return false;
		}

		// Force cast to an integer as it can be a float on x86 systems. See https://core.trac.wordpress.org/ticket/60678.
		if ( (int) self::MAGIC_MARKER === $big ) {
			return 'N';
		}

		// Force cast to an integer as it can be a float on x86 systems. See https://core.trac.wordpress.org/ticket/60678.
		if ( (int) self::MAGIC_MARKER === $little ) {
			return 'V';
		}

		$this->error = 'Magic marker does not exist';
		return false;
	}

	/**
	 * Parses the file.
	 *
	 * @since 6.5.0
	 *
	 * @return bool True on success, false otherwise.
	 */
	protected function parse_file(): bool {
		$this->parsed = true;

		$file_contents = file_get_contents( $this->file ); // phpcs:ignore WordPress.WP.AlternativeFunctions.file_get_contents_file_get_contents

		if ( false === $file_contents ) {
			return false;
		}

		$file_length = strlen( $file_contents );

		if ( $file_length < 24 ) {
			$this->error = 'Invalid data';
			return false;
		}

		$this->uint32 = $this->detect_endian_and_validate_file( substr( $file_contents, 0, 4 ) );

		if ( false === $this->uint32 ) {
			return false;
		}

		$offsets = substr( $file_contents, 4, 24 );

		if ( false === $offsets ) {
			return false;
		}

		$offsets = unpack( "{$this->uint32}rev/{$this->uint32}total/{$this->uint32}originals_addr/{$this->uint32}translations_addr/{$this->uint32}hash_length/{$this->uint32}hash_addr", $offsets );

		if ( false === $offsets ) {
			return false;
		}

		$offsets['originals_length']    = $offsets['translations_addr'] - $offsets['originals_addr'];
		$offsets['translations_length'] = $offsets['hash_addr'] - $offsets['translations_addr'];

		if ( $offsets['rev'] > 0 ) {
			$this->error = 'Unsupported revision';
			return false;
		}

		if ( $offsets['translations_addr'] > $file_length || $offsets['originals_addr'] > $file_length ) {
			$this->error = 'Invalid data';
			return false;
		}

		// Load the Originals.
		$original_data     = str_split( substr( $file_contents, $offsets['originals_addr'], $offsets['originals_length'] ), 8 );
		$translations_data = str_split( substr( $file_contents, $offsets['translations_addr'], $offsets['translations_length'] ), 8 );

		foreach ( array_keys( $original_data ) as $i ) {
			$o = unpack( "{$this->uint32}length/{$this->uint32}pos", $original_data[ $i ] );
			$t = unpack( "{$this->uint32}length/{$this->uint32}pos", $translations_data[ $i ] );

			if ( false === $o || false === $t ) {
				continue;
			}

			$original    = substr( $file_contents, $o['pos'], $o['length'] );
			$translation = substr( $file_contents, $t['pos'], $t['length'] );
			// GlotPress bug.
			$translation = rtrim( $translation, "\0" );

			// Metadata about the MO file is stored in the first translation entry.
			if ( '' === $original ) {
				foreach ( explode( "\n", $translation ) as $meta_line ) {
					if ( '' === $meta_line || ! str_contains( $meta_line, ':' ) ) {
						continue;
					}

					list( $name, $value ) = array_map( 'trim', explode( ':', $meta_line, 2 ) );

					$this->headers[ strtolower( $name ) ] = $value;
				}
			} else {
				/*
				 * In MO files, the key normally contains both singular and plural versions.
				 * However, this just adds the singular string for lookup,
				 * which caters for cases where both __( 'Product' ) and _n( 'Product', 'Products' )
				 * are used and the translation is expected to be the same for both.
				 */
				$parts = explode( "\0", (string) $original );

				$this->entries[ $parts[0] ] = $translation;
			}
		}

		return true;
	}

	/**
	 * Exports translation contents as a string.
	 *
	 * @since 6.5.0
	 *
	 * @return string Translation file contents.
	 */
	public function export(): string {
		// Prefix the headers as the first key.
		$headers_string = '';
		foreach ( $this->headers as $header => $value ) {
			$headers_string .= "{$header}: $value\n";
		}
		$entries     = array_merge( array( '' => $headers_string ), $this->entries );
		$entry_count = count( $entries );

		if ( false === $this->uint32 ) {
			$this->uint32 = 'V';
		}

		$bytes_for_entries = $entry_count * 4 * 2;
		// Pair of 32bit ints per entry.
		$originals_addr    = 28; /* header */
		$translations_addr = $originals_addr + $bytes_for_entries;
		$hash_addr         = $translations_addr + $bytes_for_entries;
		$entry_offsets     = $hash_addr;

		$file_header = pack(
			$this->uint32 . '*',
			// Force cast to an integer as it can be a float on x86 systems. See https://core.trac.wordpress.org/ticket/60678.
			(int) self::MAGIC_MARKER,
			0, /* rev */
			$entry_count,
			$originals_addr,
			$translations_addr,
			0, /* hash_length */
			$hash_addr
		);

		$o_entries = '';
		$t_entries = '';
		$o_addr    = '';
		$t_addr    = '';

		foreach ( array_keys( $entries ) as $original ) {
			$o_addr        .= pack( $this->uint32 . '*', strlen( $original ), $entry_offsets );
			$entry_offsets += strlen( $original ) + 1;
			$o_entries     .= $original . "\0";
		}

		foreach ( $entries as $translations ) {
			$t_addr        .= pack( $this->uint32 . '*', strlen( $translations ), $entry_offsets );
			$entry_offsets += strlen( $translations ) + 1;
			$t_entries     .= $translations . "\0";
		}

		return $file_header . $o_addr . $t_addr . $o_entries . $t_entries;
	}
}
<?php
/**
 * I18N: WP_Translations class.
 *
 * @package WordPress
 * @subpackage I18N
 * @since 6.5.0
 */

/**
 * Class WP_Translations.
 *
 * @since 6.5.0
 *
 * @property-read array<string, string> $headers
 * @property-read array<string, string[]> $entries
 */
class WP_Translations {
	/**
	 * Text domain.
	 *
	 * @since 6.5.0
	 * @var string
	 */
	protected $textdomain = 'default';

	/**
	 * Translation controller instance.
	 *
	 * @since 6.5.0
	 * @var WP_Translation_Controller
	 */
	protected $controller;

	/**
	 * Constructor.
	 *
	 * @since 6.5.0
	 *
	 * @param WP_Translation_Controller $controller I18N controller.
	 * @param string                    $textdomain Optional. Text domain. Default 'default'.
	 */
	public function __construct( WP_Translation_Controller $controller, string $textdomain = 'default' ) {
		$this->controller = $controller;
		$this->textdomain = $textdomain;
	}

	/**
	 * Magic getter for backward compatibility.
	 *
	 * @since 6.5.0
	 *
	 * @param string $name Property name.
	 * @return mixed
	 */
	public function __get( string $name ) {
		if ( 'entries' === $name ) {
			$entries = $this->controller->get_entries( $this->textdomain );

			$result = array();

			foreach ( $entries as $original => $translations ) {
				$result[] = $this->make_entry( $original, $translations );
			}

			return $result;
		}

		if ( 'headers' === $name ) {
			return $this->controller->get_headers( $this->textdomain );
		}

		return null;
	}

	/**
	 * Builds a Translation_Entry from original string and translation strings.
	 *
	 * @see MO::make_entry()
	 *
	 * @since 6.5.0
	 *
	 * @param string $original     Original string to translate from MO file. Might contain
	 *                             0x04 as context separator or 0x00 as singular/plural separator.
	 * @param string $translations Translation strings from MO file.
	 * @return Translation_Entry Entry instance.
	 */
	private function make_entry( $original, $translations ): Translation_Entry {
		$entry = new Translation_Entry();

		// Look for context, separated by \4.
		$parts = explode( "\4", $original );
		if ( isset( $parts[1] ) ) {
			$original       = $parts[1];
			$entry->context = $parts[0];
		}

		$entry->singular     = $original;
		$entry->translations = explode( "\0", $translations );
		$entry->is_plural    = count( $entry->translations ) > 1;

		return $entry;
	}

	/**
	 * Translates a plural string.
	 *
	 * @since 6.5.0
	 *
	 * @param string|null $singular Singular string.
	 * @param string|null $plural   Plural string.
	 * @param int|float   $count    Count. Should be an integer, but some plugins pass floats.
	 * @param string|null $context  Context.
	 * @return string|null Translation if it exists, or the unchanged singular string.
	 */
	public function translate_plural( $singular, $plural, $count = 1, $context = '' ) {
		if ( null === $singular || null === $plural ) {
			return $singular;
		}

		$translation = $this->controller->translate_plural( array( $singular, $plural ), (int) $count, (string) $context, $this->textdomain );
		if ( false !== $translation ) {
			return $translation;
		}

		// Fall back to the original with English grammar rules.
		return ( 1 === (int) $count ? $singular : $plural );
	}

	/**
	 * Translates a singular string.
	 *
	 * @since 6.5.0
	 *
	 * @param string|null $singular Singular string.
	 * @param string|null $context  Context.
	 * @return string|null Translation if it exists, or the unchanged singular string
	 */
	public function translate( $singular, $context = '' ) {
		if ( null === $singular ) {
			return null;
		}

		$translation = $this->controller->translate( $singular, (string) $context, $this->textdomain );
		if ( false !== $translation ) {
			return $translation;
		}

		// Fall back to the original.
		return $singular;
	}
}