<?php

/**

 * Class for working with MO files

 *

 * @version $Id: mo.php 293 2009-11-12 15:43:50Z nbachiyski $

 * @package pomo

 * @subpackage mo

 */

require_once dirname(__FILE__) . '/translations.php';

require_once dirname(__FILE__) . '/streams.php';

if ( !class_exists( 'MO' ) ):

class MO extends Gettext_Translations {

	var $_nplurals = 2;

	/**

	 * Fills up with the entries from MO file $filename

	 *

	 * @param string $filename MO file to load

	 */

	function import_from_file($filename) {

		$reader = new POMO_FileReader($filename);

		if (!$reader->is_resource())

			return false;

		return $this->import_from_reader($reader);

	}

	function export_to_file($filename) {

		$fh = fopen($filename, 'wb');

		if ( !$fh ) return false;

		$entries = array_filter($this->entries, create_function('$e', 'return !empty($e->translations);'));

		ksort($entries);

		$magic = 0x950412de;

		$revision = 0;

		$total = count($entries) + 1; // all the headers are one entry

		$originals_lenghts_addr = 28;

		$translations_lenghts_addr = $originals_lenghts_addr + 8 * $total;

		$size_of_hash = 0;

		$hash_addr = $translations_lenghts_addr + 8 * $total;

		$current_addr = $hash_addr;

		fwrite($fh, pack('V*', $magic, $revision, $total, $originals_lenghts_addr,

			$translations_lenghts_addr, $size_of_hash, $hash_addr));

		fseek($fh, $originals_lenghts_addr);

		// headers' msgid is an empty string

		fwrite($fh, pack('VV', 0, $current_addr));

		$current_addr++;

		$originals_table = chr(0);

		foreach($entries as $entry) {

			$originals_table .= $this->export_original($entry) . chr(0);

			$length = strlen($this->export_original($entry));

			fwrite($fh, pack('VV', $length, $current_addr));

			$current_addr += $length + 1; // account for the NULL byte after

		}

		$exported_headers = $this->export_headers();

		fwrite($fh, pack('VV', strlen($exported_headers), $current_addr));

		$current_addr += strlen($exported_headers) + 1;

		$translations_table = $exported_headers . chr(0);

		foreach($entries as $entry) {

			$translations_table .= $this->export_translations($entry) . chr(0);

			$length = strlen($this->export_translations($entry));

			fwrite($fh, pack('VV', $length, $current_addr));

			$current_addr += $length + 1;

		}

		fwrite($fh, $originals_table);

		fwrite($fh, $translations_table);

		fclose($fh);

	}

	function export_original($entry) {

		//TODO: warnings for control characters

		$exported = $entry->singular;

		if ($entry->is_plural) $exported .= chr(0).$entry->plural;

		if (!is_null($entry->context)) $exported = $entry->context . chr(4) . $exported;

		return $exported;

	}

	function export_translations($entry) {

		//TODO: warnings for control characters

		return implode(chr(0), $entry->translations);

	}

	function export_headers() {

		$exported = '';

		foreach($this->headers as $header => $value) {

			$exported.= "$header: $value\n";

		}

		return $exported;

	}

	function get_byteorder($magic) {

		// The magic is 0x950412de

		// bug in PHP 5.0.2, see https://savannah.nongnu.org/bugs/?func=detailitem&item_id=10565

		$magic_little = (int) - 1794895138;

		$magic_little_64 = (int) 2500072158;

		// 0xde120495

		$magic_big = ((int) - 569244523) & 0xFFFFFFFF;

		if ($magic_little == $magic || $magic_little_64 == $magic) {

			return 'little';

		} else if ($magic_big == $magic) {

			return 'big';

		} else {

			return false;

		}

	}

	function import_from_reader($reader) {

		$endian_string = MO::get_byteorder($reader->readint32());

		if (false === $endian_string) {

			return false;

		}

		$reader->setEndian($endian_string);

		$endian = ('big' == $endian_string)? 'N' : 'V';

		$header = $reader->read(24);

		if ($reader->strlen($header) != 24)

			return false;

		// parse header

		$header = unpack("{$endian}revision/{$endian}total/{$endian}originals_lenghts_addr/{$endian}translations_lenghts_addr/{$endian}hash_length/{$endian}hash_addr", $header);

		if (!is_array($header))

			return false;

		extract( $header );

		// support revision 0 of MO format specs, only

		if ($revision != 0)

			return false;

		// seek to data blocks

		$reader->seekto($originals_lenghts_addr);

		// read originals' indices

		$originals_lengths_length = $translations_lenghts_addr - $originals_lenghts_addr;

		if ( $originals_lengths_length != $total * 8 )

			return false;

		$originals = $reader->read($originals_lengths_length);

		if ( $reader->strlen( $originals ) != $originals_lengths_length )

			return false;

		// read translations' indices

		$translations_lenghts_length = $hash_addr - $translations_lenghts_addr;

		if ( $translations_lenghts_length != $total * 8 )

			return false;

		$translations = $reader->read($translations_lenghts_length);

		if ( $reader->strlen( $translations ) != $translations_lenghts_length )

			return false;

		// transform raw data into set of indices

		$originals    = $reader->str_split( $originals, 8 );

		$translations = $reader->str_split( $translations, 8 );

		// skip hash table

		$strings_addr = $hash_addr + $hash_length * 4;

		$reader->seekto($strings_addr);

		$strings = $reader->read_all();

		$reader->close();

		for ( $i = 0; $i < $total; $i++ ) {

			$o = unpack( "{$endian}length/{$endian}pos", $originals[$i] );

			$t = unpack( "{$endian}length/{$endian}pos", $translations[$i] );

			if ( !$o || !$t ) return false;

			// adjust offset due to reading strings to separate space before

			$o['pos'] -= $strings_addr;

			$t['pos'] -= $strings_addr;

			$original    = $reader->substr( $strings, $o['pos'], $o['length'] );

			$translation = $reader->substr( $strings, $t['pos'], $t['length'] );

			if ('' === $original) {

				$this->set_headers($this->make_headers($translation));

			} else {

				$entry = &$this->make_entry($original, $translation);

				$this->entries[$entry->key()] = &$entry;

			}

		}

		return true;

	}

	/**

	 * Build a Translation_Entry from original string and translation strings,

	 * found in a MO file

	 * 

	 * @static

	 * @param string $original original string to translate from MO file. Might contain

	 * 	0x04 as context separator or 0x00 as singular/plural separator

	 * @param string $translation translation string from MO file. Might contain

	 * 	0x00 as a plural translations separator

	 */

	function &make_entry($original, $translation) {

		$entry = & new Translation_Entry();

		// look for context

		$parts = explode(chr(4), $original);

		if (isset($parts[1])) {

			$original = $parts[1];

			$entry->context = $parts[0];

		}

		// look for plural original

		$parts = explode(chr(0), $original);

		$entry->singular = $parts[0];

		if (isset($parts[1])) {

			$entry->is_plural = true;

			$entry->plural = $parts[1];

		}

		// plural translations are also separated by \0

		$entry->translations = explode(chr(0), $translation);

		return $entry;

	}

	function select_plural_form($count) {

		return $this->gettext_select_plural_form($count);

	}

	function get_plural_forms_count() {

		return $this->_nplurals;

	}

}

endif;