<?php
/**
 * Class for working with MO files
 *
 * @version $Id: mo.php 718 2012-10-31 00:32:02Z 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
	 */
	public function import_from_file( $filename ) {
		$reader = new POMO_FileReader( $filename );
		if ( !$reader->is_resource() )
			return false;
		return $this->import_from_reader( $reader );
	}

	public function export_to_file( $filename ) {
		$fh = fopen( $filename, 'wb' );
		if ( !$fh ) return false;
		$res = $this->export_to_file_handle( $fh );
		fclose( $fh );
		return $res;
	}

	public function export() {
		$tmp_fh = fopen("php://temp", 'r+');
		if ( !$tmp_fh ) return false;
		$this->export_to_file_handle( $tmp_fh );
		rewind( $tmp_fh );
		return stream_get_contents( $tmp_fh );
	}

	public function is_entry_good_for_export( $entry ) {
		if ( empty( $entry->translations ) ) {
			return false;
		}

		if ( !array_filter( $entry->translations ) ) {
			return false;
		}

		return true;
	}

	public function export_to_file_handle( $fh ) {
		$entries = array_filter( $this->entries, array( $this, 'is_entry_good_for_export' ) );
		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 );

		$reader = new POMO_Reader();

		foreach($entries as $entry) {
			$originals_table .= $this->export_original( $entry ) . chr(0);
			$length = $reader->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', $reader->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 = $reader->strlen( $this->export_translations( $entry ) );
			fwrite( $fh, pack( 'VV', $length, $current_addr ) );
			$current_addr += $length + 1;
		}

		fwrite( $fh, $originals_table );
		fwrite( $fh, $translations_table );
		return true;
	}

	public 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;
	}

	public function export_translations( $entry ) {
		//TODO: warnings for control characters
		return implode( chr( 0 ), $entry->translations );
	}

	public 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;
		}
	}

	public 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;

		// support revision 0 of MO format specs, only
		if ( $header['revision'] != 0 ) {
			return false;
		}

		// seek to data blocks
		$reader->seekto( $header['originals_lenghts_addr'] );

		// read originals' indices
		$originals_lengths_length = $header['translations_lenghts_addr'] - $header['originals_lenghts_addr'];
		if ( $originals_lengths_length != $header['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 = $header['hash_addr'] - $header['translations_lenghts_addr'];
		if ( $translations_lenghts_length != $header['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 = $header['hash_addr'] + $header['hash_length'] * 4;

		$reader->seekto( $strings_addr );

		$strings = $reader->read_all();
		$reader->close();

		for ( $i = 0; $i < $header['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
	 */
	public 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;
	}

	public function select_plural_form( $count ) {
		return $this->gettext_select_plural_form( $count );
	}

	public function get_plural_forms_count() {
		return $this->_nplurals;
	}
}
endif;
