<?php

/*
 * This file is part of the Symfony package.
 *
 * (c) Fabien Potencier <fabien@symfony.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace Symfony\Component\Translation\Dumper;

use Symfony\Component\Translation\MessageCatalogue;
use Symfony\Component\Translation\Loader\MoFileLoader;

/**
 * MoFileDumper generates a gettext formated string representation of a message catalogue.
 *
 * @author Stealth35
 */
class MoFileDumper extends FileDumper
{
    /**
     * {@inheritDoc}
     */
    public function format(MessageCatalogue $messages, $domain = 'messages')
    {
        $output = $sources = $targets = $source_offsets = $target_offsets = '';
        $offsets = array();
        $size = 0;

        foreach ($messages->all($domain) as $source => $target) {
            $offsets[] = array_map('strlen', array($sources, $source, $targets, $target));
            $sources .= "\0".$source;
            $targets .= "\0".$target;
            ++$size;
        }

        $header = array(
            'magicNumber'      => MoFileLoader::MO_LITTLE_ENDIAN_MAGIC,
            'formatRevision'   => 0,
            'count'            => $size,
            'offsetId'         => MoFileLoader::MO_HEADER_SIZE,
            'offsetTranslated' => MoFileLoader::MO_HEADER_SIZE + (8 * $size),
            'sizeHashes'       => 0,
            'offsetHashes'     => MoFileLoader::MO_HEADER_SIZE + (16 * $size),
        );

        $sources_size  = strlen($sources);
        $sources_start = $header['offsetHashes'] + 1;

        foreach ($offsets as $offset) {
            $source_offsets .= $this->writeLong($offset[1])
                            .  $this->writeLong($offset[0] + $sources_start);
            $target_offsets .= $this->writeLong($offset[3])
                            .  $this->writeLong($offset[2] + $sources_start + $sources_size);
        }

        $output = implode(array_map(array($this, 'writeLong'), $header))
                . $source_offsets
                . $target_offsets
                . $sources
                . $targets
                ;

        return $output;
    }

    /**
     * {@inheritDoc}
     */
    protected function getExtension()
    {
        return 'mo';
    }

    private function writeLong($str)
    {
        return pack('V*', $str);
    }
}