<?php
/**
 * ARC2 Store Dumper
 *
 * @author Benjamin Nowack
 * @license W3C Software License and GPL
 * @homepage <https://github.com/semsol/arc2>
 * @package ARC2
 * @version 2010-11-16
*/

ARC2::inc('Class');

class ARC2_StoreDumper extends ARC2_Class {

  function __construct($a, &$caller) {
    parent::__construct($a, $caller);
  }
  
  function __init() {
    parent::__init();
    $this->store = $this->caller;
    $this->keep_time_limit = $this->v('keep_time_limit', 0, $this->a);
    $this->limit = 100000;
  }

  /*  */
  
  function dumpSPOG() {
    header('Content-Type: application/sparql-results+xml');
    if ($this->v('store_use_dump_dir', 0, $this->a)) {
      $path = $this->v('store_dump_dir', 'dumps', $this->a);
      /* default: monthly dumps */
      $path_suffix = $this->v('store_dump_suffix', date('Y_m'), $this->a);
      $path .= '/dump_' . $path_suffix . '.spog';
      if (!file_exists($path)) {
        $this->saveSPOG($path);
      }
      readfile($path);
      exit;
    }
    echo $this->getHeader();
    $offset = 0;
    do {
      $proceed = 0;
      $rs = $this->getRecordset($offset);
      if (!$rs) break;
      while ($row = mysqli_fetch_array($rs)) {
        echo $this->getEntry($row);
        $proceed = 1;
      }
      $offset += $this->limit;
    } while ($proceed);
    echo $this->getFooter();
  }

  /*  */

  function saveSPOG($path, $q = '') {
    if ($q) return $this->saveCustomSPOG($path, $q);
    if (!$fp = @fopen($path, 'w')) return $this->addError('Could not create backup file at ' . realpath($path));
    fwrite($fp, $this->getHeader());
    $offset = 0;
    do {
      $proceed = 0;
      $rs = $this->getRecordset($offset);
      if (!$rs) break;
      while ($row = mysqli_fetch_array($rs)) {
        fwrite($fp, $this->getEntry($row));
        $proceed = 1;
      }
      $offset += $this->limit;
    } while ($proceed);
    fwrite($fp, $this->getFooter());
    @fclose($fp);
    return 1;
  }

  /*  */

  function saveCustomSPOG($path, $q) {
    if (!$fp = @fopen($path, 'w')) return $this->addError('Could not create backup file at ' . realpath($path));
    fwrite($fp, $this->getHeader());
    $rows = $this->store->query($q, 'rows');
    foreach ($rows as $row) {
      fwrite($fp, $this->getEntry($row));
    }
    fwrite($fp, $this->getFooter());
    @fclose($fp);
  }
  
  /*  */

  function getRecordset($offset) {
    $prefix = $this->store->getTablePrefix();
    $con = $this->store->getDBCon();
    $sql = '
      SELECT 
        VS.val AS s,
        T.s_type AS `s type`,
        VP.val AS p,
        0 AS `p type`,
        VO.val AS o,
        T.o_type AS `o type`,
        VLDT.val as `o lang_dt`,
        VG.val as g,
        0 AS `g type`
      FROM
        ' . $prefix . 'triple T
        JOIN ' . $prefix . 's2val VS ON (T.s = VS.id)
        JOIN ' . $prefix . 'id2val VP ON (T.p = VP.id)
        JOIN ' . $prefix . 'o2val VO ON (T.o = VO.id)
        JOIN ' . $prefix . 'id2val VLDT ON (T.o_lang_dt = VLDT.id)
        JOIN ' . $prefix . 'g2t G2T ON (T.t = G2T.t)
        JOIN ' . $prefix . 'id2val VG ON (G2T.g = VG.id)
    ';
    if ($this->limit) $sql .= ' LIMIT ' . $this->limit;
    if ($offset) $sql .= ' OFFSET ' . $offset;
    $rs = mysqli_query( $con, $sql, MYSQLI_USE_RESULT);
    $err = mysqli_error($con);
    if (!empty($err)) {
      return $this->addError($err);
    }
    return $rs;
  }

  /*  */
  
  function getHeader() {
    $n = "\n";
    return '' .
      '<?xml version="1.0"?>' . 
      $n . '<sparql xmlns="http://www.w3.org/2005/sparql-results#">' .
      $n . '  <head>' .
      $n . '    <variable name="s"/>' .
      $n . '    <variable name="p"/>' .
      $n . '    <variable name="o"/>' .
      $n . '    <variable name="g"/>' .
      $n . '  </head>' .
      $n . '  <results>' .
    '';
  }

  function getEntry($row) {
    if (!$this->keep_time_limit) @set_time_limit($this->v('time_limit', 1200, $this->a));
    $n = "\n";
    $r = '';
    $r .= $n . '    <result>';
    foreach (array('s', 'p', 'o', 'g') as $var) {
      if (isset($row[$var])) {
        $type = (string) $row[$var . ' type'];
        $r .= $n . '      <binding name="' . $var . '">';
        $val = $this->toUTF8($row[$var]);
        if (($type == '0') || ($type == 'uri')) {
          $r .= $n . '        <uri>' . $this->getSafeValue($val) . '</uri>';
        }
        elseif (($type == '1') || ($type == 'bnode')) {
          $r .= $n . '        <bnode>' . substr($val, 2) . '</bnode>';
        }
        else {
          $lang_dt = '';
          foreach (array('o lang_dt', 'o lang', 'o datatype') as $k) {
            if (($var == 'o') && isset($row[$k]) && $row[$k]) $lang_dt = $row[$k];
          }
          $is_lang = preg_match('/^([a-z]+(\-[a-z0-9]+)*)$/i', $lang_dt);
          list($lang, $dt) = $is_lang ? array($lang_dt, '') : array('', $lang_dt);
          $lang = $lang ? ' xml:lang="' . $lang . '"' : '';
          $dt = $dt ? ' datatype="' . htmlspecialchars($dt) . '"' : '';
          $r .= $n . '        <literal' . $dt . $lang . '>' . $this->getSafeValue($val) . '</literal>';
        }
        $r .= $n . '      </binding>';
      }
    }
    $r .= $n . '    </result>';
    return $r;
  }

  function getSafeValue($val) {/* mainly for fixing json_decode bugs */
    $mappings = array(
      '%00' => '',
      '%01' => '',
      '%02' => '',
      '%03' => '',
      '%04' => '',
      '%05' => '',
      '%06' => '',
      '%07' => '',
      '%08' => '',
      '%09' => '',
      '%0B' => '',
      '%0C' => '',
      '%0E' => '',
      '%0F' => '',
      '%15' => '',
      '%17' => 'ė',
      '%1A' => ',',
      '%1F' => '',
    );
    $froms = array_keys($mappings);
    $tos = array_values($mappings);
    foreach ($froms as $i => $from) $froms[$i] = urldecode($from);
    $val = str_replace($froms, $tos, $val);
    if (strpos($val, '</') !== false) {
      $val = "\n<![CDATA[\n" . $val . "\n]]>\n";
    }
    else {
      $val = htmlspecialchars($val);
    }
    return $val;
  }

  function getFooter() {
    $n = "\n";
    return '' .
      $n . '  </results>' .
      $n . '</sparql>' . 
      $n .
    '';
  }

  /*  */

}