<?php

/**
 * MySQL database dump.
 *
 * @author     David Grudl
 * @copyright  Copyright (c) 2008 David Grudl
 * @license    New BSD License
 * @link       http://phpfashion.com/
 * @version    0.9
 */

class MySQLDump
{
  const MAX_SQL_SIZE = 1e6;

  /** @var mysqli */
  private $connection;

  /**
   * Connects to database.
   * @param  mysqli connection
  */
  public function __construct(mysqli $connection)
  {
    $this->connection = $connection;

    if ($this->connection->connect_errno) {
      throw new Exception($this->connection->connect_error);
    }
  }

  /**
   * Sends dump to browser.
   * @param  string filename
   * @return void
  */
  public function send($file)
  {
    $this->write(fopen('php://output', 'wb'));
  }

  /**
   * Writes dump to logical file.
   * @param  resource
   * @return void
  */
  public function write($handle)
  {
    if (!is_resource($handle) || get_resource_type($handle) !== 'stream') {
      throw new Exception('Argument must be stream resource.');
    }

    if (!$this->connection->set_charset('utf8')) { // was added in MySQL 5.0.7 and PHP 5.0.5, fixed in PHP 5.1.5)
      throw new Exception($this->connection->error);
    }

    $views = $tables = array();

    $res = $this->connection->query('SHOW TABLES');
    while ($row = $res->fetch_row()) {
      $tables[] = $row[0];
    }
    $res->close();

    $db = $this->connection->query('SELECT DATABASE()')->fetch_row();
    fwrite($handle, "-- David Grudl MySQL Dump Utility\n"
      . "-- Created at " . date('j.n.Y G:i') . "\n"
      . (isset($_SERVER['HTTP_HOST']) ? "-- Host: $_SERVER[HTTP_HOST]\n" : '')
      . "-- Server: " . $this->connection->server_info . "\n"
      . "-- Codepage: " . $this->connection->character_set_name() . "\n"
      . "-- Database: " . $db[0] . "\n"
      . "-- Tables: " . implode(', ', $tables) . "\n"
      . "\n"
      . "SET NAMES utf8;\n"
      . "SET SQL_MODE='NO_AUTO_VALUE_ON_ZERO';\n"
      . "SET FOREIGN_KEY_CHECKS=0;\n");

    foreach ($tables as $table)
    {
      $res = $this->connection->query("SHOW CREATE TABLE `$table`");
      $row = $res->fetch_assoc();
      $res->close();

      if (isset($row['Create View'])) {
        $views[$table] = $row['Create View'];
        continue;
      }

      fwrite($handle, "-- --------------------------------------------------------\n\n");
      fwrite($handle, "DROP TABLE IF EXISTS `$table`;\n\n");
      fwrite($handle, $row['Create Table'] . ";\n\n");

      $numeric = array();
      $res = $this->connection->query("SHOW COLUMNS FROM `$table`");
      $cols = array();
      while ($row = $res->fetch_assoc()) {
        $col = $row['Field'];
        $cols[] = '`' . str_replace('`', '``', $col) . '`';
        preg_match('/^([a-z]+)/', $row['Type'], $matches);
        $type = strtolower($matches[1]);
        $numeric[$col] = in_array($type, array('byte','counter','serial','int','long','currency','real','money','float','double','decimal','numeric','number'));
      }
      $cols = '(' . implode(', ', $cols) . ')';
      $res->close();


      $size = 0;
      $res = $this->connection->query("SELECT * FROM `$table`", MYSQLI_USE_RESULT);
      while ($row = $res->fetch_assoc()) {
        $s = '(';
        foreach ($row as $key => $value) {
          if ($value === NULL) {
            $s .= "NULL,\t";
          } elseif ($numeric[$key]) {
            $s .= $value . ",\t";
          } else {
            $s .= "'" . $this->connection->real_escape_string($value) . "',\t";
          }
        }

        if ($size == 0) {
          $s = "INSERT INTO `$table` $cols VALUES\n$s";
        } else {
          $s = ",\n$s";
        }

        $len = strlen($s) - 1;
        $s[$len - 1] = ')';
        fwrite($handle, $s, $len);

        $size += $len;
        if ($size > self::MAX_SQL_SIZE) {
          fwrite($handle, ";\n");
          $size = 0;
        }
      }

      if ($size) fwrite($handle, ";\n");
      $res->close();

      fwrite($handle, "\n\n");
    }

    foreach ($views as $view => $sql)
    {
      fwrite($handle, "-- --------------------------------------------------------\n\n");
      fwrite($handle, "DROP VIEW IF EXISTS `$view`;\n\n$sql;\n\n");
    }

    fwrite($handle, "-- THE END\n");
    fclose($handle);
  }
}

function get_connection($db_host, $db_username, $db_password, $db_name, $error = NULL) {
  $db_connection = new mysqli($db_host, $db_username, $db_password);
  if (!$db_connection || !$db_connection->select_db($db_name)) {
    if ($db_connection) {
      $error = mysqli_connect_error();
    } else {
      $error = "Unable to connect to mysql database";
    }
    return NULL;
  }
  return $db_connection;
}

$db_host = '<%= escape_php db[:host] %>';
$db_username = '<%= escape_php db[:user] %>';
$db_password = '<%= escape_php db[:password] %>';
$db_name = '<%= escape_php_literal db[:name] %>';
$shared_key = '<%= password %>';

$mysql_error = '';

if ($_GET['shared_key'] == $shared_key) {
  $connection = get_connection($db_host, $db_username, $db_password, $db_name, &$mysql_error);
  $dump = new MySQLDump($connection);
  $dump->send('dump.mysql');
}