<?php

/**
 * @file
 */

require_once dirname(__FILE__) . '/sources.db.inc';

/**
 * @file
 * Functions to handle the direct to database source.
 */

/**
 * A source type for backing up from database server.
 *
 * @ingroup backup_migrate_destinations
 */
class backup_migrate_source_db_mysql extends backup_migrate_source_db {

  /**
   * The table's data keyed by table name.
   *
   * @var array
   */
  protected static $tableData = array();

  /**
   * The tables keyed by name.
   *
   * @var array
   */
  protected static $tableNames = array();

  /**
   * The views keyed by name.
   *
   * @var array
   */
  protected static $viewNames = array();

  /**
   *
   */
  public function type_name() {
    return t("MySQL Database");
  }

  /**
   * Return a list of backup filetypes.
   */
  public function file_types() {
    return array(
      "sql" => array(
        "extension" => "sql",
        "filemime" => "text/x-sql",
        "backup" => TRUE,
        "restore" => TRUE,
      ),
      "mysql" => array(
        "extension" => "mysql",
        "filemime" => "text/x-sql",
        "backup" => TRUE,
        "restore" => TRUE,
      ),
    );
  }

  /**
   * Return the scheme for this db type.
   */
  public function default_scheme() {
    return 'mysql';
  }

  /**
   * Declare any mysql databases defined in the settings.php file as a possible source.
   */
  public function sources() {
    $out = array();
    global $databases;
    foreach ((array) $databases as $db_key => $target) {
      foreach ((array) $target as $tgt_key => $info) {
        // Only mysql/mysqli supported by this source.
        $key = $db_key . ':' . $tgt_key;
        if ($info['driver'] === 'mysql') {
          // Compile the database connection string.
          $url = 'mysql://';
          $url .= urlencode($info['username']) . ':' . urlencode($info['password']);
          $url .= '@';
          $url .= urlencode($info['host']);
          if (!empty($info['port'])) {
            $url .= ':' . $info['port'];
          }
          $url .= '/' . urlencode($info['database']);

          if ($source = backup_migrate_create_destination('mysql', array('url' => $url))) {
            // Treat the default database differently because it is probably
            // the only one available.
            if ($key == 'default:default') {
              $source->set_id('db');
              $source->set_name(t('Default Database'));
              // Dissalow backing up to the default database because that's confusing and potentially dangerous.
              $source->remove_op('scheduled backup');
              $source->remove_op('manual backup');
            }
            else {
              $source->set_id('db:' . $key);
              $source->set_name($key . ": " . $source->get_display_location());
            }
            $out[$source->get_id()] = $source;
          }
        }
      }
    }
    return $out;
  }

  /**
   * Get the file type for to backup this source to.
   */
  public function get_file_type_id() {
    return 'mysql';
  }

  /**
   * Backup the databases to a file.
   *
   *  Returns a list of sql commands, one command per line.
   *  That makes it easier to import without loading the whole file into memory.
   *  The files are a little harder to read, but human-readability is not a priority.
   */
  public function _backup_db_to_file($file, $settings) {
    if (!empty($settings->filters['use_cli']) && $this->_backup_db_to_file_mysqldump($file, $settings)) {
      return TRUE;
    }

    $lines = 0;
    $exclude = !empty($settings->filters['exclude_tables']) ? $settings->filters['exclude_tables'] : array();
    $nodata = !empty($settings->filters['nodata_tables']) ? $settings->filters['nodata_tables'] : array();
    if ($file->open(TRUE)) {
      $file->write($this->_get_sql_file_header());
      $alltables = $this->_get_tables();
      $allviews = $this->_get_views();

      foreach ($alltables as $table) {
        if (_backup_migrate_check_timeout()) {
          return FALSE;
        }
        if ($table['name'] && !isset($exclude[$table['name']])) {
          $file->write($this->_get_table_structure_sql($table));
          $lines++;
          if (!in_array($table['name'], $nodata)) {
            $lines += $this->_dump_table_data_sql_to_file($file, $table);
          }
        }
      }
      foreach ($allviews as $view) {
        if (_backup_migrate_check_timeout()) {
          return FALSE;
        }
        if ($view['name'] && !isset($exclude[$view['name']])) {
          $file->write($this->_get_view_create_sql($view));
        }
      }
      $file->write($this->_get_sql_file_footer());
      $file->close();
      return $lines;
    }
    else {
      return FALSE;
    }
  }

  /**
   * Backup the databases to a file using the mysqldump command.
   */
  public function _backup_db_to_file_mysqldump($file, $settings) {
    $success = FALSE;
    $nodata_tables = array();
    $alltables = $this->_get_tables();

    $command = 'mysqldump --result-file=%file --opt -Q --host=%host --port=%port --user=%user --password=%pass %db';
    $args = array(
      '%file' => $file->filepath(),
      '%host' => $this->dest_url['host'],
      '%port' => isset($this->dest_url['port']) ? $this->dest_url['port'] : '3306',
      '%user' => $this->dest_url['user'],
      '%pass' => $this->dest_url['pass'],
      '%db' => $this->dest_url['path'],
    );

    // Ignore the excluded and no-data tables.
    $db = $this->dest_url['path'];
    if (!empty($settings->filters['exclude_tables'])) {
      foreach ((array) $settings->filters['exclude_tables'] as $table) {
        if (isset($alltables[$table])) {
          $command .= ' --ignore-table=' . $db . '.' . $table;
        }
      }
    }
    if (!empty($settings->filters['nodata_tables'])) {
      foreach ((array) $settings->filters['nodata_tables'] as $table) {
        if (isset($alltables[$table])) {
          $nodata_tables[] = $table;
          $command .= ' --ignore-table=' . $db . '.' . $table;
        }
      }
    }
    $success = backup_migrate_exec($command, $args);

    // Get the nodata tables.
    if ($success && !empty($nodata_tables)) {
      $tables = implode(' ', array_unique($nodata_tables));
      $command = "mysqldump --no-data --opt -Q --host=%host --port=%port --user=%user --password=%pass %db $tables >> %file";
      $success = backup_migrate_exec($command, $args);
    }
    return $success;
  }

  /**
   * Backup the databases to a file.
   */
  public function _restore_db_from_file($file, $settings) {
    $num = 0;

    if ($file->open() && $conn = $this->_get_db_connection()) {
      // Optionally drop all existing tables.
      if (!empty($settings->filters['utils_drop_all_tables'])) {
        $all_tables = $this->_get_tables();
        $table_names = array_map('backup_migrate_array_name_value', $all_tables);
        $table_list = join(', ', $table_names);
        $stmt = $conn->prepare("DROP TABLE IF EXISTS $table_list;\n");
        $stmt->execute();
      }

      // Read one line at a time and run the query.
      while ($line = $this->_read_sql_command_from_file($file)) {
        if (_backup_migrate_check_timeout()) {
          return FALSE;
        }
        if ($line) {
          // Prepeare and exexute the statement instead of the api function to avoid substitution of '{' etc.
          $stmt = $conn->prepare($line);
          $stmt->execute();
          $num++;
        }
      }
      // Close the file with fclose/gzclose.
      $file->close();
    }
    else {
      drupal_set_message(t("Unable to open file %file to restore database", array("%file" => $file->filepath())), 'error');
      $num = FALSE;
    }
    return $num;
  }

  /**
   * Read a multiline sql command from a file.
   *
   * Supports the formatting created by mysqldump, but won't handle multiline comments.
   */
  public function _read_sql_command_from_file($file) {
    $out = '';
    while ($line = $file->read()) {
      $first2 = substr($line, 0, 2);
      $first3 = substr($line, 0, 3);

      // Ignore single line comments. This function doesn't support multiline comments or inline comments.
      if ($first2 != '--' && ($first2 != '/*' || $first3 == '/*!')) {
        $out .= ' ' . trim($line);
        // If a line ends in ; or */ it is a sql command.
        if (substr($out, strlen($out) - 1, 1) == ';') {
          return trim($out);
        }
      }
    }
    return trim($out);
  }

  /**
   * Get a list of tables in the database.
   */
  public function _get_table_names() {
    if (empty(static::$tableNames)) {
      static::$tableNames = $this->query("SHOW FULL TABLES WHERE Table_Type = 'BASE TABLE'")
        ->fetchAllKeyed(0, 0);
    }

    return static::$tableNames;
  }

  /**
   * Get a list of views in the database.
   */
  public function _get_view_names() {
    if (empty(static::$viewNames)) {
      static::$viewNames = $this->query("SHOW FULL TABLES WHERE Table_Type = 'VIEW'")
        ->fetchAllKeyed(0, 0);
    }

    return static::$viewNames;
  }

  /**
   * Lock the list of given tables in the database.
   */
  public function _lock_tables($tables) {
    if ($tables) {
      $tables_escaped = array();
      foreach ($tables as $table) {
        $tables_escaped[] = '`' . db_escape_table($table) . '`  WRITE';
      }
      $this->query('LOCK TABLES ' . implode(', ', $tables_escaped));
    }
  }

  /**
   * Unlock all tables in the database.
   */
  public function _unlock_tables($settings) {
    $this->query('UNLOCK TABLES');
  }

  /**
   * Get a list of table and view data in the db.
   */
  protected function get_table_data() {
    if (empty(static::$tableData)) {
      $tables = $this->query('SHOW TABLE STATUS')->fetchAll(PDO::FETCH_ASSOC);

      foreach ($tables as $table) {
        // Lowercase the keys because between Drupal 7.12 and 7.13/14 the
        // default query behavior was changed.
        // See: http://drupal.org/node/1171866
        $table = array_change_key_case($table);
        static::$tableData[$table['name']] = $table;
      }
    }

    return static::$tableData;
  }

  /**
   * Get a list of tables in the db.
   */
  public function _get_tables() {
    $out = array();
    foreach ($this->get_table_data() as $table) {
      if (!empty($table['engine'])) {
        $out[$table['name']] = $table;
      }
    }

    return $out;
  }

  /**
   * Get a list of views in the db.
   */
  public function _get_views() {
    $out = array();
    foreach ($this->get_table_data() as $table) {
      if (empty($table['engine'])) {
        $out[$table['name']] = $table;
      }
    }
    return $out;
  }

  /**
   * Get the sql for the structure of the given view.
   */
  public function _get_view_create_sql($view) {
    $out = "";
    // Switch SQL mode to get rid of "CREATE ALGORITHM..." what requires more permissions + troubles with the DEFINER user.
    $sql_mode = $this->query("SELECT @@SESSION.sql_mode")->fetchField();
    $this->query("SET sql_mode = 'ANSI'");
    $result = $this->query("SHOW CREATE VIEW `" . $view['name'] . "`", array(), array('fetch' => PDO::FETCH_ASSOC));
    $this->query("SET SQL_mode = :mode", array(':mode' => $sql_mode));
    foreach ($result as $create) {
      // Lowercase the keys because between Drupal 7.12 and 7.13/14 the default query behavior was changed.
      // See: http://drupal.org/node/1171866
      $create = array_change_key_case($create);
      $out .= "DROP VIEW IF EXISTS `" . $view['name'] . "`;\n";
      $out .= "SET sql_mode = 'ANSI';\n";
      $out .= strtr($create['create view'], "\n", " ") . ";\n";
      $out .= "SET sql_mode = '$sql_mode';\n";
    }
    return $out;
  }

  /**
   * Get the sql for the structure of the given table.
   */
  public function _get_table_structure_sql($table) {
    $out = "";
    $result = $this->query("SHOW CREATE TABLE `" . $table['name'] . "`", array(), array('fetch' => PDO::FETCH_ASSOC));
    foreach ($result as $create) {
      // Lowercase the keys because between Drupal 7.12 and 7.13/14 the default query behavior was changed.
      // See: http://drupal.org/node/1171866
      $create = array_change_key_case($create);
      $out .= "DROP TABLE IF EXISTS `" . $table['name'] . "`;\n";
      // Remove newlines and convert " to ` because PDO seems to convert those for some reason.
      $out .= strtr($create['create table'], array("\n" => ' ', '"' => '`'));
      if ($table['auto_increment']) {
        $out .= " AUTO_INCREMENT=" . $table['auto_increment'];
      }
      $out .= ";\n";
    }
    return $out;
  }

  /**
   * Get the sql to insert the data for a given table.
   */
  public function _dump_table_data_sql_to_file($file, $table) {
    $rows_per_query = variable_get('backup_migrate_data_rows_per_query', BACKUP_MIGRATE_DATA_ROWS_PER_QUERY);
    $rows_per_line = variable_get('backup_migrate_data_rows_per_line', BACKUP_MIGRATE_DATA_ROWS_PER_LINE);
    $bytes_per_line = variable_get('backup_migrate_data_bytes_per_line', BACKUP_MIGRATE_DATA_BYTES_PER_LINE);

    if (variable_get('backup_migrate_verbose')) {
      _backup_migrate_message('Table: %table', array('%table' => $table['name']), 'success');
    }

    // Escape backslashes, PHP code, special chars.
    $search = array('\\', "'", "\x00", "\x0a", "\x0d", "\x1a");
    $replace = array('\\\\', "''", '\0', '\n', '\r', '\Z');

    $lines = 0;
    $from = 0;
    $args = array('fetch' => PDO::FETCH_ASSOC);
    while ($data = $this->query("SELECT * FROM `" . $table['name'] . "`", array(), $args, $from, $rows_per_query)) {
      if ($data->rowCount() == 0) {
        break;
      }

      $rows = $bytes = 0;

      $line = array();
      foreach ($data as $row) {
        $from++;

        // DB Escape the values.
        $items = array();
        foreach ($row as $key => $value) {
          $items[] = is_null($value) ? "null" : "'" . str_replace($search, $replace, $value) . "'";
        }

        // If there is a row to be added.
        if ($items) {
          // Start a new line if we need to.
          if ($rows == 0) {
            $file->write("INSERT INTO `" . $table['name'] . "` VALUES ");
            $bytes = $rows = 0;
          }
          // Otherwise add a comma to end the previous entry.
          else {
            $file->write(",");
          }

          // Write the data itself.
          $sql = implode(',', $items);
          $file->write('(' . $sql . ')');
          $bytes += strlen($sql);
          $rows++;

          // Finish the last line if we've added enough items.
          if ($rows >= $rows_per_line || $bytes >= $bytes_per_line) {
            $file->write(";\n");
            $lines++;
            $bytes = $rows = 0;
          }
        }
      }

      // Finish any unfinished insert statements.
      if ($rows > 0) {
        $file->write(";\n");
        $lines++;
      }
    }

    if (variable_get('backup_migrate_verbose')) {
      _backup_migrate_message('Peak memory usage: %mem', array('%mem' => backup_migrate_get_peak_memory_usage() . 'MB'), 'success');
    }

    return $lines;
  }

  /**
   * Get the db connection for the specified db.
   */
  public function _get_db_connection() {
    if (!$this->connection) {
      $this->connection = parent::_get_db_connection();
      // Set the sql mode because the default is ANSI,TRADITIONAL which is not aware of collation or storage engine.
      $this->connection->exec("SET sql_mode=''");
    }
    return $this->connection;
  }

  /**
   * Run a query on this source's database using Drupal's MySQL engine.
   *
   * @param string $query
   *   The query string.
   * @param array $args
   *   Arguments for the query.
   * @param array $options
   *   Options to pass to the query.
   * @param int|null $from
   *   The starting point for the query; when passed will perform a queryRange()
   *   method instead of a regular query().
   * @param int|null $count
   *   The number of records to obtain from this query. Will be ignored if the
   *   $from argument is empty.
   *
   * @see DatabaseConnection_mysql::query()
   * @see DatabaseConnection_mysql::queryRange()
   */
  public function query($query, array $args = array(), array $options = array(), $from = NULL, $count = NULL) {
    if ($conn = $this->_get_db_connection()) {
      // If no $from is passed in, just do a basic query.
      if (is_null($from)) {
        return $conn->query($query, $args, $options);
      }
      // The $from variable was passed in, so do a ranged query.
      else {
        return $conn->queryRange($query, $from, $count, $args, $options);
      }
    }
  }

  /**
   * The header for the top of the sql dump file. These commands set the connection
   *  character encoding to help prevent encoding conversion issues.
   */
  public function _get_sql_file_header() {
    $info = $this->_db_info();

    return "-- Backup and Migrate (Drupal) MySQL Dump
-- Backup and Migrate Version: " . BACKUP_MIGRATE_VERSION . "
-- http://drupal.org/project/backup_migrate
-- Drupal Version: " . VERSION . "
-- http://drupal.org/
--
-- Host: " . url('', array('absolute' => TRUE)) . "
-- Site Name: " . url('', array('absolute' => TRUE)) . "
-- Generation Time: " . format_date(time(), 'custom', 'r') . "
-- MySQL Version: " . $info['version'] . "

/*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */;
/*!40101 SET @OLD_CHARACTER_SET_RESULTS=@@CHARACTER_SET_RESULTS */;
/*!40101 SET @OLD_COLLATION_CONNECTION=@@COLLATION_CONNECTION */;
/*!40014 SET @OLD_UNIQUE_CHECKS=@@UNIQUE_CHECKS, UNIQUE_CHECKS=0 */;
/*!40014 SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0 */;
/*!40101 SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE=NO_AUTO_VALUE_ON_ZERO */;

SET SQL_MODE=\"NO_AUTO_VALUE_ON_ZERO\";
SET NAMES utf8mb4;

";
  }

  /**
   * The footer of the sql dump file.
   */
  public function _get_sql_file_footer() {
    return "

/*!40101 SET SQL_MODE=@OLD_SQL_MODE */;
/*!40014 SET FOREIGN_KEY_CHECKS=@OLD_FOREIGN_KEY_CHECKS */;
/*!40014 SET UNIQUE_CHECKS=@OLD_UNIQUE_CHECKS */;
/*!40101 SET CHARACTER_SET_RESULTS=@OLD_CHARACTER_SET_RESULTS */;
/*!40101 SET COLLATION_CONNECTION=@OLD_COLLATION_CONNECTION */;
/*!40101 SET CHARACTER_SET_CLIENT=@OLD_CHARACTER_SET_CLIENT */;
";
  }

  /**
   * Get the version info for the given DB.
   */
  public function _db_info() {
    $db = $this->_get_db_connection();
    return array(
      'type' => 'mysql',
      'version' => $db ? $db->version() : t('Unknown'),
    );
  }

}
