<?php

/**
 * CodeIgniter
 *
 * An open source application development framework for PHP
 *
 * This content is released under the MIT License (MIT)
 *
 * Copyright (c) 2019 - 2022, CodeIgniter Foundation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 * @package CodeIgniter
 * @author  EllisLab Dev Team
 * @copyright   Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
 * @copyright   Copyright (c) 2014 - 2019, British Columbia Institute of Technology (https://bcit.ca/)
 * @copyright   Copyright (c) 2019 - 2022, CodeIgniter Foundation (https://codeigniter.com/)
 * @license https://opensource.org/licenses/MIT MIT License
 * @link    https://codeigniter.com
 * @since   Version 1.3.0
 * @filesource
 */

defined('BASEPATH') or exit('No direct script access allowed');

/**
 * MySQLi Utility Class
 *
 * @package     CodeIgniter
 * @subpackage  Drivers
 * @category    Database
 * @author      EllisLab Dev Team
 * @link        https://codeigniter.com/userguide3/database/
 */
class CI_DB_mysqli_utility extends CI_DB_utility
{
    /**
     * List databases statement
     *
     * @var string
     */
    protected $_list_databases  = 'SHOW DATABASES';

    /**
     * OPTIMIZE TABLE statement
     *
     * @var string
     */
    protected $_optimize_table  = 'OPTIMIZE TABLE %s';

    /**
     * REPAIR TABLE statement
     *
     * @var string
     */
    protected $_repair_table    = 'REPAIR TABLE %s';

    // --------------------------------------------------------------------

    /**
     * Export
     *
     * @param   array   $params Preferences
     * @return  mixed
     */
    protected function _backup($params = array())
    {
        if (count($params) === 0) {
            return false;
        }

        // Extract the prefs for simplicity
        extract($params);

        // Build the output
        $output = '';

        // Do we need to include a statement to disable foreign key checks?
        if ($foreign_key_checks === false) {
            $output .= 'SET foreign_key_checks = 0;' . $newline;
        }

        foreach ((array) $tables as $table) {
            // Is the table in the "ignore" list?
            if (in_array($table, (array) $ignore, true)) {
                continue;
            }

            // Get the table schema
            $query = $this->db->query('SHOW CREATE TABLE ' . $this->db->escape_identifiers($this->db->database . '.' . $table));

            // No result means the table name was invalid
            if ($query === false) {
                continue;
            }

            // Write out the table schema
            $output .= '#' . $newline . '# TABLE STRUCTURE FOR: ' . $table . $newline . '#' . $newline . $newline;

            if ($add_drop === true) {
                $output .= 'DROP TABLE IF EXISTS ' . $this->db->protect_identifiers($table) . ';' . $newline . $newline;
            }

            $i = 0;
            $result = $query->result_array();
            foreach ($result[0] as $val) {
                if ($i++ % 2) {
                    $output .= $val . ';' . $newline . $newline;
                }
            }

            // If inserts are not needed we're done...
            if ($add_insert === false) {
                continue;
            }

            // Grab all the data from the current table
            $query = $this->db->query('SELECT * FROM ' . $this->db->protect_identifiers($table));

            if ($query->num_rows() === 0) {
                continue;
            }

            // Fetch the field names and determine if the field is an
            // integer type. We use this info to decide whether to
            // surround the data with quotes or not

            $i = 0;
            $field_str = '';
            $is_int = array();
            while ($field = $query->result_id->fetch_field()) {
                // Most versions of MySQL store timestamp as a string
                $is_int[$i] = in_array($field->type, array(MYSQLI_TYPE_TINY, MYSQLI_TYPE_SHORT, MYSQLI_TYPE_INT24, MYSQLI_TYPE_LONG), true);

                // Create a string of field names
                $field_str .= $this->db->escape_identifiers($field->name) . ', ';
                $i++;
            }

            // Trim off the end comma
            $field_str = preg_replace('/, $/', '', $field_str);

            // Build the insert string
            foreach ($query->result_array() as $row) {
                $val_str = '';

                $i = 0;
                foreach ($row as $v) {
                    // Is the value NULL?
                    if ($v === null) {
                        $val_str .= 'NULL';
                    } else {
                        // Escape the data if it's not an integer
                        $val_str .= ($is_int[$i] === false) ? $this->db->escape($v) : $v;
                    }

                    // Append a comma
                    $val_str .= ', ';
                    $i++;
                }

                // Remove the comma at the end of the string
                $val_str = preg_replace('/, $/', '', $val_str);

                // Build the INSERT string
                $output .= 'INSERT INTO ' . $this->db->protect_identifiers($table) . ' (' . $field_str . ') VALUES (' . $val_str . ');' . $newline;
            }

            $output .= $newline . $newline;
        }

        // Do we need to include a statement to re-enable foreign key checks?
        if ($foreign_key_checks === false) {
            $output .= 'SET foreign_key_checks = 1;' . $newline;
        }

        return $output;
    }
}