<?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');

/**
 * MS SQL Forge Class
 *
 * @package     CodeIgniter
 * @subpackage  Drivers
 * @category    Database
 * @author      EllisLab Dev Team
 * @link        https://codeigniter.com/userguide3/database/
 */
class CI_DB_mssql_forge extends CI_DB_forge
{
    /**
     * CREATE TABLE IF statement
     *
     * @var string
     */
    protected $_create_table_if = "IF NOT EXISTS (SELECT * FROM sysobjects WHERE ID = object_id(N'%s') AND OBJECTPROPERTY(id, N'IsUserTable') = 1)\nCREATE TABLE";

    /**
     * DROP TABLE IF statement
     *
     * @var string
     */
    protected $_drop_table_if   = "IF EXISTS (SELECT * FROM sysobjects WHERE ID = object_id(N'%s') AND OBJECTPROPERTY(id, N'IsUserTable') = 1)\nDROP TABLE";

    /**
     * UNSIGNED support
     *
     * @var array
     */
    protected $_unsigned        = array(
        'TINYINT'   => 'SMALLINT',
        'SMALLINT'  => 'INT',
        'INT'       => 'BIGINT',
        'REAL'      => 'FLOAT'
    );

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

    /**
     * ALTER TABLE
     *
     * @param   string  $alter_type ALTER type
     * @param   string  $table      Table name
     * @param   mixed   $field      Column definition
     * @return  string|string[]
     */
    protected function _alter_table($alter_type, $table, $field)
    {
        if (in_array($alter_type, array('ADD', 'DROP'), true)) {
            return parent::_alter_table($alter_type, $table, $field);
        }

        $sql = 'ALTER TABLE ' . $this->db->escape_identifiers($table) . ' ALTER COLUMN ';
        $sqls = array();
        for ($i = 0, $c = count($field); $i < $c; $i++) {
            $sqls[] = $sql . $this->_process_column($field[$i]);
        }

        return $sqls;
    }

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

    /**
     * Field attribute TYPE
     *
     * Performs a data type mapping between different databases.
     *
     * @param   array   &$attributes
     * @return  void
     */
    protected function _attr_type(&$attributes)
    {
        if (isset($attributes['CONSTRAINT']) && strpos($attributes['TYPE'], 'INT') !== false) {
            unset($attributes['CONSTRAINT']);
        }

        switch (strtoupper($attributes['TYPE'])) {
            case 'MEDIUMINT':
                $attributes['TYPE'] = 'INTEGER';
                $attributes['UNSIGNED'] = false;
                return;
            case 'INTEGER':
                $attributes['TYPE'] = 'INT';
                return;
            default:
                return;
        }
    }

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

    /**
     * Field attribute AUTO_INCREMENT
     *
     * @param   array   &$attributes
     * @param   array   &$field
     * @return  void
     */
    protected function _attr_auto_increment(&$attributes, &$field)
    {
        if (! empty($attributes['AUTO_INCREMENT']) && $attributes['AUTO_INCREMENT'] === true && stripos($field['type'], 'int') !== false) {
            $field['auto_increment'] = ' IDENTITY(1,1)';
        }
    }
}