<?php
/**
 * FuzeWorks Framework Database Component.
 *
 * The FuzeWorks PHP FrameWork
 *
 * Copyright (C) 2013-2018 TechFuze
 *
 * 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.
 *
 * @author    TechFuze
 * @copyright Copyright (c) 2013 - 2018, TechFuze. (http://techfuze.net)
 * @license   https://opensource.org/licenses/MIT MIT License
 *
 * @link  http://techfuze.net/fuzeworks
 * @since Version 1.1.4
 *
 * @version Version 1.1.4
 */

/**
 * PDO Oracle Forge Class
 *
 * Converted from CodeIgniter.
 *
 * @package		FuzeWorks
 * @category	Database
 * @author		EllisLab Dev Team
 * @link		https://codeigniter.com/user_guide/database/
 * @license		http://opensource.org/licenses/MIT	MIT License
 */
class FW_DB_pdo_oci_forge extends FW_DB_pdo_forge {

	/**
	 * CREATE DATABASE statement
	 *
	 * @var	string
	 */
	protected $_create_database	= FALSE;

	/**
	 * DROP DATABASE statement
	 *
	 * @var	string
	 */
	protected $_drop_database	= FALSE;

	/**
	 * CREATE TABLE IF statement
	 *
	 * @var	string
	 */
	protected $_create_table_if	= 'CREATE TABLE IF NOT EXISTS';

	/**
	 * UNSIGNED support
	 *
	 * @var	bool|array
	 */
	protected $_unsigned		= FALSE;

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

	/**
	 * 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, $field)
	{
		if ($alter_type === 'DROP')
		{
			return parent::_alter_table($alter_type, $table, $field);
		}
		elseif ($alter_type === 'CHANGE')
		{
			$alter_type = 'MODIFY';
		}

		$sql = 'ALTER TABLE '.$this->db->escape_identifiers($table);
		$sqls = array();
		for ($i = 0, $c = count($field); $i < $c; $i++)
		{
			if ($field[$i]['_literal'] !== FALSE)
			{
				$field[$i] = "\n\t".$field[$i]['_literal'];
			}
			else
			{
				$field[$i]['_literal'] = "\n\t".$this->_process_column($field[$i]);

				if ( ! empty($field[$i]['comment']))
				{
					$sqls[] = 'COMMENT ON COLUMN '
						.$this->db->escape_identifiers($table).'.'.$this->db->escape_identifiers($field[$i]['name'])
						.' IS '.$field[$i]['comment'];
				}

				if ($alter_type === 'MODIFY' && ! empty($field[$i]['new_name']))
				{
					$sqls[] = $sql.' RENAME COLUMN '.$this->db->escape_identifiers($field[$i]['name'])
						.' '.$this->db->escape_identifiers($field[$i]['new_name']);
				}
			}
		}

		$sql .= ' '.$alter_type.' ';
		$sql .= (count($field) === 1)
				? $field[0]
				: '('.implode(',', $field).')';

		// RENAME COLUMN must be executed after MODIFY
		array_unshift($sqls, $sql);
		return $sql;
	}

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

	/**
	 * Field attribute AUTO_INCREMENT
	 *
	 * @param	array	&$attributes
	 * @param	array	&$field
	 * @return	void
	 */
	protected function _attr_auto_increment(&$attributes, &$field)
	{
		// Not supported - sequences and triggers must be used instead
	}

}