<?php
/**
 * CodeIgniter
 *
 * An open source application development framework for PHP
 *
 * This content is released under the MIT License (MIT)
 *
 * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
 *
 * 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. (http://ellislab.com/)
 * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
 * @license	http://opensource.org/licenses/MIT	MIT License
 * @link	http://codeigniter.com
 * @since	Version 3.0.0
 * @filesource
 */
defined('BASEPATH') OR exit('No direct script access allowed');

/**
 * Interbase/Firebird Forge Class
 *
 * @category	Database
 * @author		EllisLab Dev Team
 * @link		http://codeigniter.com/user_guide/database/
 */
class CI_DB_ibase_forge extends CI_DB_forge {

	/**
	 * CREATE TABLE IF statement
	 *
	 * @var	string
	 */
	protected $_create_table_if	= FALSE;

	/**
	 * RENAME TABLE statement
	 *
	 * @var	string
	 */
	protected $_rename_table	= FALSE;

	/**
	 * DROP TABLE IF statement
	 *
	 * @var	string
	 */
	protected $_drop_table_if	= FALSE;

	/**
	 * UNSIGNED support
	 *
	 * @var	array
	 */
	protected $_unsigned		= array(
		'SMALLINT'	=> 'INTEGER',
		'INTEGER'	=> 'INT64',
		'FLOAT'		=> 'DOUBLE PRECISION'
	);

	/**
	 * NULL value representation in CREATE/ALTER TABLE statements
	 *
	 * @var	string
	 */
	protected $_null		= 'NULL';

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

	/**
	 * Create database
	 *
	 * @param	string	$db_name
	 * @return	string
	 */
	public function create_database($db_name)
	{
		// Firebird databases are flat files, so a path is required

		// Hostname is needed for remote access
		empty($this->db->hostname) OR $db_name = $this->hostname.':'.$db_name;

		return parent::create_database('"'.$db_name.'"');
	}

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

	/**
	 * Drop database
	 *
	 * @param	string	$db_name	(ignored)
	 * @return	bool
	 */
	public function drop_database($db_name = '')
	{
		if ( ! ibase_drop_db($this->conn_id))
		{
			return ($this->db->db_debug) ? $this->db->display_error('db_unable_to_drop') : FALSE;
		}
		elseif ( ! empty($this->db->data_cache['db_names']))
		{
			$key = array_search(strtolower($this->db->database), array_map('strtolower', $this->db->data_cache['db_names']), TRUE);
			if ($key !== FALSE)
			{
				unset($this->db->data_cache['db_names'][$key]);
			}
		}

		return TRUE;
	}

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

	/**
	 * 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('DROP', 'ADD'), TRUE))
		{
			return parent::_alter_table($alter_type, $table, $field);
		}

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

			if (isset($field[$i]['type']))
			{
				$sqls[] = $sql.' ALTER COLUMN '.$this->db->escape_identififers($field[$i]['name'])
					.' TYPE '.$field[$i]['type'].$field[$i]['length'];
			}

			if ( ! empty($field[$i]['default']))
			{
				$sqls[] = $sql.' ALTER COLUMN '.$this->db->escape_identifiers($field[$i]['name'])
					.' SET DEFAULT '.$field[$i]['default'];
			}

			if (isset($field[$i]['null']))
			{
				$sqls[] = 'UPDATE "RDB$RELATION_FIELDS" SET "RDB$NULL_FLAG" = '
					.($field[$i]['null'] === TRUE ? 'NULL' : '1')
					.' WHERE "RDB$FIELD_NAME" = '.$this->db->escape($field[$i]['name'])
					.' AND "RDB$RELATION_NAME" = '.$this->db->escape($table);
			}

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

		return $sqls;
 	}

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

	/**
	 * Process column
	 *
	 * @param	array	$field
	 * @return	string
	 */
	protected function _process_column($field)
	{
		return $this->db->escape_identifiers($field['name'])
			.' '.$field['type'].$field['length']
			.$field['null']
			.$field['unique']
			.$field['default'];
	}

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

	/**
	 * Field attribute TYPE
	 *
	 * Performs a data type mapping between different databases.
	 *
	 * @param	array	&$attributes
	 * @return	void
	 */
	protected function _attr_type(&$attributes)
	{
		switch (strtoupper($attributes['TYPE']))
		{
			case 'TINYINT':
				$attributes['TYPE'] = 'SMALLINT';
				$attributes['UNSIGNED'] = FALSE;
				return;
			case 'MEDIUMINT':
				$attributes['TYPE'] = 'INTEGER';
				$attributes['UNSIGNED'] = FALSE;
				return;
			case 'INT':
				$attributes['TYPE'] = 'INTEGER';
				return;
			case 'BIGINT':
				$attributes['TYPE'] = 'INT64';
				return;
			default: return;
		}
	}

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

	/**
	 * Field attribute AUTO_INCREMENT
	 *
	 * @param	array	&$attributes
	 * @param	array	&$field
	 * @return	void
	 */
	protected function _attr_auto_increment(&$attributes, &$field)
	{
		// Not supported
	}

}
