<?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 1.4.1
 * @filesource
 */

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

/**
 * Oracle Forge Class
 *
 * @category    Database
 * @author      EllisLab Dev Team
 * @link        https://codeigniter.com/userguide3/database/
 */
class CI_DB_oci8_forge extends CI_DB_forge
{
    /**
     * CREATE DATABASE statement
     *
     * @var string
     */
    protected $_create_database = false;

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

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

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

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

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

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

    /**
     * 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'])
                        . ' TO ' . $this->db->escape_identifiers($field[$i]['new_name']);
                }

                $field[$i] = "\n\t" . $field[$i]['_literal'];
            }
        }

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

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

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

    /**
     * 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'], 'number') !== false && version_compare($this->db->version(), '12.1', '>=')) {
            $field['auto_increment'] = ' GENERATED ALWAYS AS IDENTITY';
        }
    }

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

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

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

    /**
     * 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'] = 'NUMBER';
                return;
            case 'MEDIUMINT':
                $attributes['TYPE'] = 'NUMBER';
                return;
            case 'INT':
                $attributes['TYPE'] = 'NUMBER';
                return;
            case 'BIGINT':
                $attributes['TYPE'] = 'NUMBER';
                return;
            default:
                return;
        }
    }
}