<?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');

/**
 * Postgre Forge Class
 *
 * @package     CodeIgniter
 * @subpackage  Drivers
 * @category    Database
 * @author      EllisLab Dev Team
 * @link        https://codeigniter.com/userguide3/database/
 */
class CI_DB_postgre_forge extends CI_DB_forge
{
    /**
     * UNSIGNED support
     *
     * @var array
     */
    protected $_unsigned        = array(
        'INT2'      => 'INTEGER',
        'SMALLINT'  => 'INTEGER',
        'INT'       => 'BIGINT',
        'INT4'      => 'BIGINT',
        'INTEGER'   => 'BIGINT',
        'INT8'      => 'NUMERIC',
        'BIGINT'    => 'NUMERIC',
        'REAL'      => 'DOUBLE PRECISION',
        'FLOAT'     => 'DOUBLE PRECISION'
    );

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

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

    /**
     * Class constructor
     *
     * @param   object  &$db    Database object
     * @return  void
     */
    public function __construct(&$db)
    {
        parent::__construct($db);

        if (version_compare($this->db->version(), '9.0', '>')) {
            $this->create_table_if = 'CREATE TABLE IF NOT EXISTS';
        }
    }

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

    /**
     * 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 (version_compare($this->db->version(), '8', '>=') && isset($field[$i]['type'])) {
                $sqls[] = $sql . ' ALTER COLUMN ' . $this->db->escape_identifiers($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 ' . $field[$i]['default'];
            }

            if (isset($field[$i]['null'])) {
                $sqls[] = $sql . ' ALTER COLUMN ' . $this->db->escape_identifiers($field[$i]['name'])
                    . (trim($field[$i]['null']) === $this->_null ? ' DROP NOT NULL' : ' SET NOT NULL');
            }

            if (! 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']);
            }

            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'];
            }
        }

        return $sqls;
    }

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

    /**
     * Field attribute TYPE
     *
     * Performs a data type mapping between different databases.
     *
     * @param   array   &$attributes
     * @return  void
     */
    protected function _attr_type(&$attributes)
    {
        // Reset field lengths for data types that don't support it
        if (isset($attributes['CONSTRAINT']) && stripos($attributes['TYPE'], 'int') !== false) {
            $attributes['CONSTRAINT'] = null;
        }

        switch (strtoupper($attributes['TYPE'])) {
            case 'TINYINT':
                $attributes['TYPE'] = 'SMALLINT';
                $attributes['UNSIGNED'] = false;
                return;
            case 'MEDIUMINT':
                $attributes['TYPE'] = 'INTEGER';
                $attributes['UNSIGNED'] = false;
                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) {
            $field['type'] = ($field['type'] === 'NUMERIC')
                ? 'BIGSERIAL'
                : 'SERIAL';
        }
    }
}