<?php

/**
 * CodeIgniter
 *
 * An open source application development framework for PHP
 *
 * This content is released under the MIT License (MIT)
 *
 * Copyright (c) 2014 - 2017, 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. (https://ellislab.com/)
 * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
 * @license	http://opensource.org/licenses/MIT	MIT License
 * @link	https://codeigniter.com
 * @since	Version 1.0.0
 * @filesource
 */
defined('BASEPATH') OR exit('No direct script access allowed');

/**
 * Initialize the database
 *
 * @category	Database
 * @author	EllisLab Dev Team
 * @link	https://codeigniter.com/user_guide/database/
 *
 * @param 	string|string[]	$params
 * @param 	bool		$query_builder_override
 * 				Determines if query builder should be used or not
 */
function &DB($params = '', $query_builder_override = NULL) {
    // Load the DB config file if a DSN string wasn't passed
    if (is_string($params) && strpos($params, '://') === FALSE) {
        // Is the config file in the environment folder?
        if (!file_exists($file_path = APPPATH . 'config/' . ENVIRONMENT . '/database.php') && !file_exists($file_path = APPPATH . 'config/database.php')) {
            show_error('The configuration file database.php does not exist.');
        }

        include($file_path);

        // Make packages contain database config files,
        // given that the controller instance already exists
        if (class_exists('CI_Controller', FALSE)) {
            foreach (get_instance()->load->get_package_paths() as $path) {
                if ($path !== APPPATH) {
                    if (file_exists($file_path = $path . 'config/' . ENVIRONMENT . '/database.php')) {
                        include($file_path);
                    } elseif (file_exists($file_path = $path . 'config/database.php')) {
                        include($file_path);
                    }
                }
            }
        }

        if (!isset($db) OR count($db) === 0) {
            show_error('No database connection settings were found in the database config file.');
        }

        if ($params !== '') {
            $active_group = $params;
        }

        if (!isset($active_group)) {
            show_error('You have not specified a database connection group via $active_group in your config/database.php file.');
        } elseif (!isset($db[$active_group])) {
            show_error('You have specified an invalid database connection group (' . $active_group . ') in your config/database.php file.');
        }

        $params = $db[$active_group];
    } elseif (is_string($params)) {
        /**
         * Parse the URL from the DSN string
         * Database settings can be passed as discreet
         * parameters or as a data source name in the first
         * parameter. DSNs must have this prototype:
         * $dsn = 'driver://username:password@hostname/database';
         */
        if (($dsn = @parse_url($params)) === FALSE) {
            show_error('Invalid DB Connection String');
        }

        $params = array(
            'dbdriver' => $dsn['scheme'],
            'hostname' => isset($dsn['host']) ? rawurldecode($dsn['host']) : '',
            'port' => isset($dsn['port']) ? rawurldecode($dsn['port']) : '',
            'username' => isset($dsn['user']) ? rawurldecode($dsn['user']) : '',
            'password' => isset($dsn['pass']) ? rawurldecode($dsn['pass']) : '',
            'database' => isset($dsn['path']) ? rawurldecode(substr($dsn['path'], 1)) : ''
        );

        // Were additional config items set?
        if (isset($dsn['query'])) {
            parse_str($dsn['query'], $extra);

            foreach ($extra as $key => $val) {
                if (is_string($val) && in_array(strtoupper($val), array('TRUE', 'FALSE', 'NULL'))) {
                    $val = var_export($val, TRUE);
                }

                $params[$key] = $val;
            }
        }
    }

    // No DB specified yet? Beat them senseless...
    if (empty($params['dbdriver'])) {
        show_error('You have not selected a database type to connect to.');
    }

    // Load the DB classes. Note: Since the query builder class is optional
    // we need to dynamically create a class that extends proper parent class
    // based on whether we're using the query builder class or not.
    if ($query_builder_override !== NULL) {
        $query_builder = $query_builder_override;
    }
    // Backwards compatibility work-around for keeping the
    // $active_record config variable working. Should be
    // removed in v3.1
    elseif (!isset($query_builder) && isset($active_record)) {
        $query_builder = $active_record;
    }

    require_once(BASEPATH . 'database/DB_driver.php');

    if (!isset($query_builder) OR $query_builder === TRUE) {
        require_once(BASEPATH . 'database/DB_query_builder.php');
        if (!class_exists('CI_DB', FALSE)) {

            /**
             * CI_DB
             *
             * Acts as an alias for both CI_DB_driver and CI_DB_query_builder.
             *
             * @see	CI_DB_query_builder
             * @see	CI_DB_driver
             */
            class CI_DB extends CI_DB_query_builder {
                
            }

        }
    } elseif (!class_exists('CI_DB', FALSE)) {

        /**
         * @ignore
         */
        class CI_DB extends CI_DB_driver {
            
        }

    }

    // Load the DB driver
    $driver_file = BASEPATH . 'database/drivers/' . $params['dbdriver'] . '/' . $params['dbdriver'] . '_driver.php';

    file_exists($driver_file) OR show_error('Invalid DB driver');
    require_once($driver_file);

    // Instantiate the DB adapter
    $driver = 'CI_DB_' . $params['dbdriver'] . '_driver';
    $DB = new $driver($params);

    // Check for a subdriver
    if (!empty($DB->subdriver)) {
        $driver_file = BASEPATH . 'database/drivers/' . $DB->dbdriver . '/subdrivers/' . $DB->dbdriver . '_' . $DB->subdriver . '_driver.php';

        if (file_exists($driver_file)) {
            require_once($driver_file);
            $driver = 'CI_DB_' . $DB->dbdriver . '_' . $DB->subdriver . '_driver';
            $DB = new $driver($params);
        }
    }

    $DB->initialize();
    return $DB;
}
