<?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');

/**
 * URI Class
 *
 * Parses URIs and determines routing
 *
 * @package		CodeIgniter
 * @subpackage	Libraries
 * @category	URI
 * @author		EllisLab Dev Team
 * @link		https://codeigniter.com/user_guide/libraries/uri.html
 */
class CI_URI {

    /**
     * List of cached URI segments
     *
     * @var	array
     */
    public $keyval = array();

    /**
     * Current URI string
     *
     * @var	string
     */
    public $uri_string = '';

    /**
     * List of URI segments
     *
     * Starts at 1 instead of 0.
     *
     * @var	array
     */
    public $segments = array();

    /**
     * List of routed URI segments
     *
     * Starts at 1 instead of 0.
     *
     * @var	array
     */
    public $rsegments = array();

    /**
     * Permitted URI chars
     *
     * PCRE character group allowed in URI segments
     *
     * @var	string
     */
    protected $_permitted_uri_chars;

    /**
     * Class constructor
     *
     * @return	void
     */
    public function __construct() {
        $this->config = & load_class('Config', 'core');

        // If query strings are enabled, we don't need to parse any segments.
        // However, they don't make sense under CLI.
        if (is_cli() OR $this->config->item('enable_query_strings') !== TRUE) {
            $this->_permitted_uri_chars = $this->config->item('permitted_uri_chars');

            // If it's a CLI request, ignore the configuration
            if (is_cli()) {
                $uri = $this->_parse_argv();
            } else {
                $protocol = $this->config->item('uri_protocol');
                empty($protocol) && $protocol = 'REQUEST_URI';

                switch ($protocol) {
                    case 'AUTO': // For BC purposes only
                    case 'REQUEST_URI':
                        $uri = $this->_parse_request_uri();
                        break;
                    case 'QUERY_STRING':
                        $uri = $this->_parse_query_string();
                        break;
                    case 'PATH_INFO':
                    default:
                        $uri = isset($_SERVER[$protocol]) ? $_SERVER[$protocol] : $this->_parse_request_uri();
                        break;
                }
            }

            $this->_set_uri_string($uri);
        }

        log_message('info', 'URI Class Initialized');
    }

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

    /**
     * Set URI String
     *
     * @param 	string	$str
     * @return	void
     */
    protected function _set_uri_string($str) {
        // Filter out control characters and trim slashes
        $this->uri_string = trim(remove_invisible_characters($str, FALSE), '/');

        if ($this->uri_string !== '') {
            // Remove the URL suffix, if present
            if (($suffix = (string) $this->config->item('url_suffix')) !== '') {
                $slen = strlen($suffix);

                if (substr($this->uri_string, -$slen) === $suffix) {
                    $this->uri_string = substr($this->uri_string, 0, -$slen);
                }
            }

            $this->segments[0] = NULL;
            // Populate the segments array
            foreach (explode('/', trim($this->uri_string, '/')) as $val) {
                $val = trim($val);
                // Filter segments for security
                $this->filter_uri($val);

                if ($val !== '') {
                    $this->segments[] = $val;
                }
            }

            unset($this->segments[0]);
        }
    }

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

    /**
     * Parse REQUEST_URI
     *
     * Will parse REQUEST_URI and automatically detect the URI from it,
     * while fixing the query string if necessary.
     *
     * @return	string
     */
    protected function _parse_request_uri() {
        if (!isset($_SERVER['REQUEST_URI'], $_SERVER['SCRIPT_NAME'])) {
            return '';
        }

        // parse_url() returns false if no host is present, but the path or query string
        // contains a colon followed by a number
        $uri = parse_url('http://dummy' . $_SERVER['REQUEST_URI']);
        $query = isset($uri['query']) ? $uri['query'] : '';
        $uri = isset($uri['path']) ? $uri['path'] : '';

        if (isset($_SERVER['SCRIPT_NAME'][0])) {
            if (strpos($uri, $_SERVER['SCRIPT_NAME']) === 0) {
                $uri = (string) substr($uri, strlen($_SERVER['SCRIPT_NAME']));
            } elseif (strpos($uri, dirname($_SERVER['SCRIPT_NAME'])) === 0) {
                $uri = (string) substr($uri, strlen(dirname($_SERVER['SCRIPT_NAME'])));
            }
        }

        // This section ensures that even on servers that require the URI to be in the query string (Nginx) a correct
        // URI is found, and also fixes the QUERY_STRING server var and $_GET array.
        if (trim($uri, '/') === '' && strncmp($query, '/', 1) === 0) {
            $query = explode('?', $query, 2);
            $uri = $query[0];
            $_SERVER['QUERY_STRING'] = isset($query[1]) ? $query[1] : '';
        } else {
            $_SERVER['QUERY_STRING'] = $query;
        }

        parse_str($_SERVER['QUERY_STRING'], $_GET);

        if ($uri === '/' OR $uri === '') {
            return '/';
        }

        // Do some final cleaning of the URI and return it
        return $this->_remove_relative_directory($uri);
    }

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

    /**
     * Parse QUERY_STRING
     *
     * Will parse QUERY_STRING and automatically detect the URI from it.
     *
     * @return	string
     */
    protected function _parse_query_string() {
        $uri = isset($_SERVER['QUERY_STRING']) ? $_SERVER['QUERY_STRING'] : @getenv('QUERY_STRING');

        if (trim($uri, '/') === '') {
            return '';
        } elseif (strncmp($uri, '/', 1) === 0) {
            $uri = explode('?', $uri, 2);
            $_SERVER['QUERY_STRING'] = isset($uri[1]) ? $uri[1] : '';
            $uri = $uri[0];
        }

        parse_str($_SERVER['QUERY_STRING'], $_GET);

        return $this->_remove_relative_directory($uri);
    }

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

    /**
     * Parse CLI arguments
     *
     * Take each command line argument and assume it is a URI segment.
     *
     * @return	string
     */
    protected function _parse_argv() {
        $args = array_slice($_SERVER['argv'], 1);
        return $args ? implode('/', $args) : '';
    }

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

    /**
     * Remove relative directory (../) and multi slashes (///)
     *
     * Do some final cleaning of the URI and return it, currently only used in self::_parse_request_uri()
     *
     * @param	string	$uri
     * @return	string
     */
    protected function _remove_relative_directory($uri) {
        $uris = array();
        $tok = strtok($uri, '/');
        while ($tok !== FALSE) {
            if ((!empty($tok) OR $tok === '0') && $tok !== '..') {
                $uris[] = $tok;
            }
            $tok = strtok('/');
        }

        return implode('/', $uris);
    }

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

    /**
     * Filter URI
     *
     * Filters segments for malicious characters.
     *
     * @param	string	$str
     * @return	void
     */
    public function filter_uri(&$str) {
        if (!empty($str) && !empty($this->_permitted_uri_chars) && !preg_match('/^[' . $this->_permitted_uri_chars . ']+$/i' . (UTF8_ENABLED ? 'u' : ''), $str)) {
            show_error('The URI you submitted has disallowed characters.', 400);
        }
    }

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

    /**
     * Fetch URI Segment
     *
     * @see		CI_URI::$segments
     * @param	int		$n		Index
     * @param	mixed		$no_result	What to return if the segment index is not found
     * @return	mixed
     */
    public function segment($n, $no_result = NULL) {
        return isset($this->segments[$n]) ? $this->segments[$n] : $no_result;
    }

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

    /**
     * Fetch URI "routed" Segment
     *
     * Returns the re-routed URI segment (assuming routing rules are used)
     * based on the index provided. If there is no routing, will return
     * the same result as CI_URI::segment().
     *
     * @see		CI_URI::$rsegments
     * @see		CI_URI::segment()
     * @param	int		$n		Index
     * @param	mixed		$no_result	What to return if the segment index is not found
     * @return	mixed
     */
    public function rsegment($n, $no_result = NULL) {
        return isset($this->rsegments[$n]) ? $this->rsegments[$n] : $no_result;
    }

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

    /**
     * URI to assoc
     *
     * Generates an associative array of URI data starting at the supplied
     * segment index. For example, if this is your URI:
     *
     * 	example.com/user/search/name/joe/location/UK/gender/male
     *
     * You can use this method to generate an array with this prototype:
     *
     * 	array (
     * 		name => joe
     * 		location => UK
     * 		gender => male
     * 	 )
     *
     * @param	int	$n		Index (default: 3)
     * @param	array	$default	Default values
     * @return	array
     */
    public function uri_to_assoc($n = 3, $default = array()) {
        return $this->_uri_to_assoc($n, $default, 'segment');
    }

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

    /**
     * Routed URI to assoc
     *
     * Identical to CI_URI::uri_to_assoc(), only it uses the re-routed
     * segment array.
     *
     * @see		CI_URI::uri_to_assoc()
     * @param 	int	$n		Index (default: 3)
     * @param 	array	$default	Default values
     * @return 	array
     */
    public function ruri_to_assoc($n = 3, $default = array()) {
        return $this->_uri_to_assoc($n, $default, 'rsegment');
    }

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

    /**
     * Internal URI-to-assoc
     *
     * Generates a key/value pair from the URI string or re-routed URI string.
     *
     * @used-by	CI_URI::uri_to_assoc()
     * @used-by	CI_URI::ruri_to_assoc()
     * @param	int	$n		Index (default: 3)
     * @param	array	$default	Default values
     * @param	string	$which		Array name ('segment' or 'rsegment')
     * @return	array
     */
    protected function _uri_to_assoc($n = 3, $default = array(), $which = 'segment') {
        if (!is_numeric($n)) {
            return $default;
        }

        if (isset($this->keyval[$which], $this->keyval[$which][$n])) {
            return $this->keyval[$which][$n];
        }

        $total_segments = "total_{$which}s";
        $segment_array = "{$which}_array";

        if ($this->$total_segments() < $n) {
            return (count($default) === 0) ? array() : array_fill_keys($default, NULL);
        }

        $segments = array_slice($this->$segment_array(), ($n - 1));
        $i = 0;
        $lastval = '';
        $retval = array();
        foreach ($segments as $seg) {
            if ($i % 2) {
                $retval[$lastval] = $seg;
            } else {
                $retval[$seg] = NULL;
                $lastval = $seg;
            }

            $i++;
        }

        if (count($default) > 0) {
            foreach ($default as $val) {
                if (!array_key_exists($val, $retval)) {
                    $retval[$val] = NULL;
                }
            }
        }

        // Cache the array for reuse
        isset($this->keyval[$which]) OR $this->keyval[$which] = array();
        $this->keyval[$which][$n] = $retval;
        return $retval;
    }

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

    /**
     * Assoc to URI
     *
     * Generates a URI string from an associative array.
     *
     * @param	array	$array	Input array of key/value pairs
     * @return	string	URI string
     */
    public function assoc_to_uri($array) {
        $temp = array();
        foreach ((array) $array as $key => $val) {
            $temp[] = $key;
            $temp[] = $val;
        }

        return implode('/', $temp);
    }

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

    /**
     * Slash segment
     *
     * Fetches an URI segment with a slash.
     *
     * @param	int	$n	Index
     * @param	string	$where	Where to add the slash ('trailing' or 'leading')
     * @return	string
     */
    public function slash_segment($n, $where = 'trailing') {
        return $this->_slash_segment($n, $where, 'segment');
    }

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

    /**
     * Slash routed segment
     *
     * Fetches an URI routed segment with a slash.
     *
     * @param	int	$n	Index
     * @param	string	$where	Where to add the slash ('trailing' or 'leading')
     * @return	string
     */
    public function slash_rsegment($n, $where = 'trailing') {
        return $this->_slash_segment($n, $where, 'rsegment');
    }

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

    /**
     * Internal Slash segment
     *
     * Fetches an URI Segment and adds a slash to it.
     *
     * @used-by	CI_URI::slash_segment()
     * @used-by	CI_URI::slash_rsegment()
     *
     * @param	int	$n	Index
     * @param	string	$where	Where to add the slash ('trailing' or 'leading')
     * @param	string	$which	Array name ('segment' or 'rsegment')
     * @return	string
     */
    protected function _slash_segment($n, $where = 'trailing', $which = 'segment') {
        $leading = $trailing = '/';

        if ($where === 'trailing') {
            $leading = '';
        } elseif ($where === 'leading') {
            $trailing = '';
        }

        return $leading . $this->$which($n) . $trailing;
    }

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

    /**
     * Segment Array
     *
     * @return	array	CI_URI::$segments
     */
    public function segment_array() {
        return $this->segments;
    }

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

    /**
     * Routed Segment Array
     *
     * @return	array	CI_URI::$rsegments
     */
    public function rsegment_array() {
        return $this->rsegments;
    }

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

    /**
     * Total number of segments
     *
     * @return	int
     */
    public function total_segments() {
        return count($this->segments);
    }

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

    /**
     * Total number of routed segments
     *
     * @return	int
     */
    public function total_rsegments() {
        return count($this->rsegments);
    }

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

    /**
     * Fetch URI string
     *
     * @return	string	CI_URI::$uri_string
     */
    public function uri_string() {
        return $this->uri_string;
    }

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

    /**
     * Fetch Re-routed URI string
     *
     * @return	string
     */
    public function ruri_string() {
        return ltrim(load_class('Router', 'core')->directory, '/') . implode('/', $this->rsegments);
    }

}
