<?php
/**
 * This source file is part of the open source project
 * ExpressionEngine (https://expressionengine.com)
 *
 * @link      https://expressionengine.com/
 * @copyright Copyright (c) 2003-2022, Packet Tide, LLC (https://www.packettide.com)
 * @license   https://expressionengine.com/license Licensed under Apache License, Version 2.0
 */

/**
 * Router Class
 *
 * Parses URIs and determines routing
 */
class EE_Router
{
    public $config;
    public $routes = array();
    public $class = '';
    public $method = 'index';
    public $directory = '';
    public $default_controller;
    public $namespace_prefix = '';

    /**
     * Constructor
     *
     * Runs the route mapping function.
     */
    public function __construct()
    {
        $this->config = load_class('Config', 'core');
        $this->uri = load_class('URI', 'core');
        log_message('debug', "Router Class Initialized");
    }

    /**
     * Set the route mapping
     *
     * This function determines what should be served based on the URI request,
     * as well as any "routes" that have been set in the routing config file.
     *
     * @access	private
     * @return	void
     */
    public function _set_routing()
    {
        // Are query strings enabled in the config file?  Normally CI doesn't utilize query strings
        // since URI segments are more search-engine friendly, but they can optionally be used.
        // If this feature is enabled, we will gather the directory/class/method a little differently
        $segments = array();
        if ($this->config->item('enable_query_strings') === true and isset($_GET[$this->config->item('controller_trigger')])) {
            if (isset($_GET[$this->config->item('directory_trigger')])) {
                $this->set_directory(trim($this->uri->_filter_uri($_GET[$this->config->item('directory_trigger')])));
                $segments[] = rtrim($this->fetch_directory(), '/');
            }

            if (isset($_GET[$this->config->item('controller_trigger')])) {
                $this->set_class(trim($this->uri->_filter_uri($_GET[$this->config->item('controller_trigger')])));
                $segments[] = $this->fetch_class();
            }

            if (isset($_GET[$this->config->item('function_trigger')])) {
                $this->set_method(trim($this->uri->_filter_uri($_GET[$this->config->item('function_trigger')])));
                $segments[] = $this->fetch_method();
            }
        }

        // Load the routes.php file.
        if (defined('EE_APPPATH')) {
            require_once APPPATH . 'config/routes.php';
        } else {
            $route = $this->config->loadFile('routes');
        }

        $this->routes = (! isset($route) or ! is_array($route)) ? array() : $route;
        unset($route);

        // Set the default controller so we can display it in the event
        // the URI doesn't correlated to a valid controller.
        $this->default_controller = (! isset($this->routes['default_controller']) or $this->routes['default_controller'] == '') ? false : strtolower($this->routes['default_controller']);

        // Were there any query string segments?  If so, we'll validate them and bail out since we're done.
        if (count($segments) > 0) {
            return $this->_validate_request($segments);
        }

        // Fetch the complete URI string
        $this->uri->_fetch_uri_string();

        // Is there a URI string? If not, the default controller specified in the "routes" file will be shown.
        if ($this->uri->uri_string == '') {
            return $this->_set_default_controller();
        }

        // Do we need to remove the URL suffix?
        $this->uri->_remove_url_suffix();

        // Compile the segments into an array
        $this->uri->_explode_segments();

        // Parse any custom routing that may exist
        $this->_parse_routes();

        // Re-index the segment array so that it starts with 1 rather than 0
        $this->uri->_reindex_segments();
    }

    /**
     * Set the default controller
     *
     * @access	private
     * @return	void
     */
    public function _set_default_controller()
    {
        if ($this->default_controller === false) {
            show_error("Unable to determine what should be displayed. A default route has not been specified in the routing file.");
        }

        // Is the method being specified?
        if (strpos($this->default_controller, '/') !== false) {
            $x = explode('/', $this->default_controller);

            $this->set_class($x[0]);
            $this->set_method($x[1]);
            $this->_set_request($x);
        } else {
            $this->set_class($this->default_controller);
            $this->set_method('index');
            $this->_set_request(array($this->default_controller, 'index'));
        }

        // re-index the routed segments array so it starts with 1 rather than 0
        $this->uri->_reindex_segments();

        log_message('debug', "No URI present. Default controller set.");
    }

    /**
     * Set the Route
     *
     * This function takes an array of URI segments as
     * input, and sets the current class/method
     *
     * @access	private
     * @param	array
     * @param	bool
     * @return	void
     */
    public function _set_request($segments = array())
    {
        $segments = $this->_validate_request($segments);

        if (count($segments) == 0) {
            return $this->_set_default_controller();
        }

        $this->set_class($segments[0]);

        if (isset($segments[1])) {
            // A standard method request
            $this->set_method($segments[1]);
        } else {
            // This lets the "routed" segment array identify that the default
            // index method is being used.
            $segments[1] = 'index';
        }

        // Update our "routed" segment array to contain the segments.
        // Note: If there is no custom routing, this array will be
        // identical to $this->uri->segments
        $this->uri->rsegments = $segments;
    }

    /**
     * Validates the supplied segments.  Attempts to determine the path to
     * the controller.
     *
     * @access	private
     * @param	array
     * @param	boolean		$show_404	Set to FALSE to bypass the override
     * @return	array
     */
    public function _validate_request($segments, $override = true)
    {
        if (count($segments) == 0) {
            return $segments;
        }

        $last = end($segments);
        reset($segments);

        $c = 0;

        // First check for a namespaced situation
        $saved_segments = $segments;
        $directory = APPPATH . '../ExpressionEngine/Controller/';
        $namespace = '';
        if (strtolower($segments[0]) == 'cp') {
            array_shift($segments); // This will not factor into the path for namespaced stuff
            $c++;
        }

        while ($c < count($saved_segments)) {
            $segment = str_replace('-', '_', $segments[0]);
            $words = explode('_', $segment);
            $words = array_map('ucfirst', $words);
            $segment = implode('', $words);

            // Do we have a directory instead of a controller file?
            if (! file_exists($directory . $segment . '.php') && is_dir($directory . $segment)) {
                $directory .= $segment . '/';
                $namespace .= '\\' . $segment;
                array_shift($segments);
                $c++;

                continue;
            }

            // For organization purposes everything is in a subdirectory inside
            // .../Controllers/. Top level controllers may be structured thus:
            // .../Controllers/FooBar/FooBar.php
            // We now check for that eventuality. This is important because
            // the returned array assumes that the string at index 0 is the
            // controller class.
            if (! file_exists($directory . $segment . '.php')) {
                if ($c > 0) {
                    $segment = str_replace('-', '_', $saved_segments[$c - 1]);
                    $words = explode('_', $segment);
                    $words = array_map('ucfirst', $words);
                    $segment = implode('', $words);

                    if (file_exists($directory . $segment . '.php')) {
                        array_unshift($segments, $saved_segments[$c - 1]);
                    }
                }
            }

            break;
        }

        if ($namespace != '') {
            $this->set_directory($directory);
            $this->namespace_prefix = '\ExpressionEngine\Controller' . $namespace;

            // If the final segment is a directory check for a file matching the
            // directory's name inside the directory. Use its index method.
            if (empty($segments)) {
                $segment = str_replace('-', '_', $last);
                $words = explode('_', $segment);
                $words = array_map('ucfirst', $words);
                $segment = implode('', $words);

                if (file_exists($directory . $segment . '.php')) {
                    return array($last, 'index');
                }
            }

            return $segments;
        }

        $segments = $saved_segments;
        $c = 0;

        // Loop through our segments and return as soon as a controller
        // is found or when such a directory doesn't exist
        while ($c < count($saved_segments)) {
            $test = $this->directory . str_replace('-', '_', $segments[0]);

            // First lowercase
            if (! file_exists(APPPATH . 'controllers/' . $test . '.php') && is_dir(APPPATH . 'controllers/' . $this->directory . $segments[0])) {
                $this->set_directory(array_shift($segments), true);
                $c++;

                continue;
            }

            return $segments;
        }

        // If the final segment is a directory check for a file matching the
        // directory's name inside the directory. Use its index method.
        if (empty($segments)) {
            if (file_exists(APPPATH . 'controllers/' . $this->directory . $last . '.php')) {
                return array($last, 'index');
            }
        }

        // If we've gotten this far it means that the URI does not correlate to a valid
        // controller class.  We will now see if there is an override
        if ($override === true && isset($this->routes['404_override']) && $this->routes['404_override'] != '') {
            if (strpos($this->routes['404_override'], '/') !== false) {
                $x = $this->_validate_request(explode('/', $this->routes['404_override']), false);
                $x[1] = (empty($x[1])) ? 'index' : $x[1];

                $this->set_class($x[0]);
                $this->set_method($x[1]);

                return $x;
            }
        }

        // Nothing else to do at this point but show a 404
        show_error("The requested URL could not be found.", 404);
    }

    /**
     *  Parse Routes
     *
     * This function matches any routes that may exist in
     * the config/routes.php file against the URI to
     * determine if the class/method need to be remapped.
     *
     * @access	private
     * @return	void
     */
    public function _parse_routes()
    {
        // Turn the segment array into a URI string
        $uri = implode('/', $this->uri->segments);

        // Is there a literal match?  If so we're done
        if (isset($this->routes[$uri])) {
            return $this->_set_request(explode('/', $this->routes[$uri]));
        }

        // Loop through the route array looking for wild-cards
        foreach ($this->routes as $key => $val) {
            // Convert wild-cards to RegEx
            $key = str_replace(':any', '.+', str_replace(':num', '[0-9]+', $key));

            // Does the RegEx match?
            if (preg_match('#^' . $key . '$#', $uri)) {
                // Do we have a back-reference?
                if (strpos($val, '$') !== false and strpos($key, '(') !== false) {
                    $val = preg_replace('#^' . $key . '$#', $val, $uri);
                }

                return $this->_set_request(explode('/', $val));
            }
        }

        // If we got this far it means we didn't encounter a
        // matching route so we'll set the site default route
        $this->_set_request($this->uri->segments);
    }

    /**
     * Set the class name
     *
     * @access	public
     * @param	string
     * @return	void
     */
    public function set_class($class)
    {
        $this->class = str_replace(array('/', '.'), '', $class);
    }

    /**
     * Fetch the current class
     *
     * @access	public
     * @return	string
     */
    public function fetch_class($prepend_namespace = false)
    {
        $class = str_replace('-', '_', $this->class);

        // If we are in a namespaced controller the class is PascalCased
        if ($prepend_namespace && ! empty($this->namespace_prefix)) {
            $words = explode('_', $class);
            $words = array_map('ucfirst', $words);
            $class = implode('', $words);

            return $this->namespace_prefix . '\\' . $class;
        }

        return $class;
    }

    /**
     *  Set the method name
     *
     * @access	public
     * @param	string
     * @return	void
     */
    public function set_method($method)
    {
        $this->method = $method;
    }

    /**
     *  Fetch the current method
     *
     * @access	public
     * @return	string
     */
    public function fetch_method()
    {
        if ($this->method == $this->fetch_class()) {
            return 'index';
        }

        $method = str_replace('-', '_', $this->method);

        // If we are in a namespaced controller the method is camelCased
        if (! empty($this->namespace_prefix)) {
            $words = explode('_', $method);
            $method = strtolower(array_shift($words));
            $words = array_map('ucfirst', $words);
            $method .= implode('', $words);
        }

        return $method;
    }

    /**
     *  Set the directory name
     *
     * @param	string	$dir	Directory name
     * @param	bool	$appent Whether we're appending rather then setting the full value
     * @return	void
     */
    public function set_directory($dir, $append = false)
    {
        if ($append !== true or empty($this->directory)) {
            $this->directory = str_replace('.', '', trim($dir, '/')) . '/';
        } else {
            $this->directory .= str_replace('.', '', trim($dir, '/')) . '/';
        }
    }

    /**
     *  Fetch the sub-directory (if any) that contains the requested controller class
     *
     * @access	public
     * @return	string
     */
    public function fetch_directory()
    {
        return $this->directory;
    }

    /**
     *  Set the controller overrides
     *
     * @access	public
     * @param	array
     * @return	null
     */
    public function _set_overrides($routing)
    {
        if (! is_array($routing)) {
            return;
        }

        if (isset($routing['directory'])) {
            $this->set_directory($routing['directory']);
        }

        if (isset($routing['controller']) and $routing['controller'] != '') {
            $this->set_class($routing['controller']);
        }

        if (isset($routing['function'])) {
            $routing['function'] = ($routing['function'] == '') ? 'index' : $routing['function'];
            $this->set_method($routing['function']);
        }
    }
}
// END Router Class

// EOF
