univ-pau-ics/build/router/core/Router.php

<?php

	/**************************
	*          Router         *
	*        08-12-2016       *
	***************************
	* Designed & Developed by *
	*      xdrm-brackets      *
	***************************
	*    https://xdrm.io/     *
	**************************/

	use \router\core\ControllerFactory;

	namespace router\core;

	class Router{



		/* [1] Attributes
		=========================================================*/
		private $url;          // current URL
		private $cnf;          // parsed configuration
		private $http_methods; // allowed HTTP methods
		private $routes;       // built routes


		/* [2] Configuration file
		=========================================================*/
		private static function config_path(){ return __CONFIG__.'/routes.json'; }

		// Get random token
		public static function randBoundary(){ return dechex( random_int((int) 1e10, (int) 1e20) ); }


		// Instance getter
		public static function launch($url=null){
			/* (1) Instanciate the 	router (propagation) */
			$instance = new Router($url);


			/* (2) Launches the router */
			$instance->run();

		}


		/* [3] Constructor
		*
		* @url<String> 											Current URL
		*
		* @return instance<Router> 								Instance du routeur
		*
		=========================================================*/
		public function __construct($url=null){
			/* (1) Checks arguments
			---------------------------------------------------------*/
			/* (1) Default value if incorrect */
			$this->url = is_string($url) ? $url : '';

			/* (2) Add first '/' if missing */
			if( !preg_match('/^\//', $url) )
				$this->url = '/'.$this->url;


			/* (2) Loads configuration
			---------------------------------------------------------*/
			/* (1) Tries to load configuration */
			$this->cnf = self::loadConfig();

			/* (2) If error occurs, throw Exception */
			if( is_null($this->cnf) )
				throw new \Exception("[Router] Configuration file error found");


			/* (3) Set allowed HTTP methods
			---------------------------------------------------------*/
			/* (1) If not defined */
			if( !isset($this->cnf['methods']) )
				throw new \Exception('[Router] Configuration file error, \'methods\' clause missing');

			/* (2) Try to clean methods */
			$this->http_methods = self::cleanMethods($this->cnf['methods']);

			/* (3) Manage error */
			if( is_null($this->http_methods) )
				throw new \Exception('[Router] Configuration file error. \'methods\' must be an array of HTTP methods ["GET", "POST", ...]');


			/* (4) Initialize routes
			---------------------------------------------------------*/
			/* (1) Init routes */
			$this->routes = [];

			foreach($this->http_methods as $method)
				$this->routes[$method] = [];

			/* (2) Default configuration if missing */
			if( !isset($this->cnf['routes']) || !is_array($this->cnf['routes']) )
				$this->cnf['routes'] = [];


			/* (5) Loads each route
			---------------------------------------------------------*/
			foreach($this->cnf['routes'] as $pattern=>$route){

				/* (1) If missing (required) parameters */
				if( !isset($route['controller']) )
					continue;

				/* (2) Default value for 'methods' */
				( !isset($route['methods']) || !is_array($route['methods']) ) && ($route['methods'] = $this->http_methods);

				/* (3) Default value for 'arguments' */
				( !isset($route['arguments']) || !is_array($route['arguments']) ) && ($route['arguments'] = []);

				/* (4) Add route */
				$added = $this->add($pattern, $route['controller'], $route['arguments']);

				// if error -> next
				if( $added === false )
					continue;


				/* (5) Add route for each method */
				foreach($route['methods'] as $method)
					if( in_array($method, $this->http_methods) )
						$this->routes[$method][] = $added;

			}


		}




		/* [4] Adds a route
		*
		* @pattern<String> 												URL pattern with {somevar} variables within
		* @controller<String> 											Controller name + method "controllername:methodname"
		* @arguments<Array> 											List of pattern's arguments and their RegExp composition (default is alphanumeric)
		*
		* @return route<Route>											New instance of Route || false on error
		*
		=========================================================*/
		public function add($pattern=null, $controller=null, $arguments=[]){

			/* (1) Format and check pattern
			---------------------------------------------------------*/
			/* (1) If not a string */
			if( !is_string($pattern) )
				return false;

			/* (2) Format pattern and check result */
			$pattern = self::formatPattern($pattern, $arguments);

			if( $pattern === false )
				return false;


			/* (2) Check controller
			---------------------------------------------------------*/
			/* (1) Check default type */
			if( !is_string($controller) || !preg_match('/^([A-Za-z_]\w+):([A-Za-z_]\w+)$/', $controller, $c_matches) )
				return false;

			/* (2) Check existence */
			if( !ControllerFactory::checkController($c_matches[1]) )
				return false;


			/* (3) Check method
			---------------------------------------------------------*/
			if( !method_exists('\\router\\controller\\'.$c_matches[1], $c_matches[2]) )
				return false;


			/* (4) Return new route
			---------------------------------------------------------*/
			return new Route($pattern, $c_matches[1], $c_matches[2]);
		}




		/* [5] Router launch
		*
		=========================================================*/
		public function run(){
			/* (1) Manage HTTP method
			---------------------------------------------------------*/
			/* (1) Fetch HTTP method */
			$httpMethod = $_SERVER['REQUEST_METHOD'];

			/* (2) If no route for this -> exit */
			if( !isset($this->routes[$httpMethod]) || count($this->routes[$httpMethod]) <= 0 )
				return false;


			/* (2) Manage routes (matching)
			---------------------------------------------------------*/
			/* (1) Check for each HTTP method's route */
			foreach($this->routes[$httpMethod] as $route)

				/* (2) First route that matches -> call & return response */
				if( $route->match($this->url) )
					return $route->call();


			/* (3) If no route found -> return false
			---------------------------------------------------------*/
			return false;
		}


		/* FORMATS A PATTERN
		*
		* @pattern<String> 										Pattern to process on
		* @arguments<Array> 									List of used arguments, with regex if given
		* @vars<Boolean>										[OPT] If variable replacement have to be done
		*
		* @return formatted<String> 							Formatted pattern || false on error
		*
		*/
		public static function formatPattern($pattern, $arguments=[]){

			/* (1) Check arguments
			---------------------------------------------------------*/
			/* (1) Check minimal length */
			if( strlen($pattern) < 1 )
				return false;

			/* (2) Arguments formatting */
			$arguments = !is_array($arguments) ? [] : $arguments;


			/* (2) Replace special characters + replace vars
			---------------------------------------------------------*/
			/* (1) Check default URL format */
			if( !preg_match('/^(\/[\w\{\}-]*)*\/?$/', $pattern) )
				return false;

			/* (2) Escape special characters */
			$pattern = str_replace('/', '\\/', $pattern);

			/* (3) Add optional ending '/' */
			if( !preg_match('/\/$/', $pattern) )
				$pattern .= '\\/?';

			/* (4) Replace variable by tagged capturing groups */
			$boundary = self::randBoundary();
			$pattern = preg_replace('/\{([a-z_][a-z0-9_]*)\}/i', '(?P<$1>'.$boundary.'-$1-'.$boundary.')', $pattern);


			/* (3) Variable replacement
			---------------------------------------------------------*/
			/* (1) List variables */
			$vars = [];
			$var_pattern = '/'.$boundary.'\-([A-Za-z_][A-Za-z0-9_]*)\-'.$boundary.'/';
			preg_match_all($var_pattern, $pattern, $matches);

			/* (2) For each matching variable -> replace with associated regex */
			if( is_array($matches) && isset($matches[1]) ){

				foreach($matches[1] as $m=>$varname){

					// {3.1.1} Not in @arguments -> default regex  //
					if( !isset($arguments[$varname]) || !is_string($arguments[$varname]) ){
						$pattern = str_replace($matches[0][$m], '[A-Za-z0-9_]+', $pattern);
						continue;
					}

					// {3.1.2} If variable in @arguments -> set regex without capturing-groups //
					// $without_capg = str_replace('(', '(?:', $arguments[$varname]);
					$pattern = str_replace($matches[0][$m], $arguments[$varname], $pattern);

				}

			}


			/* (4) Return formatted pattern
			---------------------------------------------------------*/
			return $pattern;
		}



		/* LOADS CONFIGURATION
		*
		* @return cnf<Array> 								Configuration content || NULL if error
		*
		*/
		private static function loadConfig(){
			/* (1) Set configuration file's path */
			$cnfpath = self::config_path();

			/* (2) Checks file */
			if( !file_exists($cnfpath) )
				return null; // throw new \Exception("[Router] Configuration file not found");

			/* (3) Checks format -> null if error */
			return json_decode( file_get_contents($cnfpath), true );

		}


		/* CHECKS METHODS AND CLEAN THE LIST IF CORRECT
		*
		* @wanted<Array> 										List of wanted methods
		*
		* @return cleaned<Array> 								Cleaned methods || null if error
		*
		*/
		private static function cleanMethods($wanted=[]){
			/* (1) Checks @wanted */
			if( !is_array($wanted) || count($wanted) < 1 )
				return null; // throw new \Exception('[Router] Configuration file error, \'methods\' must be an array containing managed HTTP methods');

			/* (2) Set methods (uppercase and unique) */
			$cleaned = [];

			foreach($wanted as $method)
				if( !in_array(strtoupper($method), $cleaned) )
					$cleaned[] = strtoupper($method);

			/* (3) Return cleaned method list */
			return $cleaned;
		}

	}