<?php
namespace App\Core\Routing;
use App\Core\Request;
class Router
{
private Request $request; # Stores the current request object
private array $routes; # Stores all the defined routes
private ?array $currentRoute; # Stores the current matched route, if any
const NAMESPACE = 'App\Controllers\\'; # Controller namespace for routing
/**
* Router constructor.
* Initializes the request object and fetches the defined routes.
* Attempts to match the current request to a route.
*/
public function __construct()
{
$this->request = new Request(); # Instantiate the Request object
$this->routes = Route::routers(); # Fetch all defined routes
$this->currentRoute = $this->findRoute($this->request) ?? null; # Find the matching route or set to null
}
/**
* Find a matching route for the given request.
*
* @param Request $request The current request
* @return array|null The matched route or null if no match
*/
private function findRoute(Request $request): array|null
{
foreach ($this->routes as $route) {
# Match the HTTP method
if ($request->method() == $route['method']) {
# Check for dynamic parameters in the URI
if (str_contains($route['uri'], '{')) {
# Create a regex pattern to match dynamic parameters in the URI
$pattern = "/^" . str_replace(['/', '{', '}'], ['\/', '(?<', '>[a-zA-Z0-9-]+)'], $route['uri']) . "$/";
if (preg_match($pattern, $request->uri(), $matches)) {
# Add dynamic parameters to the request
foreach ($matches as $key => $value) {
if (is_string($key) && is_string($value)) {
$request->addParam($key, $value);
}
}
return $route; # Return the matched route
}
} else {
# Exact URI match
if ($request->uri() == $route['uri']) {
return $route; # Return the matched route
}
}
}
}
return null; # Return null if no route matches
}
/**
* Check if the request has a valid URI but an invalid method (405 Method Not Allowed).
*
* @param Request $request The current request
* @return bool True if the URI is found but the method is invalid
*/
private function invalidRequest(Request $request): bool
{
$foundRoute = false;
foreach ($this->routes as $route) {
# Convert route URI patterns to regex
$pattern = preg_replace('/\{([a-zA-Z_]+)\}/', '([a-zA-Z0-9-]+)', $route['uri']);
if (preg_match("#^$pattern$#", $request->uri())) {
if ($request->method() != $route['method']) {
$foundRoute = true; # URI found but method does not match
}
}
}
return $foundRoute; # Return true if method mismatch is found
}
/**
* Dispatch the matched route.
*
* @throws \Exception If the class or method does not exist
*/
private function dispatch(): void
{
$action = $this->currentRoute['action'];
if (is_null($action) || empty($action)) {
return; # If no action is defined, return early
}
if (is_callable($action)) {
$action(); # Execute callable actions
}
if (is_string($action)) {
$action = explode('@', $action); # Split controller and method by '@'
$action[0] = self::NAMESPACE . $action[0]; # Prepend the namespace to the controller
}
if (is_array($action)) {
$className = $action[0];
$methodName = $action[1];
# Throw an exception if the class does not exist
if (!class_exists($className)) {
throw new \Exception("Class '$className' Not Exists");
}
$controller = new $className(); # Instantiate the controller
# Throw an exception if the method does not exist
if (!method_exists($controller, $methodName)) {
throw new \Exception("Method '$methodName' Not Exists In Class '$className'");
}
# Call the controller method and pass the request
$controller->{$methodName}($this->request);
}
}
/**
* Dispatch a 404 Not Found response if no route matches.
* @throws \Exception
*/
private function dispatch404(): void
{
header("HTTP/1.1 404 Not Found");
view('errors.404'); # Display the 404 error view
die();
}
/**
* Dispatch a 405 Method Not Allowed response if the method is invalid.
* @throws \Exception
*/
private function dispatch405(): void
{
header("HTTP/1.1 405 Method Not Allowed");
view('errors.405'); # Display the 405 error view
die();
}
/**
* Run the router to handle the request and route matching.
* @throws \Exception
*/
public function run(): void
{
# Check for invalid requests (URI exists but method is invalid)
if ($this->invalidRequest($this->request) && !$this->currentRoute) {
$this->dispatch405(); # Dispatch 405 if method does not match
die();
}
# If no route is matched, dispatch 404
if (is_null($this->currentRoute)) {
$this->dispatch404(); # Dispatch 404 if route is not found
}
# Dispatch the matched route
$this->dispatch();
}
}
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