1 files changed, 220 insertions, 0 deletions
diff --git a/src/Routing/Router.php b/src/Routing/Router.php
new file mode 100644
index 0000000..4c2d615
--- /dev/null
+++ b/src/Routing/Router.php
@@ -0,0 +1,220 @@
+<?php
+
+declare(strict_types=1);
+
+namespace BrettParson\MiniRoute\Routing;
+
+use BrettParson\MiniRoute\Controller\ControllerResolverInterface;
+use BrettParson\MiniRoute\Http\RequestInterface;
+use BrettParson\MiniRoute\Http\ResponseInterface;
+use BrettParson\MiniRoute\Middleware\MiddlewareInterface;
+use BrettParson\MiniRoute\Middleware\MiddlewarePipeline;
+use LogicException;
+
+final class Router
+{
+    private RouteLoader $loader;
+
+    private RouteMatcher $matcher;
+
+    /** @var list<RouteDef> */
+    private array $routes = [];
+
+    /** @var list<array{prefix: string, middleware: list<string>, methods: list<string>|null}> */
+    private array $groups = [];
+
+    /** @var callable(RequestInterface): ResponseInterface|null */
+    private $notFoundHandler = null;
+
+    public function __construct(
+        private readonly ControllerResolverInterface $resolver,
+        ?RouteLoader $loader = null,
+        ?RouteMatcher $matcher = null,
+    ) {
+        $this->loader = $loader ?? new RouteLoader();
+        $this->matcher = $matcher ?? new RouteMatcher();
+    }
+
+    /**
+     * Register every route declared on a controller class.
+     *
+     * @param class-string $controllerClass
+     */
+    public function registerController(string $controllerClass): void
+    {
+        foreach ($this->loader->load($controllerClass) as $route) {
+            $this->add($route);
+        }
+    }
+
+    /**
+     * @param list<class-string> $controllerClasses
+     */
+    public function registerControllers(array $controllerClasses): void
+    {
+        foreach ($controllerClasses as $controllerClass) {
+            $this->registerController($controllerClass);
+        }
+    }
+
+    /**
+     * Apply middleware to every route under a path prefix.
+     *
+     * @param list<string> $middleware Middleware class names, outermost first.
+     * @param list<string>|null $methods Restrict to these HTTP methods, or null for all.
+     */
+    public function group(string $prefix, array $middleware, ?array $methods = null): void
+    {
+        $this->groups[] = [
+            'prefix' => $this->normalizePrefix($prefix),
+            'middleware' => $middleware,
+            'methods' => $methods === null ? null : array_map('strtoupper', $methods),
+        ];
+    }
+
+    /**
+     * Set the handler used when no route matches. Defaults to throwing
+     * RouteNotFoundException when unset.
+     *
+     * @param callable(RequestInterface): ResponseInterface $handler
+     */
+    public function setNotFoundHandler(callable $handler): void
+    {
+        $this->notFoundHandler = $handler;
+    }
+
+    public function dispatch(RequestInterface $request): ResponseInterface
+    {
+        $method = strtoupper($request->method());
+        $path = $this->normalizePath($request->path());
+
+        $route = $this->find($method, $path);
+
+        if ($route === null) {
+            if ($this->notFoundHandler !== null) {
+                return ($this->notFoundHandler)($request);
+            }
+
+            throw new RouteNotFoundException("No route matches {$method} {$path}");
+        }
+
+        $params = $this->matcher->extractParams($route, $path);
+
+        if ($params !== []) {
+            $request = $request->withParams($params);
+        }
+
+        $controller = $this->resolver->resolve($route->controllerClass);
+
+        $core = static fn (RequestInterface $r): ResponseInterface => $controller->{$route->controllerMethod}($r);
+
+        $middleware = array_merge(
+            $this->groupMiddleware($route, $method),
+            $route->middleware,
+        );
+
+        return MiddlewarePipeline::compose($this->resolveMiddleware($middleware), $core)($request);
+    }
+
+    private function add(RouteDef $route): void
+    {
+        foreach ($this->routes as $existing) {
+            if ($existing->method === $route->method && $existing->path === $route->path) {
+                throw new RouteRegistrationException(
+                    "Duplicate route {$route->method} {$route->path} declared on "
+                    . "{$existing->controllerClass}::{$existing->controllerMethod} and "
+                    . "{$route->controllerClass}::{$route->controllerMethod}",
+                );
+            }
+        }
+
+        $this->routes[] = $route;
+
+        usort($this->routes, fn (RouteDef $a, RouteDef $b): int => $this->matcher->compare($a, $b));
+    }
+
+    private function find(string $method, string $path): ?RouteDef
+    {
+        foreach ($this->routes as $route) {
+            if ($this->matcher->matches($route, $method, $path)) {
+                return $route;
+            }
+        }
+
+        return null;
+    }
+
+    /**
+     * @return list<string>
+     */
+    private function groupMiddleware(RouteDef $route, string $method): array
+    {
+        $middleware = [];
+
+        foreach ($this->groups as $group) {
+            if (!$this->matchesPrefix($group['prefix'], $route->path)) {
+                continue;
+            }
+
+            if ($group['methods'] !== null && !in_array($method, $group['methods'], true)) {
+                continue;
+            }
+
+            $middleware = array_merge($middleware, $group['middleware']);
+        }
+
+        return $middleware;
+    }
+
+    /**
+     * @param list<string> $classes
+     * @return list<MiddlewareInterface>
+     */
+    private function resolveMiddleware(array $classes): array
+    {
+        $instances = [];
+
+        foreach ($classes as $class) {
+            $instance = $this->resolver->resolve($class);
+
+            if (!$instance instanceof MiddlewareInterface) {
+                throw new LogicException("Middleware {$class} must implement " . MiddlewareInterface::class);
+            }
+
+            $instances[] = $instance;
+        }
+
+        return $instances;
+    }
+
+    private function matchesPrefix(string $prefix, string $path): bool
+    {
+        if ($prefix === '') {
+            return true;
+        }
+
+        if ($path === $prefix) {
+            return true;
+        }
+
+        return str_starts_with($path, $prefix . '/');
+    }
+
+    private function normalizePrefix(string $prefix): string
+    {
+        $trimmed = rtrim($prefix, '/');
+
+        return $trimmed === '' ? '' : '/' . ltrim($trimmed, '/');
+    }
+
+    private function normalizePath(string $path): string
+    {
+        $parsed = parse_url($path, PHP_URL_PATH);
+
+        if (!is_string($parsed) || $parsed === '') {
+            return '/';
+        }
+
+        return '/' . trim($parsed, '/');
+    }
+}