Router/SegmentRouter.php

<?php

class SegmentRouter implements Router
{
	public array $routes = [];

	public function add(string $method, string $route, callable $handler): Router
	{
		// Expand the route into segments and make dynamic segments into a common placeholder
		$segments = array_map(function($segment) {
			return str_starts_with($segment, ':') ? ':x' : $segment;
		}, explode('/', trim($route, '/')));

		// Push each segment into the routes array as a node, except if this is the root node
		$node = &$this->routes;
		foreach ($segments as $segment) {
			if ($segment === '') continue;
			$node = &$node[$segment];
		}

		// Add the handler to the last node
		$node[$method] = $handler;

		return $this;
	}

	public function lookup(string $method, string $uri): int|array
	{
		$node = $this->routes;

		if (isset($node[$uri])) {
			if (isset($node[$uri][$method])) return [$node[$uri][$method], []];
			return 405;
		}

		$uriSegments = explode('/', trim($uri, '/'));
		$params = [];

		foreach ($uriSegments as $segment) {
			if (isset($node[$segment])) {
				$node = $node[$segment];
				continue;
			}

			if (isset($node[':x'])) {
				$params[] = $segment;
				$node = $node[':x'];
				continue;
			}

			return 404;
		}

		if (!isset($node[$method])) return 405;

		return [$node[$method], $params];
	}


	public function clear(): Router
	{
		$this->routes = [];
		return $this;
	}
}