<?php

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

	public function add(string $method, string $route, callable $handler): Router
	{
		// Expand the route into segments
		$segments = explode('/', trim($route, '/'));

		// Push each segment into the routes array as a node
		$node = &$this->routes;
		foreach ($segments as $segment) $node = &$node[$segment];

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

		return $this;
	}

	public function lookup(string $method, string $uri): int|array
	{
		// Expand the URI into segments
		$uriSegments = explode('/', trim($uri, '/'));
		$node = $this->routes;
		$params = [];

		// Traverse the routes array to find the handler
		foreach ($uriSegments as $segment) {
			// Check if the segment exists in the node, or if there's a dynamic segment
			if (!isset($node[$segment])) {
				$dynamicSegment = $this->matchDynamicSegment($node, $segment);
				if ($dynamicSegment) {
					$params[] = $segment;
					$node = $node[$dynamicSegment];
				} else {
					return 404;
				}
			} else {
				$node = $node[$segment];
			}
		}

		// If the HTTP method is not supported, return 405
		if (!isset($node[$method])) return 405;

		// Return the handler
		return [$node[$method], $params];
	}

	// Look through a node to find a dynamic segment
	private function matchDynamicSegment(array $node, string $segment): string|false
	{
		foreach (array_keys($node) as $key) {
			// If the key starts with a :, it's a dynamic segment
			if (strpos($key, ':') === 0) return $key;
		}

		return false;
	}

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