index/src/Routing/Router.php

<?php
// Router.php
// Created: 2022-01-18
// Updated: 2022-02-27

namespace Index\Routing;

use InvalidArgumentException;

/**
 * Provides an application router.
 */
class Router {
    private RouteInfo $route;

    /**
     * Constructs a Router object.
     */
    public function __construct() {
        $this->route = new RouteInfo;
    }

    /**
     * Resolves a request method and uri.
     *
     * @param string $method Request method.
     * @param string $path Request path.
     * @param array $args Arguments to be passed on to the callables.
     * @return RouteCallable A collection of callables representing the route.
     */
    public function resolve(string $method, string $path, array $args = []): RouteCallable {
        $method = strtolower($method);
        if($method === 'head')
            $method = 'get';

        return $this->route->resolve($method, trim($path, '/'), $args);
    }

    /**
     * Apply middleware functions to a path.
     *
     * @param string $path Path to apply the middleware to.
     * @param callable $handler Middleware function.
     */
    public function use(string $path, callable $handler): void {
        $this->route->addMiddleware(trim($path, '/'), $handler);
    }

    /**
     * Merges another router with this one with possibility of changing its root.
     *
     * @param string $path Base path to use.
     * @param Router $router Router object to inherit from.
     */
    public function merge(string $path, Router $router): void {
        $this->route->mergeRoute(trim($path, '/'), $router->route);
    }

    /**
     * Adds a new route.
     *
     * @param string $method Request method.
     * @param string $path Request path.
     * @param callable $handler Request handler.
     */
    public function add(string $method, string $path, callable $handler): void {
        if(empty($method))
            throw new InvalidArgumentException('$method may not be empty.');

        $this->route->addMethod($method, trim($path, '/'), $handler);
    }

    /**
     * Adds a new GET route.
     *
     * @param string $path Request path.
     * @param callable $handler Request handler.
     */
    public function get(string $path, callable $handler): void {
        $this->add('get', $path, $handler);
    }

    /**
     * Adds a new POST route.
     *
     * @param string $path Request path.
     * @param callable $handler Request handler.
     */
    public function post(string $path, callable $handler): void {
        $this->add('post', $path, $handler);
    }

    /**
     * Adds a new DELETE route.
     *
     * @param string $path Request path.
     * @param callable $handler Request handler.
     */
    public function delete(string $path, callable $handler): void {
        $this->add('delete', $path, $handler);
    }

    /**
     * Adds a new PATCH route.
     *
     * @param string $path Request path.
     * @param callable $handler Request handler.
     */
    public function patch(string $path, callable $handler): void {
        $this->add('patch', $path, $handler);
    }

    /**
     * Adds a new PUT route.
     *
     * @param string $path Request path.
     * @param callable $handler Request handler.
     */
    public function put(string $path, callable $handler): void {
        $this->add('put', $path, $handler);
    }

    /**
     * Adds a new OPTIONS route.
     *
     * @param string $path Request path.
     * @param callable $handler Request handler.
     */
    public function options(string $path, callable $handler): void {
        $this->add('options', $path, $handler);
    }
}