<?php

namespace MyApp\Core;

use ReflectionMethod;
use ReflectionClass;
use ReflectionException;

/**
 * Class Router.
 */
class Router
{
    /**
     * @var array
     */
    private $routes = [];

    public function __construct()
    {
        $this->getRoutesFromControllers();
        $this->addRoute('/^.*$/', 'MyApp\\Controller\\ErrorsController',
            'get404', ['GET']);
        $this->addRoute('/^.*$/', 'MyApp\\Controller\\ErrorsController',
            'post404', ['POST', 'PUT', 'DELETE']);

        $this->run();
    }

    /**
     * Get Routes from a comment on method in Controllers.
     */
    private function getRoutesFromControllers()
    {
        /* @var \App $app */
        global $app;

        /* @var Config $config */
        $config = $app->config;

        $controllersDir = $config->getControllersDir();
        $controllersNamespace = $config->getControllersNamespace();

        $files = scandir($controllersDir);
        foreach ($files as $file) {
            $className = strstr($file, '.php', true);
            $fileName = $controllersDir.$file;
            if (is_file($fileName) && false !== $className) {
                try {
                    $refClass = new ReflectionClass($controllersNamespace.$className);
                    $methods = $refClass->getMethods(ReflectionMethod::IS_PUBLIC);
                    foreach ($methods as $method) {
                        $tags = $app->parseTagsFromComment($method->getDocComment());
                        if (is_array($tags)) {
                            if (array_key_exists('RouteRegExp', $tags)) {
                                if (!array_key_exists('HttpMethod', $tags)) {
                                    $tags['HttpMethod'] = ['GET'];
                                }

                                $this->addRoute($tags['RouteRegExp'],
                                    $method->class, $method->name,
                                    $tags['HttpMethod']);
                            }
                        }
                    }
                } catch (ReflectionException $e) {
                    var_dump($e);
                }
            }
        }
    }

    /**
     * Add route to array.
     *
     * @param string $regExp
     * @param string $className
     * @param string $classMethod
     * @param array  $httpMethods
     */
    private function addRoute(
        string $regExp,
        string $className,
        string $classMethod,
        array $httpMethods
    ) {
        foreach ($httpMethods as $httpMethod) {
            $this->routes[strtoupper($httpMethod)][] = [
                $regExp,
                $className,
                $classMethod,
            ];
        }
    }

    /**
     * Run parse request.
     */
    private function run()
    {
        if (array_key_exists($_SERVER['REQUEST_METHOD'], $this->routes)) {
            foreach ($this->routes[$_SERVER['REQUEST_METHOD']] as $route_array) {
                if (preg_match($route_array[0], $_SERVER['REQUEST_URI'],
                    $matches)) {
                    $obj = new $route_array[1]();
                    $param_arr = [];
                    foreach ($matches as $key => $value) {
                        if (!is_int($key)) {
                            $param_arr[] = $value;
                        }
                    }
                    call_user_func_array([$obj, $route_array[2]], $param_arr);
                    break;
                }
            }
        }
    }
}