<?php
class Router {

    public $routes = array();

    private $types = [
        'number' => '(\d+)',
        'text' => '([a-zA-Z]+)',
        'mixed' => '(\w+)'
    ];

    public function __construct(array $routes = []) {
        $this->register($routes);
    }

    private function routeToRegExp($path) {
        $arrPath = explode('/', $path);
        $params = array( 'originalPath' );


        $arrExp = array();

        foreach ($arrPath as $segment) {

            if (strpos($segment, ':') === false) {
                $arrExp[] = $segment;
            } else {
                $expression = explode(':', $segment);
                $paramName = $expression[0];
                $params[] = $paramName;
                $arrExp[] = isset($this->types[$expression[1]]) ? $this->types[$expression[1]] : $this->types['mixed'];
            }
        }


        if($arrExp[count($arrExp) -1] == '') {
            unset($arrExp[count($arrExp) -1]);
        }

        $regString = '/' . implode('\/', $arrExp).'.*/';

        return array(
            'reg' => $regString,
            'params' => $params
        );
    }

    private function register($routes) {
        foreach ($routes as $path => $fn) {
            $pathReg = $this->routeToRegExp($path);
            $this->routes[$pathReg['reg']] = array(
                'fn' => $fn,
                'params' => $pathReg['params']
            );
        }
    }

    private function mapParams($params, $result) {
        $map = array();
        foreach($result as $key => $value) {
            $map[$params[$key]] = $value;
        }

        return $map;
    }

    public function route(array $path) {
        $selectedFn = null;
        $url = $this->normalizePath($path);
        foreach ($this->routes as $reg => $data) {
            $isMatch = preg_match($reg, $url, $match);
            if ($isMatch) {
                $selectedFn = $data['fn'];
                break;
            }
        }

        if($selectedFn == null) {
            return false;
        }
        return $selectedFn($this->mapParams($data['params'],$match));
    }

    public function add($path, $fn) {
        $pathReg = $this->routeToRegExp($path);
        $this->routes[$pathReg['reg']] = array(
            'fn' => $fn,
            'params' => $pathReg['params']
        );
    }

    private function normalizePath(array $path): string {
        $url = array();
        foreach($path as $key => $item) {
            if(is_numeric($key)) {
                $url[$key] = $item;
            }
        }

        return '/'.implode('/', $url);
    }
}