<?php
class Router
{
    private $request;
    private $supportedHttpMethods = array(
        "GET",
        "POST"
    );

    function __construct(IRequest $request)
    {
     $this->request = $request;
    }

    function __call($name, $args)
    {
        list($route, $method) = $args;

        if(!in_array(strtoupper($name), $this->supportedHttpMethods))
        {
            $this->invalidMethodHandler();
        }

        $this->{strtolower($name)}[$this->formatRoute($route)] = $method;
    }

    /**
     * Removes trailing forward slashes from the right of the route.
     * @param route (string)
     */
    private function formatRoute($route)
    {
        $result = rtrim($route, '/');
        if ($result === '')
        {
            return '/';
        }
        return $result;
    }

    private function invalidMethodHandler()
    {
        header("{$this->request->serverProtocol} 405 Method Not Allowed");
    }

    private function defaultRequestHandler()
    {
        header("{$this->request->serverProtocol} 404 Not Found");
    }

    /**
     * Resolves a route
     */
    function resolve()
    {
        $methodDictionary = $this->{strtolower($this->request->requestMethod)};
        $formatedRoute    = $this->formatRoute($this->request->requestUri);
        $method           = $methodDictionary[$formatedRoute];

        if(is_null($method))
        {
            $this->defaultRequestHandler();
            return;
        }

        echo call_user_func_array($method, array($this->request));
    }

    function __destruct()
    {
        $this->resolve();
    }
}

interface IRequest
{
    public function getBody();
}

class Request implements IRequest
{
    function __construct()
    {
        $this->bootstrapSelf();
    }

    private function bootstrapSelf()
    {
        foreach($_SERVER as $key => $value)
        {
            $this->{$this->toCamelCase($key)} = $value;
        }
    }

    private function toCamelCase($string)
    {
        $result = strtolower($string);

        preg_match_all('/_[a-z]/', $result, $matches);

        foreach($matches[0] as $match)
        {
                $c = str_replace('_', '', strtoupper($match));
                $result = str_replace($match, $c, $result);
        }

        return $result;
    }

    public function getBody()
    {
        if($this->requestMethod === "GET") { return; }

        if($this->requestMethod === "POST")
        {
            $body = array();
            foreach($_POST as $key => $value)
            {
                $body[$key] = filter_input(INPUT_POST, $key, FILTER_SANITIZE_SPECIAL_CHARS);
            }

            return $body;
        }
    }
}