NPSR - PSRs? We don't need to stinkin' PSRs.

.htaccess

RewriteEngine On

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ index.php?_uri=$1 [L]

index.php

<?php
define('FRONT_CONTROLLER', true);
include 'npsr.php';

get('/', function ($params) {
    echo 'Hello World!';
});

go();

npsr.php

<?php if ( ! defined('FRONT_CONTROLLER')) die('No No No');

class NpsrNotFoundException extends Exception { }

class Npsr
{
    private $routes = array(
        'GET' => array(),
        'POST' => array(),
        'PUT' => array(),
        'DELETE' => array(),
        'OPTIONS' => array(),
    );

    public function get($uri, $callback) {
        $this->addRoute('GET', $uri, $callback);
    }

    public function post($uri, $callback) {
        $this->addRoute('POST', $uri, $callback);
    }

    public function put($uri, $callback) {
        $this->addRoute('PUT', $uri, $callback);
    }

    public function delete($uri, $callback) {
        $this->addRoute('DELETE', $uri, $callback);
    }

    public function options($uri, $callback) {
        $this->addRoute('OPTIONS', $uri, $callback);
    }

    public function go() {
        $uri = $params['_uri'];
        $method = $this->getMethod();
        $params = $this->getParams();
        if (array_key_exists('_uri', $params)) {
            $uri = $params['_uri'];
            unset($params['_uri']);
        } else {
            $uri = '/';
        }
        $route = null;
        foreach ($this->routes[$method] as $r) {
            if (preg_match('/'.preg_quote($r['uri'], '/').'/', $uri)) {
                $route = $r;
                break;
            }
        }

        if ($route === null) {
            throw new NpsrNotFoundException("No route for {$uri}");
        }
        
        $route['callback']($params);
    }

    private function addRoute($method, $uri, $callback) {
        array_push($this->routes[strtoupper($method)], array('uri' => $uri, 'callback' => $callback));
    }

    private function getParams() {
        switch ($this->getMethod()) {
            case 'GET':
                return $_GET;
            case 'POST':
                return $_POST;
            default:
                parse_str(file_get_contents("php://input"), $params);
                return $params;
        }
    }

    private function getMethod() {
        if ( ! isset($_SERVER['HTTP_METHOD'])) {
            return 'GET';
        }

        return strtoupper($_SERVER['HTTP_METHOD']);
    }
}

$npsr = new Npsr;

function get($uri, $callback) {
    global $npsr;
    $npsr->get($uri, $callback);
}

function post($uri, $callback) {
    global $npsr;
    $npsr->post($uri, $callback);
}

function put($uri, $callback) {
    global $npsr;
    $npsr->put($uri, $callback);
}

function delete($uri, $callback) {
    global $npsr;
    $npsr->delete($uri, $callback);
}

function options($uri, $callback) {
    global $npsr;
    $npsr->options($uri, $callback);
}

function go() {
    global $npsr;
    $npsr->go();
}