<?php
namespace Pecee\Http\Middleware;

use Pecee\CsrfToken;
use Pecee\Exceptions\TokenMismatchException;
use Pecee\Http\Request;
use Pecee\SimpleRouter\Route\ILoadableRoute;

class BaseCsrfVerifier implements IMiddleware
{
	const POST_KEY = 'csrf-token';
	const HEADER_KEY = 'X-CSRF-TOKEN';

	protected $except;
	protected $csrfToken;
	protected $token;

	public function __construct()
	{
		$this->csrfToken = new CsrfToken();

		// Generate or get the CSRF-Token from Cookie.
		$this->token = (!$this->hasToken()) ? $this->generateToken() : $this->csrfToken->getToken();
	}

	/**
	 * Check if the url matches the urls in the except property
	 * @param Request $request
	 * @return bool
	 */
	protected function skip(Request $request)
	{
		if ($this->except === null || is_array($this->except) === false) {
			return false;
		}

		foreach ($this->except as $url) {
			$url = rtrim($url, '/');
			if ($url[strlen($url) - 1] === '*') {
				$url = rtrim($url, '*');
				$skip = (stripos($request->getUri(), $url) === 0);
			} else {
				$skip = ($url === rtrim($request->getUri(), '/'));
			}

			if ($skip) {
				return true;
			}
		}

		return false;
	}

	public function handle(Request $request, ILoadableRoute &$route = null)
	{

		if ($request->getMethod() !== 'get' && !$this->skip($request)) {

			$token = $request->getInput()->post->get(static::POST_KEY);

			// If the token is not posted, check headers for valid x-csrf-token
			if ($token === null) {
				$token = $request->getHeader(static::HEADER_KEY);
			}

			if (!$this->csrfToken->validate($token)) {
				throw new TokenMismatchException('Invalid csrf-token.');
			}

		}

	}

	public function generateToken()
	{
		$token = $this->csrfToken->generateToken();
		$this->csrfToken->setToken($token);
		return $token;
	}

	public function hasToken()
	{
		if ($this->token != null) {
			return true;
		}

		return $this->csrfToken->hasToken();
	}

	public function getToken()
	{
		return $this->token;
	}

}