<?php namespace SocialNorm;

use SocialNorm\Exceptions\InvalidAuthorizationCodeException;

class SocialNorm
{
	protected $providers;
	protected $session;
	protected $request;
	protected $stateGenerator;

	public function __construct(
		ProviderRegistry $providers,
		Session $session,
		Request $request,
		StateGenerator $stateGenerator
	)
	{
		$this->providers = $providers;
		$this->session = $session;
		$this->request = $request;
		$this->stateGenerator = $stateGenerator;
	}

	public function registerProvider($alias, Provider $provider)
	{
		$this->providers->registerProvider($alias, $provider);
	}

	public function authorize($providerAlias)
	{
		$state = $this->stateGenerator->generate();

		// this is for some reason needed, plain put doesn't work across the redirect
		\Session::put('oauth.state', $state);
		\Session::save();

		return $this->getProvider($providerAlias)->authorizeUrl($state);
	}

	public function getUser($providerAlias)
	{
		$this->verifyState();
		return $this->getProvider($providerAlias)->getUser();
	}

	protected function getProvider($providerAlias)
	{
		return $this->providers->getProvider($providerAlias);
	}

	protected function verifyState()
	{
        if (\Session::get('oauth.state') !== $this->request->state()) {
            throw new InvalidAuthorizationCodeException;
        }
	}
}