public function getAuthorizeUri($redirect_uri, $scope = Client::SCOPE_READ) {

		$state = sha1(mt_rand());

		$_SESSION[$this->oauth_key] = [
			'redirect_uri'	=> $redirect_uri,
			'scope'			=> $scope,
			'state'			=> $state,
		];

		return $this->client->authorizationEndpoint() . '?' . http_build_query([
			'response_type'	=> 'code',
			'client_id'		=> $this->client->id(),
			'client_secret' => $this->client->secret(),
			'redirect_uri'	=> $redirect_uri,
			'scope'			=> $scope,
			'state'			=> $state,
		]);
	}