<?php

namespace TwoFAS\TwoFAS\Storage;

use DateTime;
use TwoFAS\Api\Authentication;
use TwoFAS\Api\AuthenticationCollection;
use TwoFAS\TwoFAS\Exceptions\User_Not_Found_Exception;

class Authentication_Storage {

	const USER_AUTHENTICATION_STATUS_OPEN = 'OPEN';
	const USER_AUTHENTICATION_STATUS_NONE = 'NONE';
	const AUTHENTICATION_METHOD           = 'twofas_authentication_method';
	const AUTHENTICATION_VALID_UNTIL      = 'twofas_authentication_valid_until';
	const AUTHENTICATION_STATUS           = 'twofas_is_authentication_open';
	const AUTHENTICATION_ID               = 'twofas_authentication_id';

	/**
	 * @var User_Storage
	 */
	private $user_storage;

	/**
	 * @param User_Storage $user_storage
	 */
	public function __construct( User_Storage $user_storage ) {
		$this->user_storage = $user_storage;
	}

	/**
	 * @return int
	 *
	 * @throws User_Not_Found_Exception
	 */
	public function get_authentication_valid_until() {
		return (int) $this->user_storage->get_user_meta( self::AUTHENTICATION_VALID_UNTIL );
	}

	/**
	 * @return bool
	 *
	 * @throws User_Not_Found_Exception
	 */
	public function is_authentication_expired() {
		$valid_until = $this->get_authentication_valid_until();

		return $valid_until < time();
	}

	/**
	 * @return AuthenticationCollection
	 *
	 * @throws User_Not_Found_Exception
	 */
	public function get_authentications() {
		return $this->create_collection( $this->get_authentications_as_array() );
	}

	/**
	 * @return array
	 *
	 * @throws User_Not_Found_Exception
	 */
	public function get_authentications_as_array() {
		$authentications = $this->get_authentication_id();

		if ( ! is_array( $authentications ) ) {
			$authentications = array();
		}

		return $authentications;
	}

	/**
	 * @return bool
	 *
	 * @throws User_Not_Found_Exception
	 */
	public function has_open_authentication() {
		return $this->user_storage->get_user_meta( self::AUTHENTICATION_STATUS ) === self::USER_AUTHENTICATION_STATUS_OPEN;
	}

	/**
	 * @param Authentication $authentication
	 *
	 * @throws User_Not_Found_Exception
	 */
	public function open_authentication( Authentication $authentication ) {
		$this->user_storage->set_user_meta( self::AUTHENTICATION_STATUS, self::USER_AUTHENTICATION_STATUS_OPEN );
		$authentications   = $this->get_authentications_as_array();
		$authentications[] = $authentication->id();
		$this->set_authentication_id( $authentications );
		$timestamp = $authentication->validTo()->getTimestamp();
		$this->save_authentication_valid_until( $timestamp );
	}

	/**
	 * @throws User_Not_Found_Exception
	 */
	public function close_authentication() {
		$this->reset_authentication();
		$this->set_authentication_id( array() );
	}

	/**
	 * @return array|null|string
	 *
	 * @throws User_Not_Found_Exception
	 */
	private function get_authentication_id() {
		return $this->user_storage->get_user_meta( self::AUTHENTICATION_ID );
	}

	/**
	 * @param array $authentications
	 *
	 * @return AuthenticationCollection
	 */
	private function create_collection( array $authentications ) {
		$collection = new AuthenticationCollection();

		array_map( function ( $id ) use ( $collection ) {
			$auth = new Authentication( $id, new DateTime(), new DateTime() );
			$collection->add( $auth );
		}, $authentications );

		return $collection;
	}

	/**
	 * @param array|string $authentication_id
	 *
	 * @throws User_Not_Found_Exception
	 */
	private function set_authentication_id( $authentication_id ) {
		$this->user_storage->set_user_meta( self::AUTHENTICATION_ID, $authentication_id );
	}

	/**
	 * @param int $timestamp
	 *
	 * @throws User_Not_Found_Exception
	 */
	private function save_authentication_valid_until( $timestamp ) {
		$this->user_storage->set_user_meta( self::AUTHENTICATION_VALID_UNTIL, $timestamp );
	}

	/**
	 * @throws User_Not_Found_Exception
	 */
	private function reset_authentication() {
		$this->user_storage->set_user_meta( self::AUTHENTICATION_STATUS, self::USER_AUTHENTICATION_STATUS_NONE );
	}
}