<?php
/**
 * @file src/Module/Login.php
 */
namespace Friendica\Module;

use Exception;
use Friendica\BaseModule;
use Friendica\Core\Addon;
use Friendica\Core\Authentication;
use Friendica\Core\Config;
use Friendica\Core\L10n;
use Friendica\Core\Logger;
use Friendica\Core\Renderer;
use Friendica\Core\System;
use Friendica\Database\DBA;
use Friendica\Model\User;
use Friendica\Util\DateTimeFormat;
use Friendica\Util\Network;
use LightOpenID;

require_once 'boot.php';
require_once 'include/text.php';

/**
 * Login module
 *
 * @author Hypolite Petovan <hypolite@mrpetovan.com>
 */
class Login extends BaseModule
{
	public static function content()
	{
		$a = self::getApp();

		if (x($_SESSION, 'theme')) {
			unset($_SESSION['theme']);
		}

		if (x($_SESSION, 'mobile-theme')) {
			unset($_SESSION['mobile-theme']);
		}

		if (local_user()) {
			$a->internalRedirect();
		}

		return self::form($_SESSION['return_path'], intval(Config::get('config', 'register_policy')) !== REGISTER_CLOSED);
	}

	public static function post()
	{
		$return_path = $_SESSION['return_path'];
		session_unset();
		$_SESSION['return_path'] = $return_path;
		
		// OpenId Login
		if (
			empty($_POST['password'])
			&& (
				!empty($_POST['openid_url'])
				|| !empty($_POST['username'])
			)
		) {
			$openid_url = trim(defaults($_POST, 'openid_url', $_POST['username']));

			self::openIdAuthentication($openid_url, !empty($_POST['remember']));
		}

		if (x($_POST, 'auth-params') && $_POST['auth-params'] === 'login') {
			self::passwordAuthentication(
				trim($_POST['username']),
				trim($_POST['password']),
				!empty($_POST['remember'])
			);
		}
	}

	/**
	 * Attempts to authenticate using OpenId
	 *
	 * @param string $openid_url OpenID URL string
	 * @param bool   $remember   Whether to set the session remember flag
	 */
	private static function openIdAuthentication($openid_url, $remember)
	{
		$noid = Config::get('system', 'no_openid');

		$a = self::getApp();

		// if it's an email address or doesn't resolve to a URL, fail.
		if ($noid || strpos($openid_url, '@') || !Network::isUrlValid($openid_url)) {
			notice(L10n::t('Login failed.') . EOL);
			$a->internalRedirect();
			// NOTREACHED
		}

		// Otherwise it's probably an openid.
		try {
			$openid = new LightOpenID($a->getHostName());
			$openid->identity = $openid_url;
			$_SESSION['openid'] = $openid_url;
			$_SESSION['remember'] = $remember;
			$openid->returnUrl = $a->getBaseURL(true) . '/openid';
			System::externalRedirect($openid->authUrl());
		} catch (Exception $e) {
			notice(L10n::t('We encountered a problem while logging in with the OpenID you provided. Please check the correct spelling of the ID.') . '<br /><br >' . L10n::t('The error message was:') . ' ' . $e->getMessage());
		}
	}

	/**
	 * Attempts to authenticate using login/password
	 *
	 * @param string $username User name
	 * @param string $password Clear password
	 * @param bool   $remember Whether to set the session remember flag
	 */
	private static function passwordAuthentication($username, $password, $remember)
	{
		$record = null;

		$addon_auth = [
			'username' => $username,
			'password' => $password,
			'authenticated' => 0,
			'user_record' => null
		];

		$a = self::getApp();

		/*
		 * An addon indicates successful login by setting 'authenticated' to non-zero value and returning a user record
		 * Addons should never set 'authenticated' except to indicate success - as hooks may be chained
		 * and later addons should not interfere with an earlier one that succeeded.
		 */
		Addon::callHooks('authenticate', $addon_auth);

		try {
			if ($addon_auth['authenticated']) {
				$record = $addon_auth['user_record'];

				if (empty($record)) {
					throw new Exception(L10n::t('Login failed.'));
				}
			} else {
				$record = DBA::selectFirst('user', [],
					['uid' => User::getIdFromPasswordAuthentication($username, $password)]
				);
			}
		} catch (Exception $e) {
			Logger::log('authenticate: failed login attempt: ' . notags($username) . ' from IP ' . $_SERVER['REMOTE_ADDR']);
			info('Login failed. Please check your credentials.' . EOL);
			$a->internalRedirect();
		}

		if (!$remember) {
			Authentication::setCookie(0); // 0 means delete on browser exit
		}

		// if we haven't failed up this point, log them in.
		$_SESSION['remember'] = $remember;
		$_SESSION['last_login_date'] = DateTimeFormat::utcNow();
		Authentication::setAuthenticatedSessionForUser($record, true, true);

		if (x($_SESSION, 'return_path')) {
			$return_path = $_SESSION['return_path'];
			unset($_SESSION['return_path']);
		} else {
			$return_path = '';
		}

		$a->internalRedirect($return_path);
	}

	/**
	 * @brief Tries to auth the user from the cookie or session
	 *
	 * @todo Should be moved to Friendica\Core\Session when it's created
	 */
	public static function sessionAuth()
	{
		$a = self::getApp();

		// When the "Friendica" cookie is set, take the value to authenticate and renew the cookie.
		if (isset($_COOKIE["Friendica"])) {
			$data = json_decode($_COOKIE["Friendica"]);
			if (isset($data->uid)) {

				$user = DBA::selectFirst('user', [],
					[
						'uid'             => $data->uid,
						'blocked'         => false,
						'account_expired' => false,
						'account_removed' => false,
						'verified'        => true,
					]
				);
				if (DBA::isResult($user)) {
					if ($data->hash != Authentication::getCookieHashForUser($user)) {
						Logger::log("Hash for user " . $data->uid . " doesn't fit.");
						Authentication::deleteSession();
						$a->internalRedirect();
					}

					// Renew the cookie
					// Expires after 7 days by default,
					// can be set via system.auth_cookie_lifetime
					$authcookiedays = Config::get('system', 'auth_cookie_lifetime', 7);
					Authentication::setCookie($authcookiedays * 24 * 60 * 60, $user);

					// Do the authentification if not done by now
					if (!isset($_SESSION) || !isset($_SESSION['authenticated'])) {
						Authentication::setAuthenticatedSessionForUser($user);

						if (Config::get('system', 'paranoia')) {
							$_SESSION['addr'] = $data->ip;
						}
					}
				}
			}
		}

		if (isset($_SESSION) && x($_SESSION, 'authenticated')) {
			if (x($_SESSION, 'visitor_id') && !x($_SESSION, 'uid')) {
				$contact = DBA::selectFirst('contact', [], ['id' => $_SESSION['visitor_id']]);
				if (DBA::isResult($contact)) {
					self::getApp()->contact = $contact;
				}
			}

			if (x($_SESSION, 'uid')) {
				// already logged in user returning
				$check = Config::get('system', 'paranoia');
				// extra paranoia - if the IP changed, log them out
				if ($check && ($_SESSION['addr'] != $_SERVER['REMOTE_ADDR'])) {
					Logger::log('Session address changed. Paranoid setting in effect, blocking session. ' .
						$_SESSION['addr'] . ' != ' . $_SERVER['REMOTE_ADDR']);
					Authentication::deleteSession();
					$a->internalRedirect();
				}

				$user = DBA::selectFirst('user', [],
					[
						'uid'             => $_SESSION['uid'],
						'blocked'         => false,
						'account_expired' => false,
						'account_removed' => false,
						'verified'        => true,
					]
				);
				if (!DBA::isResult($user)) {
					Authentication::deleteSession();
					$a->internalRedirect();
				}

				// Make sure to refresh the last login time for the user if the user
				// stays logged in for a long time, e.g. with "Remember Me"
				$login_refresh = false;
				if (empty($_SESSION['last_login_date'])) {
					$_SESSION['last_login_date'] = DateTimeFormat::utcNow();
				}
				if (strcmp(DateTimeFormat::utc('now - 12 hours'), $_SESSION['last_login_date']) > 0) {
					$_SESSION['last_login_date'] = DateTimeFormat::utcNow();
					$login_refresh = true;
				}
				Authentication::setAuthenticatedSessionForUser($user, false, false, $login_refresh);
			}
		}
	}

	/**
	 * @brief Wrapper for adding a login box.
	 *
	 * @param string $return_path The path relative to the base the user should be sent
	 *							 back to after login completes
	 * @param bool $register If $register == true provide a registration link.
	 *						 This will most always depend on the value of config.register_policy.
	 * @param array $hiddens  optional
	 *
	 * @return string Returns the complete html for inserting into the page
	 *
	 * @hooks 'login_hook' string $o
	 */
	public static function form($return_path = null, $register = false, $hiddens = [])
	{
		$a = self::getApp();
		$o = '';
		$reg = false;
		if ($register) {
			$reg = [
				'title' => L10n::t('Create a New Account'),
				'desc' => L10n::t('Register')
			];
		}

		$noid = Config::get('system', 'no_openid');

		if (is_null($return_path)) {
			$return_path = $a->query_string;
		}

		if (local_user()) {
			$tpl = get_markup_template('logout.tpl');
		} else {
			$a->page['htmlhead'] .= Renderer::replaceMacros(
				get_markup_template('login_head.tpl'),
				[
					'$baseurl' => $a->getBaseURL(true)
				]
			);

			$tpl = get_markup_template('login.tpl');
			$_SESSION['return_path'] = $return_path;
		}

		$o .= Renderer::replaceMacros(
			$tpl,
			[
				'$dest_url'     => self::getApp()->getBaseURL(true) . '/login',
				'$logout'       => L10n::t('Logout'),
				'$login'        => L10n::t('Login'),

				'$lname'        => ['username', L10n::t('Nickname or Email: ') , '', ''],
				'$lpassword'    => ['password', L10n::t('Password: '), '', ''],
				'$lremember'    => ['remember', L10n::t('Remember me'), 0,  ''],

				'$openid'       => !$noid,
				'$lopenid'      => ['openid_url', L10n::t('Or login using OpenID: '),'',''],

				'$hiddens'      => $hiddens,

				'$register'     => $reg,

				'$lostpass'     => L10n::t('Forgot your password?'),
				'$lostlink'     => L10n::t('Password Reset'),

				'$tostitle'     => L10n::t('Website Terms of Service'),
				'$toslink'      => L10n::t('terms of service'),

				'$privacytitle' => L10n::t('Website Privacy Policy'),
				'$privacylink'  => L10n::t('privacy policy'),
			]
		);

		Addon::callHooks('login_hook', $o);

		return $o;
	}
}