path: root/modules-available/locationinfo/inc/locationinfo.inc.php

<?php

class LocationInfo
{

	/**
	 * Gets the pc data and returns it's state.
	 *
	 * @param array $pc The pc data from the db. Array('state' => xx, 'lastseen' => xxx)
	 * @return string pc state
	 */
	public static function getPcState(array $pc): string
	{
		$lastseen = (int)$pc['lastseen'];
		$NOW = time();

		if ($pc['state'] === 'OFFLINE' && $NOW - $lastseen > 30 * 86400) {
			return "BROKEN";
		}
		return $pc['state'];
	}

	/**
	 * Return list of locationids associated with given panel.
	 *
	 * @param string $paneluuid panel
	 * @param bool $recursive if true and paneltype == SUMMARY the result is recursive with all child room ids.
	 * @return int[] locationIds
	 */
	public static function getLocationsOr404(string $paneluuid, bool $recursive = true): array
	{
		$panel = Database::queryFirst('SELECT paneltype, locationids FROM locationinfo_panel WHERE paneluuid = :paneluuid',
			compact('paneluuid'));
		if ($panel !== false) {
			$idArray = array_map('intval', explode(',', $panel['locationids']));
			if ($panel['paneltype'] == "SUMMARY" && $recursive) {
				foreach ($idArray as $lid) {
					$idArray = array_merge($idArray, Location::getAllLocationIds($lid));
				}
			}
			return $idArray;
		}
		http_response_code(404);
		die('Panel not found');
	}

	/**
	 * Set current error message of given server. Pass null or false to clear.
	 *
	 * @param int $serverId id of server
	 * @param string|array $message error message to set, array of error message struct, null or false clears error.
	 */
	public static function setServerError(int $serverId, $message): void
	{
		if (is_array($message)) {
			$fatal = false;
			foreach ($message as $m) {
				if ($m['fatal']) {
					$fatal = $m['message'];
				}
				Database::exec('INSERT INTO locationinfo_backendlog (serverid, dateline, message)
						VALUES (:sid, :dateline, :message)', [
					'sid' => $serverId,
					'dateline' => $m['time'],
					'message' => ($m['fatal'] ? '[F]' : '[W]') . $m['message'],
				]);
			}
			$message = $fatal;
		}
		if ($message === false || $message === null) {
			Database::exec("UPDATE `locationinfo_coursebackend` SET error = NULL
					WHERE serverid = :id", array('id' => $serverId));
		} else {
			if (empty($message))  {
				$message = '<empty error message>';
			}
			$error = json_encode(array(
				'timestamp' => time(),
				'error' => (string)$message
			));
			Database::exec("UPDATE `locationinfo_coursebackend` SET error = :error
					WHERE serverid = :id", array('id' => $serverId, 'error' => $error));
		}
	}

	public static function getPanelParameters(string $type): array
	{
		switch ($type) {
		case 'DEFAULT':
			$return = [
				'string' => [],
				'int' => [
					'mode' => ['section' => 'general', 'default' => 1, 'min' => 1, 'max' => 4],
					'startday' => ['section' => 'calendar', 'default' => 0, 'min' => 0, 'max' => 7],
					'daystoshow' => ['section' => 'calendar', 'default' => 7, 'min' => 1, 'max' => 7],
					'rotation' => ['section' => 'roomplan', 'default' => 0, 'min' => 0, 'max' => 3],
					'scale' => ['section' => 'styling', 'default' => 50, 'min' => 10, 'max' => 90],
					'switchtime' => ['section' => 'general', 'default' => 20, 'min' => 1, 'max' => 120],
					'calupdate' => ['section' => 'calendar', 'default' => 120, 'min' => 5, 'max' => 300],
					'roomupdate' => ['section' => 'roomplan', 'default' => 30, 'min' => 5, 'max' => 60],
				],
				'bool' => [
					'qrcode' => ['section' => 'general'],
					'vertical' => ['section' => 'styling'],
					'eco' => ['section' => 'styling'],
					'prettytime' => ['section' => 'styling'],
					'roomplanner' => ['section' => 'roomplan', 'default' => true],
					'scaledaysauto' => ['section' => 'calendar', 'default' => true],
					'hostname' => ['section' => 'roomplan', 'default' => false],
				],
			];
			break;
		case 'URL':
			$return = [
				'string' => [
					'url' => ['section' => 'general', 'default' => 'https://www.bwlehrpool.de/'],
					'blacklist' => ['section' => false],
					'whitelist' => ['section' => false, 'default' => ''],
					'browser' => ['section' => 'general', 'default' => 'firefox', 'enum' => [
						'firefox', 'slx-browser', 'chromium',
					]],
					'accept-language' => ['section' => 'general', 'default' => 'de-DE,en-US'],
					'screen-rotation' => ['section' => 'general', 'default' => '', 'enum' => [
						'', 'left', 'right', 'inverted',
					]],
					'allow-tty' => ['section' => 'general', 'enum' => [
						'', 'yes', 'no',
					]],
				],
				'int' => [
					'reload-minutes' => ['section' => 'general', 'default' => 0, 'min' => 0],
					'zoom-factor' => [
						'section' => 'browser-tweaks',
						'default' => 100,
						'min' => 10,
						'max' => 1000,
						'slider' => '%',
					],
				],
				'bool' => [
					'insecure-ssl' => [
						'section' => 'browser-tweaks',
						'class' => 'browser-specific show-slx-browser show-chromium',
					],
					'split-login' => ['section' => 'general'],
					'interactive' => [
						'section' => 'browser-tweaks',
						'class' => 'browser-specific show-firefox show-chromium',
					],
					'hw-video' => [
						'section' => 'browser-tweaks',
						'class' => 'browser-specific show-firefox show-chromium',
					],
				],
			];
			break;
		case 'UPCOMING':
			$return = [
				'string' => [
					'heading' => ['section' => 'general'],
					'subheading' => ['section' => 'general'],
					'color_bg' => ['section' => 'styling', 'default' => 'rgb(52, 73, 154)'],
					'color_fg' => ['section' => 'styling', 'default' => '#fff'],
					'color_section' => ['section' => 'styling', 'default' => 'rgba(255,255,255, .2)'],
					'color_time' => ['section' => 'styling', 'default' => 'rgba(255,255,255, .5)'],
				],
				'bool' => [
					'qrcode' => ['section' => 'general'],
				],
			];
			break;
		case 'SUMMARY':
			$return = [
				'string' => [],
				'int' => [
					'panelupdate' => ['section' => 'roomplan', 'default' => 30, 'min' => 5, 'max' => 60],
					'roomplanner' => ['section' => 'roomplan', 'default' => 0, 'enum' => [0, 1]],
				],
				'bool' => [
					'eco' => ['section' => 'styling'],
				],
			];
			break;
		default:
			ErrorHandler::traceError("Invalid panel type: '$type'");
		}
		if ($type !== 'URL') {
			$mods = [];
			$lowType = strtolower($type);
			foreach (glob('modules/locationinfo/templates/frontend-' . $lowType . '-*.html') as $file) {
				if (!preg_match('/frontend-' . $lowType . '-([a-z0-9]+)\.html$/', $file, $matches))
					continue;
				$mods[] = $matches[1];
			}
			if (!empty($mods)) {
				array_unshift($mods, '');
				$return['string']['mod'] = ['section' => 'general', 'enum' => $mods];
			}
			$return['string']['language'] = [
				'section' => 'general',
				'default' => defined('LANG') ? LANG : 'en',
				'enum' => Dictionary::getLanguages(),
			];
			$return['bool']['language-system'] = ['section' => 'general'];
		}
		return $return;
	}

	/**
	 * Takes a configuration for a specific panel type, and creates additional keys for all
	 * known boolean options that are set in the config, after the following pattern
	 * ```
	 * 'somekey' => true
	 * creates:
	 * 'somekey_checked' => 'checked'
	 * ```
	 * so that it can be used in templates more easily.
	 */
	public static function makeCheckedProperties(string $paneltype, array &$config): void
	{
		$params = self::getPanelParameters($paneltype);
		if (empty($params['bool']))
			return;
		Render::mangleFields($config, array_keys($params['bool']));
	}

	/**
	 * Read panel config from POST parameters for given panel type.
	 * @param string $type Type to process POST parameters for
	 * @return array mangled and sanitized config
	 */
	public static function panelConfigFromPost(string $type): array
	{
		$conf = [];
		Request::processPostParameters($conf, self::getPanelParameters($type));
		return $conf;
	}

	/**
	 * Creates and returns a default config for room that didn't save a config yet.
	 *
	 * @return array Return a default config.
	 */
	public static function defaultPanelConfig(string $type): array
	{
		$p = self::getPanelParameters($type);
		$out = [];
		foreach ($p as $sub) {
			foreach ($sub as $field => $options) {
				$out[$field] = $options['default'] ?? $options['min']
					?? (isset($options['enum']) ? array_shift($options['enum']) : '');
			}
		}
		return $out;
	}

	/**
	 * Get data for editing a panel based on the type and current configuration.
	 * The returned data is suitable for rendering it in a mustache template.
	 * @param string $type The type of template to edit.
	 * @param array $current The current configuration data.
	 * @return array The edit template data formatted for display in a mustache template.
	 */
	public static function getEditTemplateData(string $type, array $current): array
	{
		$params = self::getPanelParameters($type);
		// Make sure panelname is the first element
		$params['string'] = array_reverse($params['string'], true);
		$params['string']['panelname'] = [];
		$params['string'] = array_reverse($params['string'], true);
		$params['bool']['ispublic'] = ['section' => 'general'];
		$sections = [];
		foreach ($params as $varType => $options) {
			foreach ($options as $key => $properties) {
				if (isset($properties['enum']) && empty($properties['enum']))
					continue; // Enum with no values - ignore
				$section = ($properties['section'] ?? 'general');
				if ($section === false) // To be hidden
					continue;
				if (!isset($sections[$section])) {
					$sections[$section] = [];
				}
				$sections[$section][] = [
					'title' => Dictionary::translateFile('panel-params', $key, true),
					'helptext' => Dictionary::translateFile('panel-params', $key . '_helptext', true),
					'html' => self::makeEditField($varType, $key, $properties, $current[$key] ?? ''),
					'class' => $properties['class'] ?? null,
				];
			}
		}
		$output = [];
		foreach ($sections as $sectionName => $sectionData) {
			$output[] = [
				'title' => Dictionary::translateFile('panel-params', 'section_' . $sectionName, true),
				'elements' => $sectionData,
			];
		}
		return $output;
	}

	/**
	 * Transform the given variable into an edit field based on its type and configuration.
	 *
	 * @param string $varType The type of the variable ('int', 'bool', 'string').
	 * @param string $key The key used in the form field name attribute.
	 * @param array $opts The variable configuration array.
	 * @param mixed $current The current value of the variable.
	 * @return string The HTML representation of the edit field for the given variable.
	 */
	private static function makeEditField(string $varType, string $key, array $opts, $current): string
	{
		$hCurrent = htmlspecialchars($current);
		$hDefault = htmlspecialchars($opts['default'] ?? '');
		if (isset($opts['enum'])) {
			// Enum is a select/dropdown/combobox
			$return = '<select id="input-' . $key . '" class="form-control" name="' . $key . '">';
			foreach ($opts['enum'] as $enumValue) {
				$return .= '<option value="' . htmlspecialchars($enumValue) . '"'
					. ($current == $enumValue ? ' selected' : '') . '>'
					. htmlspecialchars(Dictionary::translateFile('panel-params', $key . '_enum_' . $enumValue, false) ?: $enumValue)
					. '</option>';
			}
			$return .= '</select>';
		} elseif ($varType === 'int') {
			if (($opts['slider'] ?? false) && isset($opts['min']) && isset($opts['max'])) {
				// Slider requested
				$return = '<div class="row input-slider"><div class="col-sm-10 col-xs-9">'
					. '<input class="form-control" id="input-' . $key . '" type="range" min="' . $opts['min']
					. '" max="' . $opts['max'] . '" name="' . $key . '" value="' . $hCurrent . '"';
				if (isset($opts['step'])) {
					$return .= ' step="' . $opts['step'] . '"';
				}
				$return .= '></div><div class="col-sm-2 col-xs-3">'
					. '<span class="slider-value">' . $hCurrent . '</span>' . htmlspecialchars($opts['slider'])
					. '</div></div>';
			} else {
				// Normal text field for numbers
				$return = '<input id="input-' . $key . '" class="form-control" type="number" name="' . $key . '" value="'
					. $hCurrent . '"'
					. ' placeholder="' . $hDefault . '"';
				if (isset($opts['min'])) {
					$return .= ' min="' . $opts['min'] . '"';
				}
				if (isset($opts['max'])) {
					$return .= ' max="' . $opts['max'] . '"';
				}
				$return .= '>';
			}
		} elseif ($varType === 'bool') {
			$return = '<div class="checkbox"><input id="input-' . $key . '" type="checkbox" name="' . $key . '" value="1"'
				. ($current ? ' checked' : '') . '><label></label></div>';
		} elseif ($varType === 'string') {
			$return = '<input id="input-' . $key . '" class="form-control" type="text" name="' . $key . '" value="'
				. $hCurrent . '"'
				. ' placeholder="' . $hDefault . '">';
		} else {
			ErrorHandler::traceError("Invalid variable type: '$varType'");
		}
		return $return;
	}

	/**
	 * Gets the calendar of the given location IDs.
	 *
	 * @param int[] $idList list with the location ids.
	 * @param ?int $deadline null = no timeout, otherwise a unix timestamp until which we expect function to return
	 * @return array Calendar.
	 */
	public static function getCalendar(array $idList, ?int $deadline = null): array
	{
		if (empty($idList))
			return [];

		if ($deadline !== null && $deadline <= time()) {
			// Deadline in the past, use cached data exclusively
			$resultArray = [];
			$res = Database::simpleQuery("SELECT locationid, calendar FROM locationinfo_locationconfig
					WHERE Length(calendar) > 10
					  AND lastcalendarupdate > UNIX_TIMESTAMP() - 86400*3
					  AND locationid IN (:lid)",
				['lid' => $idList]);
			foreach ($res as $row) {
				$resultArray[] = [
					'id' => (int)$row['locationid'],
					'calendar' => json_decode($row['calendar'], true),
				];
			}
			return $resultArray;
		}

		// Build SQL query for multiple ids.
		$query = "SELECT l.locationid, l.serverid, l.serverlocationid, s.servertype, s.credentials
				FROM `locationinfo_locationconfig` AS l
				INNER JOIN locationinfo_coursebackend AS s ON (s.serverid = l.serverid)
				WHERE l.locationid IN (:idlist)";
		$rows = Database::queryAll($query, array('idlist' => array_values($idList)));
		return self::getCalendarCommon($rows, $deadline);
	}

	/**
	 * Fetch all calendars from backend that seem to be actively in use by a running frontend panel,
	 * and are about to expire. This should reduce load times next time the panel requests an update,
	 * as it ensures the data can be served from cache.
	 */
	public static function refreshStaleButActiveCalendars()
	{
		$NOW = time();
		// Get all calendars where 'lastuse' was in past ~6 minutes
		$rows = Database::queryAll("SELECT l.locationid, l.lastcalendarupdate, l.serverid, l.serverlocationid,
       			s.servertype, s.credentials
				FROM `locationinfo_locationconfig` AS l
				INNER JOIN locationinfo_coursebackend AS s ON (s.serverid = l.serverid)
				WHERE l.lastuse > :cutoff AND l.lastuse > l.lastcalendarupdate", ['cutoff' => $NOW - 400]);
		foreach (array_keys($rows) as $i) {
			$row = $rows[$i];
			$serverInstance = CourseBackend::getInstance($row['servertype']);
			if ($serverInstance === false)
				continue;
			$secsSinceLastFetch = $NOW - $row['lastcalendarupdate'];
			// Must hold:
			// Last update was between max cache time and opportunistic refresh time
			// Also refresh time has to be at least 10 minutes
			if ($serverInstance->getRefreshTime() < 600
					|| $secsSinceLastFetch > $serverInstance->getCacheTime()
					|| $secsSinceLastFetch < $serverInstance->getRefreshTime()) {
				// Nope
				unset($rows[$i]);
			}
		}
		self::getCalendarCommon($rows, -1);
	}

	/**
	 * @param ?int $deadline accepts special value -1 to ignore cache and always fetch
	 */
	private static function getCalendarCommon(array $wantedCalendars, ?int $deadline): array
	{
		$serverList = [];
		foreach ($wantedCalendars as $cal) {
			if (!isset($serverList[$cal['serverid']])) {
				$serverList[$cal['serverid']] = [
					'credentials' => (array)json_decode($cal['credentials'], true),
					'type' => $cal['servertype'],
					'idlist' => []
				];
			}
			$serverList[$cal['serverid']]['idlist'][] = $cal['locationid'];
		}

		$resultArray = [];
		foreach ($serverList as $serverid => $server) {
			$serverInstance = CourseBackend::getInstance($server['type']);
			if ($serverInstance === false) {
				EventLog::warning('Cannot fetch schedule (' . implode(', ', $server['idlist']) . ')'
					. ': Backend type ' . $server['type'] . ' unknown. Disabling location.');
				Database::exec("UPDATE locationinfo_locationconfig SET serverid = NULL WHERE locationid IN (:lid)",
					['lid' => $server['idlist']]);
				continue;
			}
			if ($serverInstance->setCredentials($serverid, $server['credentials'])) {
				$calendarFromBackend = $serverInstance->fetchSchedule($server['idlist'], $deadline);
			} else {
				$calendarFromBackend = [];
			}

			LocationInfo::setServerError($serverid, $serverInstance->getErrors());

			foreach ($calendarFromBackend as $locationId => $calendar) {
				$resultArray[] = [
					'id' => (int)$locationId,
					'calendar' => $calendar,
				];
			}
		}
		return $resultArray;
	}

	/**
	 * Get all calendars. Can update or fetch from cache. If $deadline is NULL, all calendars that are stale will
	 * be fetched from the according backends. Otherwise, $deadline is expected to be a UNIX TIMESTAMP until which
	 * we request the function to return, trying to update as many stale calendars as possible during that time,
	 * returning cached values for all that weren't updated. Passing a timestamp in the past (e.g. 0) ensures
	 * that all calendars will be served from cache, regardless of age.
	 * @param ?int $deadline null = no timeout, otherwise a unix timestamp until which we expect to return
	 */
	public static function getAllCalendars(?int $deadline = null): array
	{
		$locations = Database::queryColumnArray("SELECT locationid FROM location");
		$calendars = [];
		foreach (LocationInfo::getCalendar($locations, $deadline) as $cal) {
			if (empty($cal['calendar']))
				continue;
			$calendars[$cal['id']] = $cal['calendar'];
		}
		return $calendars;
	}

	public static function extractCurrentEvent(array $calendar): string
	{
		$NOW = time();
		foreach ($calendar as $event) {
			$start = strtotime($event['start']);
			$end = strtotime($event['end']) + 60;
			if ($NOW >= $start && $NOW <= $end)
				return $event['title'];
		}
		return '';
	}


	/**
	 * Transform legacy url filter config if found, remove no-op filter setups.
	 * @param array $config The configuration array to be cleaned up. By reference.
	 */
	public static function cleanupUrlFilter(array &$config): void
	{
		// First, simple trimming of white-space around the list, and making sure the keys exist
		$config['blacklist'] = trim($config['blacklist'] ?? '');
		$config['whitelist'] = trim($config['whitelist'] ?? '');
		if (empty($config['blacklist']) && empty($config['whitelist'])) {
			// Mangle non-upgraded configurations: They only have one list and a bool specifying if it's a black- or whitelist
			if (!empty($config['urllist'])) {
				if ($config['iswhitelist'] ?? false) {
					$config['whitelist'] = str_replace(' ', "\n", $config['urllist']);
				} else {
					$config['blacklist'] = str_replace(' ', "\n", $config['urllist']);
				}
				unset($config['urllist'], $config['iswhitelist']);
			}
		} elseif ((empty($config['blacklist']) || self::isAnyUrlMatch($config['blacklist']))
				&& self::isAnyUrlMatch($config['whitelist'])) {
			// Blocking everything/nothing and allowing everything is a no-op for all three browsers, so clear both lists
			$config['blacklist'] = '';
			$config['whitelist'] = '';
		}
		$config['blacklist'] = preg_replace('/\r?\n/', "\r\n", $config['blacklist']);
		$config['whitelist'] = preg_replace('/\r?\n/', "\r\n", $config['whitelist']);
	}

	/**
	 * Check if the given pattern would be interpreted as matching any URL.
	 * @param string $url The URL to check
	 */
	private static function isAnyUrlMatch(string $url): bool
	{
		return $url === '*' || $url === '*://*' || $url === '*://*/' || $url === '*://*/*';
	}

}