<?php

class RemoteAccess
{

	const PROP_ALLOWED_VNC_NET = 'remoteaccess.allowedvncaccess';

	const PROP_TRY_VIRT_HANDOVER = 'remoteaccess.virthandover';

	const PROP_VNC_PORT = 'remoteaccess.vncport';

	const PROP_PLUGIN_VERSION = 'remoteaccess.plugin-version';

	/**
	 * Get a list of locationIds where remote access is enabled. If $filterOverridden is true,
	 * the list will not contain any locations where remote access is disabled via location override.
	 * @param int $group Group to get locations for, or '0' for all locations
	 * @param bool $filterOverridden iff true, remove any locations where remote access is currently disabled
	 */
	public static function getEnabledLocations(int $group = 0, bool $filterOverridden = true): array
	{
		if ($group === 0) {
			$list = Database::queryColumnArray("SELECT DISTINCT rxl.locationid FROM remoteaccess_x_location rxl
				INNER JOIN remoteaccess_group g ON (g.groupid = rxl.groupid AND g.active = 1)");
		} else {
			$list = Database::queryColumnArray("SELECT DISTINCT locationid FROM remoteaccess_x_location
				WHERE groupid = :gid", ['gid' => $group]);
		}
		if (!$filterOverridden || !Module::isAvailable('rebootcontrol'))
			return $list;
		return array_filter($list, function (int $lid) {
			$mode = Scheduler::getLocationOptions($lid)['ra-mode'];
			return ($mode !== Scheduler::RA_NEVER
				&& ($mode !== Scheduler::RA_SELECTIVE || !OpeningTimes::isRoomOpen($lid, 5, 5)));
		});
	}

	public static function ensureMachinesRunning()
	{
		if (!Module::isAvailable('rebootcontrol')) {
			error_log("Not waking remote access machines: rebootcontrol missing");
			return;
		}

		$res = Database::simpleQuery("SELECT rg.groupid, rg.groupname, rg.wolcount,
			GROUP_CONCAT(rxl.locationid) AS locs
			FROM remoteaccess_group rg
			INNER JOIN remoteaccess_x_location rxl USING (groupid)
			WHERE rg.active = 1
			GROUP BY groupid");

		// Consider machines we tried to wake in the past 90 seconds as online
		$wolDeadline = time() - 90;
		foreach ($res as $row) {
			$wantNum = $row['wolcount'];
			// This can't really be anything but a CSV list, but better be safe
			$locs = preg_replace('/[^0-9,]/', '', $row['locs']);
			if (!empty($locs)) {
				// Filter out locations for which remote-access is disabled
				$locArray = explode(',', $locs);
				$locArray = array_filter($locArray, function (int $lid) {
					$mode = Scheduler::getLocationOptions($lid)['ra-mode'];
					return ($mode !== Scheduler::RA_NEVER
						&& ($mode !== Scheduler::RA_SELECTIVE || !OpeningTimes::isRoomOpen($lid, 5, 5)));
				});
				$locs = implode(',', $locArray);
			}
			if ($wantNum > 0 && !empty($locs)) {
				$active = Database::queryFirst("SELECT Count(*) AS cnt FROM machine m
					INNER JOIN remoteaccess_machine rm USING (machineuuid)
					WHERE m.locationid IN ($locs) AND (m.state = 'IDLE' OR rm.woltime > $wolDeadline)");
				$active = ($active['cnt'] ?? 0);
				$wantNum -= $active;
			}
			if ($wantNum > 0) {
				$numFailed = self::tryWakeMachines($locs, $wantNum);
			} else {
				$numFailed = 0;
			}
			Database::exec("UPDATE remoteaccess_group SET unwoken = :num WHERE groupid = :groupid",
				['num' => $numFailed, 'groupid' => $row['groupid']]);
		}
	}

	private static function tryWakeMachines(string $locs, int $num): int
	{
		if (empty($locs))
			return $num;
		$res = Database::simpleQuery("SELECT m.machineuuid, m.macaddr, m.clientip, m.locationid FROM machine m
				LEFT JOIN remoteaccess_machine rm USING (machineuuid)
				WHERE m.locationid IN ($locs) AND m.state IN ('OFFLINE', 'STANDBY')
				ORDER BY rm.woltime ASC");
		$NOW = time();
		while ($num > 0) {
			$list = [];
			for ($i = 0; $i < $num && ($row = $res->fetch()); ++$i) {
				$list[] = $row;
				Database::exec("INSERT INTO remoteaccess_machine (machineuuid, password, woltime)
						VALUES (:uuid, NULL, :now)
						ON DUPLICATE KEY UPDATE woltime = VALUES(woltime)",
					['uuid' => $row['machineuuid'], 'now' => $NOW]);
			}
			if (empty($list))
				break; // No more clients in this location
			RebootControl::wakeMachines($list, $fails);
			$num -= (count($list) - count($fails));
			if (!empty($fails)) {
				$failIds = ArrayUtil::flattenByKey($fails, 'machineuuid');
				// Reduce time so they won't be marked as wol_in_progress
				Database::exec('UPDATE remoteaccess_machine SET woltime = :faketime WHERE machineuuid IN (:fails)',
					['faketime' => $NOW - 95, 'fails' => $failIds]);
			}
		}
		return $num;
	}

}