<?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';

	public static function getEnabledLocations($group = 0)
	{
		if ($group === 0) {
			return 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)");
		}
		return Database::queryColumnArray("SELECT DISTINCT locationid FROM remoteaccess_x_location
				WHERE groupid = :gid", ['gid' => $group]);
	}

	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;
		// Keep track of locations where we sent a WOL to clients, so we don't wake too many machines in locations
		// that appear in multiple groups
		$locationDone = [];
		foreach ($res as $row) {
			// This can't really be anything but a CSV list, but better be safe
			$locs = preg_replace('/[^0-9,]/', '', $row['locs']);
			if (empty($locs))
				continue;
			$wantedCount = $row['wolcount'];
			// Account for machines in the same location(s) already woken in a previous loop iteration
			foreach (explode(',', $locs) as $lid) {
				$wantedCount -= ($locationDone[$lid] ?? 0);
			}
			// Nothing to do?
			if ($wantedCount <= 0)
				continue;
			// Subtract number of idle machines in those locations, or machines that have
			// received a WOL in the past $wolDeadline (90) seconds.
			$active = Database::queryFirst("SELECT Count(*) AS cnt FROM machine m
					INNER JOIN remoteaccess_machine rm USING (machineuuid)
					WHERE m.locationid IN ($locs) AND (m.state = 'IDLE' OR rm.woltime > $wolDeadline)");
			$active = ($active['cnt'] ?? 0);
			$wantedCount -= $active;
			if ($wantedCount <= 0)
				continue;
			$wokenMachines = self::tryWakeMachines($locs, $wantedCount);
			// Update our lookup table of locations and number of machines woken up in them for additional iterations
			if (!empty($wokenMachines)) {
				$locations = array_count_values($wokenMachines);
				foreach ($locations as $lid => $count) {
					$locationDone[$lid] = ($locationDone[$lid] ?? 0) + $count;
				}
			}
		}
	}

	private static function tryWakeMachines(string $locs, int $num): array
	{
		$res = Database::simpleQuery("SELECT m.machineuuid, m.macaddr, m.clientip, m.locationid FROM machine m
				LEFT JOIN remoteaccess_machine rm USING (machineuuid)
				WHERE m.locationid IN ($locs) AND m.state IN ('OFFLINE', 'STANDBY')
				ORDER BY rm.woltime ASC");
		$NOW = time();
		// List of machines we did successfully try to send a WOL to
		$retval = [];
		// Loop while we still have machines to wake
		while ($num > 0) {
			$list = [];
			// Try to gather as many machines as required
			for ($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);
			$triedKv = array_column($list, 'locationid', 'machineuuid');
			// Remove failed from list, flatten to list of machineuuid => location for return
			foreach (array_column($fails, 'machineuuid') as $failMachineUuid) {
				unset($triedKv[$failMachineUuid]);
			}
			$retval += $triedKv;
			// Now reduce $num by how many machines were actually reachable, so we keep going in case there were 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 $retval;
	}

}