<?php
require_once('include/bittorrent_announce.php');
require_once('include/benc.php');
dbconn_announce();
//1. BLOCK ACCESS WITH WEB BROWSERS AND CHEATS!
$agent = $_SERVER["HTTP_USER_AGENT"];
block_browser();
//2. GET ANNOUNCE VARIABLES
// get string type passkey, info_hash, peer_id, event, ip from client
foreach (array("passkey","info_hash","peer_id","event") as $x)
{
	if(isset($_GET["$x"]))
	$GLOBALS[$x] = $_GET[$x];
}
// get integer type port, downloaded, uploaded, left from client
foreach (array("port","downloaded","uploaded","left","compact","no_peer_id") as $x)
{
	$GLOBALS[$x] = intval($_GET[$x] ?? 0);
}
//check info_hash, peer_id and passkey
foreach (array("passkey","info_hash","peer_id","port","downloaded","uploaded","left") as $x)
	if (!isset($x)) err("Missing key: $x");
foreach (array("info_hash","peer_id") as $x)
	if (strlen($GLOBALS[$x]) != 20) err("Invalid $x (" . strlen($GLOBALS[$x]) . " - " . rawurlencode($GLOBALS[$x]) . ")");
if (strlen($passkey) != 32) err("Invalid passkey (" . strlen($passkey) . " - $passkey)");

//4. GET IP AND CHECK PORT
$ip = getip();	// avoid to get the spoof ip from some agent
if (!$port || $port > 0xffff)
	err("invalid port");
if (!ip2long($ip)) //Disable compact announce with IPv6
	$compact = 0;

// check port and connectable
if (portblacklisted($port))
	err("Port $port is blacklisted.");

//5. GET PEER LIST
// Number of peers that the client would like to receive from the tracker.This value is permitted to be zero. If omitted, typically defaults to 50 peers.
$rsize = 50;
foreach(array("numwant", "num want", "num_want") as $k)
{
	if (isset($_GET[$k]))
	{
		$rsize = intval($_GET[$k] ?? 0);
		break;
	}
}

// set if seeder based on left field
$seeder = ($left == 0) ? "yes" : "no";

// check passkey
if (!$az = $Cache->get_value('user_passkey_'.$passkey.'_content')){
	$res = sql_query("SELECT id, downloadpos, enabled, uploaded, downloaded, class, parked, clientselect, showclienterror FROM users WHERE passkey=". sqlesc($passkey)." LIMIT 1");
	$az = mysql_fetch_array($res);
	$Cache->cache_value('user_passkey_'.$passkey.'_content', $az, 950);
}
if (!$az) err("Invalid passkey! Re-download the .torrent from $BASEURL");
$userid = intval($az['id'] ?? 0);

//3. CHECK IF CLIENT IS ALLOWED
$clicheck_res = check_client($peer_id,$agent,$client_familyid);
if($clicheck_res){
	if ($az['showclienterror'] == 'no')
	{
		sql_query("UPDATE users SET showclienterror = 'yes' WHERE id = ".sqlesc($userid));
		$Cache->delete_value('user_passkey_'.$passkey.'_content');
	}
	err($clicheck_res);
}
elseif ($az['showclienterror'] == 'yes'){
	$USERUPDATESET[] = "showclienterror = 'no'";
	$Cache->delete_value('user_passkey_'.$passkey.'_content');
}

// check torrent based on info_hash
if (!$torrent = $Cache->get_value('torrent_hash_'.$info_hash.'_content')){
	$res = sql_query("SELECT id, owner, sp_state, seeders, leechers, UNIX_TIMESTAMP(added) AS ts, banned FROM torrents WHERE " . hash_where("info_hash", $info_hash));
	$torrent = mysql_fetch_array($res);
	$Cache->cache_value('torrent_hash_'.$info_hash.'_content', $torrent, 350);
}
if (!$torrent) err("torrent not registered with this tracker");
elseif ($torrent['banned'] == 'yes' && $az['class'] < $seebanned_class) err("torrent banned");
// select peers info from peers table for this torrent
$torrentid = $torrent["id"];
$numpeers = $torrent["seeders"]+$torrent["leechers"];

if ($seeder == 'yes'){ //Don't report seeds to other seeders
	$only_leech_query = " AND seeder = 'no' ";
	$newnumpeers = $torrent["leechers"];
}
else{
	$only_leech_query = "";
	$newnumpeers = $numpeers;
}
if ($newnumpeers > $rsize)
	$limit = " ORDER BY RAND() LIMIT $rsize";
else $limit = "";
$announce_wait = 30;

$fields = "seeder, peer_id, ip, port, uploaded, downloaded, (".TIMENOW." - UNIX_TIMESTAMP(last_action)) AS announcetime, UNIX_TIMESTAMP(prev_action) AS prevts";
$peerlistsql = "SELECT ".$fields." FROM peers WHERE torrent = ".$torrentid." AND connectable = 'yes' ".$only_leech_query.$limit;
$res = sql_query($peerlistsql);

$real_annnounce_interval = $announce_interval;
if ($anninterthreeage && ($anninterthree > $announce_wait) && (TIMENOW - $torrent['ts']) >= ($anninterthreeage * 86400))
$real_annnounce_interval = $anninterthree;
elseif ($annintertwoage && ($annintertwo > $announce_wait) && (TIMENOW - $torrent['ts']) >= ($annintertwoage * 86400))
$real_annnounce_interval = $annintertwo;

$resp = "d" . benc_str("interval") . "i" . $real_annnounce_interval . "e" . benc_str("min interval") . "i" . $announce_wait . "e". benc_str("complete") . "i" . $torrent["seeders"] . "e" . benc_str("incomplete") . "i" . $torrent["leechers"] . "e" . benc_str("peers");

$peer_list = "";
unset($self);
// bencoding the peers info get for this announce
while ($row = mysql_fetch_assoc($res))
{
	$row["peer_id"] = hash_pad($row["peer_id"]);

	// $peer_id is the announcer's peer_id while $row["peer_id"] is randomly selected from the peers table
	if ($row["peer_id"] === $peer_id)
	{
		$self = $row;
		continue;
	}
if ($compact == 1){
	$longip = ip2long($row['ip']);
	if ($longip) //Ignore ipv6 address
		$peer_list .= pack("Nn", sprintf("%d",$longip), $row['port']);
}
elseif ($no_peer_id == 1)
	$peer_list .= "d" .
	benc_str("ip") . benc_str($row["ip"]) .
	benc_str("port") . "i" . $row["port"] . "e" .
	"e";
else
	$peer_list .= "d" .
	benc_str("ip") . benc_str($row["ip"]) .
	benc_str("peer id") . benc_str($row["peer_id"]) .
	benc_str("port") . "i" . $row["port"] . "e" .
	"e";
}
if ($compact == 1)
$resp .= benc_str($peer_list);
else
$resp .= "l".$peer_list."e";

$resp .= "e";
$selfwhere = "torrent = $torrentid AND " . hash_where("peer_id", $peer_id);

//no found in the above random selection
if (!isset($self))
{
	$res = sql_query("SELECT $fields FROM peers WHERE $selfwhere LIMIT 1");
	$row = mysql_fetch_assoc($res);
	if ($row)
	{
		$self = $row;
	}
}

// min announce time
if(isset($self) && $self['prevts'] > (TIMENOW - $announce_wait))
	err('There is a minimum announce time of ' . $announce_wait . ' seconds');

// current peer_id, or you could say session with tracker not found in table peers
if (!isset($self))
{
	$valid = @mysql_fetch_row(@sql_query("SELECT COUNT(*) FROM peers WHERE torrent=$torrentid AND userid=" . sqlesc($userid)));
	if ($valid[0] >= 1 && $seeder == 'no') err("You already are downloading the same torrent. You may only leech from one location at a time.");
	if ($valid[0] >= 3 && $seeder == 'yes') err("You cannot seed the same torrent from more than 3 locations.");

	if ($az["enabled"] == "no")
	err("Your account is disabled!");
	elseif ($az["parked"] == "yes")
	err("Your account is parked! (Read the FAQ)");
	elseif ($az["downloadpos"] == "no")
	err("Your downloading priviledges have been disabled! (Read the rules)");

	if ($az["class"] < UC_VIP)
	{
		$ratio = (($az["downloaded"] > 0) ? ($az["uploaded"] / $az["downloaded"]) : 1);
		$gigs = $az["downloaded"] / (1024*1024*1024);
		if ($waitsystem == "yes")
		{
			if($gigs > 10)
			{
				$elapsed = strtotime(date("Y-m-d H:i:s")) - $torrent["ts"];
				if ($ratio < 0.4) $wait = 24;
				elseif ($ratio < 0.5) $wait = 12;
				elseif ($ratio < 0.6) $wait = 6;
				elseif ($ratio < 0.8) $wait = 3;
				else $wait = 0;

				if ($elapsed < $wait)
				err("Your ratio is too low! You need to wait " . mkprettytime($wait * 3600 - $elapsed) . " to start, please read $BASEURL/faq.php#id46 for details");
			}
		}
		if ($maxdlsystem == "yes")
		{
			if($gigs > 10)
			if ($ratio < 0.5) $max = 1;
			elseif ($ratio < 0.65) $max = 2;
			elseif ($ratio < 0.8) $max = 3;
			elseif ($ratio < 0.95) $max = 4;
			else $max = 0;
			if ($max > 0)
			{
				$res = sql_query("SELECT COUNT(*) AS num FROM peers WHERE userid='$userid' AND seeder='no'") or err("Tracker error 5");
				$row = mysql_fetch_assoc($res);
				if ($row['num'] >= $max) err("Your slot limit is reached! You may at most download $max torrents at the same time, please read $BASEURL/faq.php#id66 for details");
			}
		}
	}
}
else // continue an existing session
{
	$upthis = $trueupthis = max(0, $uploaded - $self["uploaded"]);
	$downthis = $truedownthis = max(0, $downloaded - $self["downloaded"]);
	$announcetime = ($self["seeder"] == "yes" ? "seedtime = seedtime + $self[announcetime]" : "leechtime = leechtime + $self[announcetime]");
	$is_cheater = false;
	
	if ($cheaterdet_security){
		if ($az['class'] < $nodetect_security && $self['announcetime'] > 10)
		{
			$is_cheater = check_cheater($userid, $torrent['id'], $upthis, $downthis, $self['announcetime'], $torrent['seeders'], $torrent['leechers']);
		}
	}

	if (!$is_cheater && ($trueupthis > 0 || $truedownthis > 0))
	{
		$global_promotion_state = get_global_sp_state();
		if($global_promotion_state == 1)// Normal, see individual torrent
		{
			if($torrent['sp_state']==3) //2X
			{
				$USERUPDATESET[] = "uploaded = uploaded + 2*$trueupthis";
				$USERUPDATESET[] = "downloaded = downloaded + $truedownthis";
			}
			elseif($torrent['sp_state']==4) //2X Free
			{
				$USERUPDATESET[] = "uploaded = uploaded + 2*$trueupthis";
			}
			elseif($torrent['sp_state']==6) //2X 50%
			{
				$USERUPDATESET[] = "uploaded = uploaded + 2*$trueupthis";
				$USERUPDATESET[] = "downloaded = downloaded + $truedownthis/2";
			}
			else{
				if ($torrent['owner'] == $userid && $uploaderdouble_torrent > 0)
					$upthis = $trueupthis * $uploaderdouble_torrent;

				if($torrent['sp_state']==2) //Free
				{
					$USERUPDATESET[] = "uploaded = uploaded + $upthis";
				}
				elseif($torrent['sp_state']==5) //50%
				{
					$USERUPDATESET[] = "uploaded = uploaded + $upthis";
					$USERUPDATESET[] = "downloaded = downloaded + $truedownthis/2";
				}
				elseif($torrent['sp_state']==7) //30%
				{
					$USERUPDATESET[] = "uploaded = uploaded + $upthis";
					$USERUPDATESET[] = "downloaded = downloaded + $truedownthis*3/10";
				}
				elseif($torrent['sp_state']==1) //Normal
				{
					$USERUPDATESET[] = "uploaded = uploaded + $upthis";
					$USERUPDATESET[] = "downloaded = downloaded + $truedownthis";
				}
			}
		}
		elseif($global_promotion_state == 2) //Free
		{
			if ($torrent['owner'] == $userid && $uploaderdouble_torrent > 0)
				$upthis = $trueupthis * $uploaderdouble_torrent;
			$USERUPDATESET[] = "uploaded = uploaded + $upthis";
		}
		elseif($global_promotion_state == 3) //2X
		{
			if ($uploaderdouble_torrent > 2 && $torrent['owner'] == $userid && $uploaderdouble_torrent > 0)
				$upthis = $trueupthis * $uploaderdouble_torrent;
			else $upthis = 2*$trueupthis;
			$USERUPDATESET[] = "uploaded = uploaded + $upthis";
			$USERUPDATESET[] = "downloaded = downloaded + $truedownthis";
		}
		elseif($global_promotion_state == 4) //2X Free
		{
			if ($uploaderdouble_torrent > 2 && $torrent['owner'] == $userid && $uploaderdouble_torrent > 0)
				$upthis = $trueupthis * $uploaderdouble_torrent;
			else $upthis = 2*$trueupthis;
			$USERUPDATESET[] = "uploaded = uploaded + $upthis";
		}
		elseif($global_promotion_state == 5){ // 50%
			if ($torrent['owner'] == $userid && $uploaderdouble_torrent > 0)
				$upthis = $trueupthis * $uploaderdouble_torrent;
			$USERUPDATESET[] = "uploaded = uploaded + $upthis";
			$USERUPDATESET[] = "downloaded = downloaded + $truedownthis/2";
		}
		elseif($global_promotion_state == 6){ //2X 50%
			if ($uploaderdouble_torrent > 2 && $torrent['owner'] == $userid && $uploaderdouble_torrent > 0)
				$upthis = $trueupthis * $uploaderdouble_torrent;
			else $upthis = 2*$trueupthis;
			$USERUPDATESET[] = "uploaded = uploaded + $upthis";
			$USERUPDATESET[] = "downloaded = downloaded + $truedownthis/2";
		}
		elseif($global_promotion_state == 7){ //30%
			if ($torrent['owner'] == $userid && $uploaderdouble_torrent > 0)
				$upthis = $trueupthis * $uploaderdouble_torrent;
			$USERUPDATESET[] = "uploaded = uploaded + $upthis";
			$USERUPDATESET[] = "downloaded = downloaded + $truedownthis*3/10";
		}
	}
}

$dt = sqlesc(date("Y-m-d H:i:s"));
$updateset = array();
// set non-type event
if (!isset($event))
	$event = "";
if (isset($self) && $event == "stopped")
{
	sql_query("DELETE FROM peers WHERE $selfwhere") or err("D Err");
	if (mysql_affected_rows())
	{
		$updateset[] = ($self["seeder"] == "yes" ? "seeders = seeders - 1" : "leechers = leechers - 1");
		sql_query("UPDATE snatched SET uploaded = uploaded + $trueupthis, downloaded = downloaded + $truedownthis, to_go = $left, $announcetime, last_action = ".$dt." WHERE torrentid = $torrentid AND userid = $userid") or err("SL Err 1");
	}
}
elseif(isset($self))
{
	if ($event == "completed")
	{
		//sql_query("UPDATE snatched SET  finished  = 'yes', completedat = $dt WHERE torrentid = $torrentid AND userid = $userid");
		$finished = ", finishedat = ".TIMENOW;
		$finished_snatched = ", completedat = ".$dt . ", finished  = 'yes'";
		$updateset[] = "times_completed = times_completed + 1";
	}

	sql_query("UPDATE peers SET ip = ".sqlesc($ip).", port = $port, uploaded = $uploaded, downloaded = $downloaded, to_go = $left, prev_action = last_action, last_action = $dt, seeder = '$seeder', agent = ".sqlesc($agent)." $finished WHERE $selfwhere") or err("PL Err 1");

	if (mysql_affected_rows())
	{
		if ($seeder <> $self["seeder"])
		$updateset[] = ($seeder == "yes" ? "seeders = seeders + 1, leechers = leechers - 1" : "seeders = seeders - 1, leechers = leechers + 1");
		sql_query("UPDATE snatched SET uploaded = uploaded + $trueupthis, downloaded = downloaded + $truedownthis, to_go = $left, $announcetime, last_action = ".$dt." $finished_snatched WHERE torrentid = $torrentid AND userid = $userid") or err("SL Err 2");
	}
}
else
{
	$sockres = @pfsockopen($ip, $port, $errno, $errstr, 5);
	if (!$sockres)
	{
		$connectable = "no";
	}
	else
	{
		$connectable = "yes";
		@fclose($sockres);
	}
	sql_query("INSERT INTO peers (torrent, userid, peer_id, ip, port, connectable, uploaded, downloaded, to_go, started, last_action, seeder, agent, downloadoffset, uploadoffset, passkey) VALUES ($torrentid, $userid, ".sqlesc($peer_id).", ".sqlesc($ip).", $port, '$connectable', $uploaded, $downloaded, $left, $dt, $dt, '$seeder', ".sqlesc($agent).", $downloaded, $uploaded, ".sqlesc($passkey).")") or err("PL Err 2");

	if (mysql_affected_rows())
	{
		$updateset[] = ($seeder == "yes" ? "seeders = seeders + 1" : "leechers = leechers + 1");
		
		$check = @mysql_fetch_row(@sql_query("SELECT COUNT(*) FROM snatched WHERE torrentid = $torrentid AND userid = $userid"));
		if (!$check['0'])
			sql_query("INSERT INTO snatched (torrentid, userid, ip, port, uploaded, downloaded, to_go, startdat, last_action) VALUES ($torrentid, $userid, ".sqlesc($ip).", $port, $uploaded, $downloaded, $left, $dt, $dt)") or err("SL Err 4");
		else
			sql_query("UPDATE snatched SET to_go = $left, last_action = ".$dt ." WHERE torrentid = $torrentid AND userid = $userid") or err("SL Err 3.1");
	}
}

if (count($updateset)) // Update only when there is change in peer counts
{
	$updateset[] = "visible = 'yes'";
	$updateset[] = "last_action = $dt";
	sql_query("UPDATE torrents SET " . join(",", $updateset) . " WHERE id = $torrentid");
}

if($client_familyid != 0 && $client_familyid != $az['clientselect'])
	$USERUPDATESET[] = "clientselect = ".sqlesc($client_familyid);

if(count($USERUPDATESET) && $userid)
{
	sql_query("UPDATE users SET " . join(",", $USERUPDATESET) . " WHERE id = ".$userid);
}
benc_resp_raw($resp);
?>
