/*       +------------------------------------+
 *       | Inspire Internet Relay Chat Daemon |
 *       +------------------------------------+
 *
 *  InspIRCd: (C) 2002-2011 InspIRCd Development Team
 * See: http://wiki.inspircd.org/Credits
 *
 * This program is free but copyrighted software; see
 *            the file COPYING for details.
 *
 * ---------------------------------------------------
 */

#include "inspircd.h"

#include "main.h"
#include "../spanningtree.h"
#include "utils.h"
#include "treeserver.h"
#include "link.h"
#include "treesocket.h"
#include "resolvers.h"

/** Because most of the I/O gubbins are encapsulated within
 * BufferedSocket, we just call the superclass constructor for
 * most of the action, and append a few of our own values
 * to it.
 */
TreeSocket::TreeSocket(SpanningTreeUtilities* Util, Link* link, Autoconnect* myac, const std::string& ipaddr)
	: Utils(Util), linkID(link->Name), LinkState(CONNECTING), MyRoot(NULL), proto_version(0),
	  sync(this), age(ServerInstance->Time()), NextPing(age + link->Timeout), LastPingWasGood(false)
{
	capab = new CapabData;
	capab->link = link;
	capab->ac = myac;
	capab->capab_phase = 0;
	DoConnect(ipaddr, link->Port, link->Timeout, link->Bind);
	if (!link->Hook.empty())
	{
		IOHookProvider* prov =
		static_cast<IOHookProvider*>(ServerInstance->Modules->FindService(SERVICE_IOHOOK, link->Hook));
		if (!prov)
		{
			SetError("Could not find hook '" + link->Hook + "' for connection to " + linkID);
			return;
		}
		prov->OnClientConnection(this, link->tag);
	}
	SendCapabilities(1);
}

/** When a listening socket gives us a new file descriptor,
 * we must associate it with a socket without creating a new
 * connection. This constructor is used for this purpose.
 */
TreeSocket::TreeSocket(SpanningTreeUtilities* Util, int newfd, ListenSocket* via, irc::sockets::sockaddrs* client, irc::sockets::sockaddrs* server)
	: BufferedSocket(newfd), Utils(Util), LinkState(WAIT_AUTH_1), MyRoot(NULL), proto_version(0),
	  sync(this), age(ServerInstance->Time()), NextPing(age + 30), LastPingWasGood(false)
{
	capab = new CapabData;
	capab->capab_phase = 0;
	linkID = "inbound from " + client->addr();

	SendCapabilities(1);
}

ServerState TreeSocket::GetLinkState()
{
	return this->LinkState;
}

void TreeSocket::CleanNegotiationInfo()
{
	// connect is good, reset the autoconnect block (if used)
	if (capab->ac)
		capab->ac->position = -1;
	delete capab;
	capab = NULL;
}

CullResult TreeSocket::cull()
{
	if (capab && capab->ac)
		Utils->Creator->ConnectServer(capab->ac, false);
	for(size_t i = 0; i < Utils->Connections.size(); i++)
	{
		if (Utils->Connections[i] == this)
		{
			// fast removal from an unsorted vector:
			// replace this element with the last one (nop if we are the last)
			Utils->Connections[i] = Utils->Connections.back();
			// then remove the last element
			Utils->Connections.pop_back();
			break;
		}
	}
	return this->BufferedSocket::cull();
}

TreeSocket::~TreeSocket()
{
	delete capab;
}

/** When an outbound connection finishes connecting, we receive
 * this event, and must send our SERVER string to the other
 * side. If the other side is happy, as outlined in the server
 * to server docs on the inspircd.org site, the other side
 * will then send back its own server string.
 */
void TreeSocket::OnConnected()
{
	if (this->LinkState == CONNECTING)
	{
		ServerInstance->SNO->WriteGlobalSno('l', "Connection to \2%s\2[%s] started.", linkID.c_str(),
			(capab->link->HiddenFromStats ? "<hidden>" : capab->link->IPAddr.c_str()));
		this->SendCapabilities(1);
	}
}

void TreeSocket::OnError(BufferedSocketError e)
{
	if (LinkState != DYING)
	{
		ServerInstance->GlobalCulls->AddItem(this);
		ServerInstance->SNO->WriteGlobalSno('l', "Connection to \002%s\002 failed with error: %s",
			linkID.c_str(), getError().c_str());
		LinkState = DYING;
	}
}

void TreeSocket::SendError(const std::string &errormessage)
{
	WriteLine("ERROR :"+errormessage);
	DoWrite();
	if (LinkState != DYING)
	{
		ServerInstance->GlobalCulls->AddItem(this);
		LinkState = DYING;
	}
	SetError(errormessage);
}

/** This function forces this server to quit, removing this server
 * and any users on it (and servers and users below that, etc etc).
 * It's very slow and pretty clunky, but luckily unless your network
 * is having a REAL bad hair day, this function shouldnt be called
 * too many times a month ;-)
 */
void TreeSocket::SquitServer(std::string &from, TreeServer* Current, int& num_lost_servers, int& num_lost_users)
{
	ServerInstance->Logs->Log("m_spanningtree",DEBUG,"SquitServer for %s from %s",
		Current->GetName().c_str(), from.c_str());
	/* recursively squit the servers attached to 'Current'.
	 * We're going backwards so we don't remove users
	 * while we still need them ;)
	 */
	for (unsigned int q = 0; q < Current->ChildCount(); q++)
	{
		TreeServer* recursive_server = Current->GetChild(q);
		this->SquitServer(from,recursive_server, num_lost_servers, num_lost_users);
	}
	/* Now we've whacked the kids, whack self */
	num_lost_servers++;
	num_lost_users += Current->QuitUsers(from);
}

/** This is a wrapper function for SquitServer above, which
 * does some validation first and passes on the SQUIT to all
 * other remaining servers.
 */
void TreeSocket::Squit(TreeServer* Current, const std::string &reason)
{
	bool LocalSquit = false;

	if ((Current) && (Current != Utils->TreeRoot))
	{
		DelServerEvent(Utils->Creator, Current->GetName());

		parameterlist params;
		params.push_back(Current->GetName());
		params.push_back(":"+reason);
		Utils->DoOneToAllButSender(Current->GetParent()->GetName(),"SQUIT",params,Current->GetName());
		if (Current->GetParent() == Utils->TreeRoot)
		{
			ServerInstance->SNO->WriteGlobalSno('l', "Server \002"+Current->GetName()+"\002 split: "+reason);
			LocalSquit = true;
		}
		else
		{
			ServerInstance->SNO->WriteGlobalSno('L', "Server \002"+Current->GetName()+"\002 split from server \002"+Current->GetParent()->GetName()+"\002 with reason: "+reason);
		}
		int num_lost_servers = 0;
		int num_lost_users = 0;
		std::string from = Current->GetParent()->GetName()+" "+Current->GetName();
		SquitServer(from, Current, num_lost_servers, num_lost_users);
		ServerInstance->SNO->WriteToSnoMask(LocalSquit ? 'l' : 'L', "Netsplit complete, lost \002%d\002 user%s on \002%d\002 server%s.",
			num_lost_users, num_lost_users != 1 ? "s" : "", num_lost_servers, num_lost_servers != 1 ? "s" : "");
		Current->Tidy();
		Current->GetParent()->DelChild(Current);
		Current->cull();
		delete Current;
		if (Current == MyRoot)
		{
			MyRoot = NULL;
			SetError("SQUIT: " + reason);
		}
	}
	else
		ServerInstance->Logs->Log("m_spanningtree",DEFAULT,"Squit from unknown server");
}

/** This function is called when we receive data from a remote
 * server.
 */
void TreeSocket::OnDataReady()
{
	Utils->Creator->loopCall = true;
	std::string line;
	while (GetNextLine(line))
	{
		std::string::size_type rline = line.find('\r');
		if (rline != std::string::npos)
			line = line.substr(0,rline);
		if (line.find('\0') != std::string::npos)
		{
			SendError("Read null character from socket");
			break;
		}
		ProcessLine(line);
		if (!getError().empty())
			break;
	}
	if (LinkState != CONNECTED && recvq.length() > 4096)
		SendError("RecvQ overrun (line too long)");
	Utils->Creator->loopCall = false;
}