/*
 * Copyright (C) 2004-2008  See the AUTHORS file for details.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published
 * by the Free Software Foundation.
 *
 * Secure chat system
 * Author: imaginos <imaginos@imaginos.net>
 */

#define REQUIRESSL

#include "User.h"
#include "znc.h"
#include <sstream>

using std::pair;
using std::stringstream;

class CSChat;

class CRemMarkerJob : public CTimer
{
public:
	CRemMarkerJob(CModule* pModule, unsigned int uInterval, unsigned int uCycles, const CString& sLabel,
			const CString& sDescription)
		: CTimer(pModule, uInterval, uCycles, sLabel, sDescription) {}

	virtual ~CRemMarkerJob() {}
	void SetNick(const CString & sNick)
	{
		m_sNick = sNick;
	}

protected:
	virtual void RunJob();
	CString		m_sNick;
};

class CSChatSock : public Csock
{
public:
	CSChatSock(CSChat *pMod) : Csock()
	{
		m_pModule = pMod;
	}
	CSChatSock(int itimeout = 60) : Csock(itimeout)
	{
		m_pModule = NULL;
		EnableReadLine();
	}
	CSChatSock(const CS_STRING & sHost, u_short iPort, int iTimeout = 60)
		: Csock(sHost, iPort, iTimeout)
	{
		m_pModule = NULL;
		EnableReadLine();
	}

	virtual Csock *GetSockObj(const CS_STRING & sHostname, u_short iPort)
	{
		CSChatSock *p = new CSChatSock(sHostname, iPort);
		p->SetModule(m_pModule);
		p->SetChatNick(m_sChatNick);
		p->SetSockName(GetSockName() + "::" + m_sChatNick);
		return(p);
	}

	virtual bool ConnectionFrom(const CS_STRING & sHost, u_short iPort)
	{
		Close();	// close the listener after the first connection
		return(true);
	}

	virtual void Connected();
	virtual void Timeout();

	void SetModule(CSChat *p)
	{
		m_pModule = p;
	}
	void SetChatNick(const CString & sNick)
	{
		m_sChatNick = sNick;
	}

	const CString & GetChatNick() const { return(m_sChatNick); }

	virtual void ReadLine(const CS_STRING & sLine);
	virtual void Disconnected();

	virtual void AddLine(const CString & sLine)
	{
		m_vBuffer.insert(m_vBuffer.begin(), sLine);
		if (m_vBuffer.size() > 200)
			m_vBuffer.pop_back();
	}

	virtual void DumpBuffer()
	{
		for (vector<CS_STRING>::reverse_iterator it = m_vBuffer.rbegin(); it != m_vBuffer.rend(); it++)
			ReadLine(*it);

		m_vBuffer.clear();
	}

private:
	CSChat 					*m_pModule;
	CString					m_sChatNick;
	vector<CS_STRING>		m_vBuffer;
};

class CSChat : public CModule
{
public:
	MODCONSTRUCTOR(CSChat) {}
	virtual ~CSChat() { CleanSocks(); }

	virtual bool OnLoad(const CString & sArgs, CString & sMessage)
	{
		m_sPemFile = sArgs;

		if (m_sPemFile.empty())
		{
			m_sPemFile = CZNC::Get().GetPemLocation();
		}

		if (!CFile::Exists(m_sPemFile)) {
			sMessage = "Unable to load pem file [" + m_sPemFile + "]";
			return false;
		}

		return true;
	}

	virtual void OnUserAttached()
	{
		CString sName = "SCHAT::" + m_pUser->GetUserName();
		for (u_int a = 0; a < m_pManager->size(); a++)
		{
			if ((*m_pManager)[a]->GetSockName() != sName.c_str() ||
					((*m_pManager)[a]->GetType() == CSChatSock::LISTENER))
				continue;

			CSChatSock *p = (CSChatSock *)(*m_pManager)[a];
			p->DumpBuffer();
		}
	}

	void CleanSocks()
	{
		CString sName = "SCHAT::" + m_pUser->GetUserName();
		for (u_int a= 0; a < m_pManager->size(); a++)
		{
			if ((*m_pManager)[a]->GetSockName() == sName)
				m_pManager->DelSock(a--);
		}
	}

	virtual EModRet OnUserRaw(CString & sLine)
	{
		if (sLine.CaseCmp("schat ", 6) == 0)
		{
			OnModCommand("chat " + sLine.substr(6));
			return(HALT);

		} else if (sLine.CaseCmp("schat") == 0)
		{
			PutModule("SChat User Area ...");
			OnModCommand("help");
			return(HALT);

		}

		return(CONTINUE);
	}

	virtual void OnModCommand(const CString& sCommand)
	{
		CString sCom, sArgs;

		sCom = sCommand.Token(0);
		sArgs = sCommand.Token(1, true);

		if ((sCom.CaseCmp("chat") == 0) && (!sArgs.empty())) {
			CString sSockName = "SCHAT::" + m_pUser->GetUserName();
			CString sNick = "(s)" + sArgs;
			for (u_int a= 0; a < m_pManager->size(); a++)
			{
				if ((*m_pManager)[a]->GetSockName() != sSockName)
					continue;

				CSChatSock *pSock = (CSChatSock *)(*m_pManager)[a];
				if (pSock->GetChatNick().CaseCmp(sNick.c_str()) == 0)
				{
					PutModule("Already Connected to [" + sArgs + "]");
					return;
				}
			}

			CSChatSock *pSock = new CSChatSock;
			pSock->SetCipher("HIGH");
			pSock->SetPemLocation(m_sPemFile);
			pSock->SetModule(this);
			pSock->SetChatNick(sNick);

			u_short iPort = m_pManager->ListenRand(sSockName, m_pUser->GetLocalIP(), true,
					SOMAXCONN, pSock, 60);

			if (iPort == 0)
			{
				PutModule("Failed to start chat!");
				return;
			}

			stringstream s;
			s << "PRIVMSG " << sArgs << " :\001";
			s << "DCC SCHAT chat ";
			s << CUtils::GetLongIP(m_pUser->GetLocalIP());
			s << " " << iPort << "\001";

			PutIRC(s.str());

		} else if (sCom.CaseCmp("list") == 0)
		{
			CString sName = "SCHAT::" + m_pUser->GetUserName();
			CTable Table;
			Table.AddColumn("Nick");
			Table.AddColumn("Created");
			Table.AddColumn("Host");
			Table.AddColumn("Port");
			Table.AddColumn("Status");
			Table.AddColumn("Cipher");
			for (u_int a= 0; a < m_pManager->size(); a++)
			{
				if ((*m_pManager)[a]->GetSockName() != sName)
					continue;

				Table.AddRow();

				CSChatSock *pSock = (CSChatSock *)(*m_pManager)[a];
				Table.SetCell("Nick", pSock->GetChatNick());
				unsigned long long iStartTime = pSock->GetStartTime();
				time_t iTime = iStartTime / 1000;
				char *pTime = ctime(&iTime);
				if (pTime)
				{
					CString sTime = pTime;
					sTime.Trim();
					Table.SetCell("Created", sTime);
				}

				if (pSock->GetType() != CSChatSock::LISTENER)
				{
					Table.SetCell("Status", "Established");
					Table.SetCell("Host", pSock->GetRemoteIP());
					Table.SetCell("Port", CString(pSock->GetRemotePort()));
					SSL_SESSION *pSession = pSock->GetSSLSession();
					if ((pSession) && (pSession->cipher) && (pSession->cipher->name))
						Table.SetCell("Cipher", pSession->cipher->name);

				} else
				{
					Table.SetCell("Status", "Waiting");
					Table.SetCell("Port", CString(pSock->GetLocalPort()));
				}
			}
			if (Table.size())
			{
				unsigned int uTableIdx = 0;
				CString sLine;
				while (Table.GetLine(uTableIdx++, sLine))
					PutModule(sLine);
			} else
				PutModule("No SDCCs currently in session");

		} else if (sCom.CaseCmp("close") == 0)
		{
			CString sName = "SCHAT::" + m_pUser->GetUserName();
			for (u_int a = 0; a < m_pManager->size(); a++)
			{
				if ((*m_pManager)[a]->GetSockName() != sName)
					continue;

				CSChatSock *pSock = (CSChatSock *)(*m_pManager)[a];
				if (sArgs.CaseCmp("(s)", 3) != 0)
					sArgs = "(s)" + sArgs;

				if (sArgs.CaseCmp(pSock->GetChatNick()) == 0)
				{
					pSock->Close();
					return;
				}
			}
			PutModule("No Such Chat [" + sArgs + "]");
		} else if (sCom.CaseCmp("showsocks") == 0)
		{
			CTable Table;
			Table.AddColumn("SockName");
			Table.AddColumn("Created");
			Table.AddColumn("LocalIP:Port");
			Table.AddColumn("RemoteIP:Port");
			Table.AddColumn("Type");
			Table.AddColumn("Cipher");
			for (u_int a = 0; a < m_pManager->size(); a++)
			{
				Table.AddRow();
				Csock *pSock = (*m_pManager)[a];
				Table.SetCell("SockName", pSock->GetSockName());
				unsigned long long iStartTime = pSock->GetStartTime();
				time_t iTime = iStartTime / 1000;
				char *pTime = ctime(&iTime);
				if (pTime)
				{
					CString sTime = pTime;
					sTime.Trim();
					Table.SetCell("Created", sTime);
				}

				if (pSock->GetType() != Csock::LISTENER)
				{
					if (pSock->GetType() == Csock::OUTBOUND)
						Table.SetCell("Type", "Outbound");
					else
						Table.SetCell("Type", "Inbound");
					Table.SetCell("LocalIP:Port", pSock->GetLocalIP() + ":" +
							CString(pSock->GetLocalPort()));
					Table.SetCell("RemoteIP:Port", pSock->GetRemoteIP() + ":" +
							CString(pSock->GetRemotePort()));
					SSL_SESSION *pSession = pSock->GetSSLSession();
					if ((pSession) && (pSession->cipher) && (pSession->cipher->name))
						Table.SetCell("Cipher", pSession->cipher->name);
					else
						Table.SetCell("Cipher", "None");

				} else
				{
					Table.SetCell("Type", "Listener");
					Table.SetCell("LocalIP:Port", pSock->GetLocalIP() +
							":" + CString(pSock->GetLocalPort()));
					Table.SetCell("RemoteIP:Port", "0.0.0.0:0");
				}
			}
			if (Table.size())
			{
				unsigned int uTableIdx = 0;
				CString sLine;
				while (Table.GetLine(uTableIdx++, sLine))
					PutModule(sLine);
			} else
				PutModule("Error Finding Sockets");

		} else if (sCom.CaseCmp("help") == 0)
		{
			PutModule("Commands are: ");
			PutModule("    help           - This text.");
			PutModule("    chat <nick>    - Chat a nick.");
			PutModule("    list           - List current chats.");
			PutModule("    close <nick>   - Close a chat to a nick.");
			PutModule("    timers         - Shows related timers.");
			PutModule("    showsocks      - Shows all socket connections.");
		} else if (sCom.CaseCmp("timers") == 0)
			ListTimers();
		else
			PutModule("Unknown command [" + sCom + "] [" + sArgs + "]");
	}

	virtual EModRet OnPrivCTCP(CNick& Nick, CString& sMessage)
	{
		if (sMessage.CaseCmp("DCC SCHAT ", 10) == 0)
		{
			// chat ip port
			unsigned long iIP = sMessage.Token(3).ToULong();
			unsigned short iPort = sMessage.Token(4).ToUShort();

			if ((iIP > 0) && (iPort > 0))
			{
				pair<u_long, u_short> pTmp;
				CString sMask;

				pTmp.first = iIP;
				pTmp.second = iPort;
				sMask = "(s)" + Nick.GetNick() + "!" + "(s)" +
					Nick.GetNick() + "@" + CUtils::GetIP(iIP);

				m_siiWaitingChats["(s)" + Nick.GetNick()] = pTmp;
				SendToUser(sMask, "*** Incoming DCC SCHAT, Accept ? (yes/no)");
				CRemMarkerJob *p = new CRemMarkerJob(this, 60, 1,
						"Remove (s)" + Nick.GetNick(),
						"Removes this nicks entry for waiting DCC.");
				p->SetNick("(s)" + Nick.GetNick());
				AddTimer(p);
				return(HALT);
			}
		}

		return(CONTINUE);
	}

	void AcceptSDCC(const CString & sNick, u_long iIP, u_short iPort)
	{
		CSChatSock *p = new CSChatSock(CUtils::GetIP(iIP), iPort, 60);
		p->SetModule(this);
		p->SetChatNick(sNick);
		CString sSockName = "SCHAT::" + m_pUser->GetUserName() +  "::" + sNick;
		m_pManager->Connect(CUtils::GetIP(iIP), iPort, sSockName, 60, true, m_pUser->GetLocalIP(), p);
		RemTimer("Remove " + sNick); // delete any associated timer to this nick
	}
	virtual EModRet OnUserMsg(CString& sTarget, CString& sMessage)
	{
		if (sTarget.Left(3) == "(s)")
		{
			CString sSockName = "SCHAT::" + m_pUser->GetUserName() + "::" + sTarget;
			CSChatSock *p = (CSChatSock *)m_pManager->FindSockByName(sSockName);
			if (!p)
			{
				map< CString,pair< u_long,u_short > >::iterator it;
				it = m_siiWaitingChats.find(sTarget);

				if (it != m_siiWaitingChats.end())
				{
					if (sMessage.CaseCmp("yes") != 0)
						SendToUser(sTarget + "!" + sTarget + "@" +
								CUtils::GetIP(it->second.first),
								"Refusing to accept DCC SCHAT!");
					else
						AcceptSDCC(sTarget, it->second.first, it->second.second);

					m_siiWaitingChats.erase(it);
					return(HALT);
				}
				PutModule("No such SCHAT to [" + sTarget + "]");
			} else
				p->Write(sMessage + "\n");

			return(HALT);
		}
		return(CONTINUE);
	}

	virtual void RemoveMarker(const CString & sNick)
	{
		map< CString,pair< u_long,u_short > >::iterator it = m_siiWaitingChats.find(sNick);
		if (it != m_siiWaitingChats.end())
			m_siiWaitingChats.erase(it);
	}

	void SendToUser(const CString & sFrom, const CString & sText)
	{
		//:*schat!znc@znc.com PRIVMSG Jim :
		CString sSend = ":" + sFrom + " PRIVMSG " + m_pUser->GetCurNick() + " :" + sText;
		PutUser(sSend);
	}

	bool IsAttached()
	{
		return(m_pUser->IsUserAttached());
	}

private:
	map< CString,pair< u_long,u_short > >		m_siiWaitingChats;
	CString		m_sPemFile;
};


//////////////////// methods ////////////////

void CSChatSock::ReadLine(const CS_STRING & sLine)
{
	if (m_pModule)
	{
		CString sText = sLine;
		if (sText[sText.length()-1] == '\n')
			sText.erase(sText.length()-1, 1);

		if (sText[sText.length()-1] == '\r')
			sText.erase(sText.length()-1, 1);

		if (m_pModule->IsAttached())
			m_pModule->SendToUser(m_sChatNick + "!" + m_sChatNick + "@" + GetRemoteIP(), sText);
		else
			AddLine(sText);
	}
}

void CSChatSock::Disconnected()
{
	if (m_pModule)
		m_pModule->SendToUser(m_sChatNick + "!" + m_sChatNick + "@" + GetRemoteIP(),
				"*** Disconnected.");
}

void CSChatSock::Connected()
{
	SetTimeout(0);
	if (m_pModule)
		m_pModule->SendToUser(m_sChatNick + "!" + m_sChatNick + "@" + GetRemoteIP(), "*** Connected.");
}

void CSChatSock::Timeout()
{
	if (m_pModule)
	{
		if (GetType() == LISTENER)
			m_pModule->PutModule("Timeout while waiting for [" + m_sChatNick + "]");
		else
			m_pModule->SendToUser(m_sChatNick + "!" + m_sChatNick + "@" + GetRemoteIP(),
					"*** Connection Timed out.");
	}
}

void CRemMarkerJob::RunJob()
{
	CSChat *p = (CSChat *)m_pModule;
	p->RemoveMarker(m_sNick);

	// store buffer
}
MODULEDEFS(CSChat, "Secure cross platform (:P) chat system")