/*
 * Copyright (C) 2004-2011  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.
 *
 * Email Monitor / Retrieval
 * Author: imaginos <imaginos@imaginos.net>
 */

#include "FileUtils.h"
#include "MD5.h"
#include "User.h"
#include "znc.h"
#include <sstream>

using std::stringstream;

struct EmailST
{
	CString sFrom;
	CString sSubject;
	CString sUidl;
	u_int   iSize;
};

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

	virtual ~CEmailJob() {}

protected:
	virtual void RunJob();
};

class CEmail : public CModule
{
public:
	MODCONSTRUCTOR(CEmail)
	{
		m_iLastCheck = 0;
		m_bInitialized = false;
	}

	virtual ~CEmail() {}

	virtual bool OnLoad(const CString & sArgs, CString& sMessage) {
#ifndef MOD_EMAIL_ALLOW_EVERYONE
		if (!m_pUser->IsAdmin()) {
			sMessage = "You must be admin to use the email module";
			return false;
		}
#endif
		m_sMailPath = sArgs;

		StartParser();
		if (m_pUser->IsUserAttached())
			StartTimer();

		return true;
	}

	virtual void OnClientLogin()
	{
		stringstream s;
		s << "You have " << m_ssUidls.size() << " emails.";
		PutModule(s.str());
		StartTimer();
	}
	virtual void OnClientDisconnect()
	{
		RemTimer("EMAIL::" + m_pUser->GetUserName());
	}

	void StartTimer()
	{
		if (!FindTimer("EMAIL::" + m_pUser->GetUserName()))
		{
			CEmailJob *p = new CEmailJob(this, 60, 0, "EmailMonitor", "Monitors email activity");
			AddTimer(p);
		}
	}

	virtual void OnModCommand(const CString& sCommand);
	void StartParser();

	void ParseEmails(const vector<EmailST> & vEmails)
	{
		if (!m_bInitialized)
		{
			m_bInitialized = true;
			for (u_int a = 0; a < vEmails.size(); a++)
				m_ssUidls.insert(vEmails[a].sUidl);

			stringstream s;
			s << "You have " << vEmails.size() << " emails.";
			PutModule(s.str());
		} else
		{
			set<CString> ssUidls;

			CTable Table;
			Table.AddColumn("From");
			Table.AddColumn("Size");
			Table.AddColumn("Subject");

			for (u_int a = 0; a < vEmails.size(); a++)
			{
				if (m_ssUidls.find(vEmails[a].sUidl) == m_ssUidls.end())
				{
					//PutModule("------------------- New Email -------------------");
					Table.AddRow();
					Table.SetCell("From", vEmails[a].sFrom.Ellipsize(32));
					Table.SetCell("Size", CString(vEmails[a].iSize));
					Table.SetCell("Subject", vEmails[a].sSubject.Ellipsize(64));
				}
				ssUidls.insert(vEmails[a].sUidl);
			}

			m_ssUidls = ssUidls; // keep the list in synch

			if (Table.size()) {
				PutModule(Table);

				stringstream s;
				s << "You have " << vEmails.size() << " emails.";
				PutModule(s.str());
			}
		}
	}

private:
	CString      m_sMailPath;
	time_t       m_iLastCheck;
	set<CString> m_ssUidls;
	bool         m_bInitialized;
};

class CEmailFolder : public CSocket
{
public:
	CEmailFolder(CEmail *pModule, const CString & sMailbox) : CSocket(pModule)
	{
		m_pModule = pModule;
		m_sMailbox = sMailbox;
		EnableReadLine();
	}

	virtual ~CEmailFolder()
	{
		if (!m_sMailBuffer.empty())
			ProcessMail(); // get the last one

		if (!m_vEmails.empty())
			m_pModule->ParseEmails(m_vEmails);
	}

	virtual void ReadLine(const CS_STRING & sLine)
	{
		if (sLine.Left(5) == "From ")
		{
			if (!m_sMailBuffer.empty())
			{
				ProcessMail();
				m_sMailBuffer.clear();
			}
		}
		m_sMailBuffer += sLine;
	}

	void ProcessMail()
	{
		EmailST tmp;
		tmp.sUidl = (char *)CMD5(m_sMailBuffer.Left(255));
		VCString vsLines;
		VCString::iterator it;

		m_sMailBuffer.Split("\n", vsLines);

		for (it = vsLines.begin(); it != vsLines.end(); it++) {
			CString sLine(*it);
			sLine.Trim();
			if (sLine.empty())
				break; // out of the headers

			if (sLine.Equals("From: ", false, 6))
				tmp.sFrom = sLine.substr(6, CString::npos);
			else if (sLine.Equals("Subject: ", false, 9))
				tmp.sSubject = sLine.substr(9, CString::npos);

			if ((!tmp.sFrom.empty()) && (!tmp.sSubject.empty()))
				break;
		}
		tmp.iSize = m_sMailBuffer.length();
		m_vEmails.push_back(tmp);
	}
private:
	CEmail          *m_pModule;
	CString          m_sMailbox;
	CString          m_sMailBuffer;
	vector<EmailST>  m_vEmails;
};

void CEmail::OnModCommand(const CString& sCommand)
{
	CString sCom = sCommand.Token(0);

	if (sCom == "timers")
	{
		ListTimers();
	} else
		PutModule("Error, no such command [" + sCom + "]");
}

void CEmail::StartParser()
{
	CString sParserName = "EMAIL::" + m_pUser->GetUserName();

	if (m_pManager->FindSockByName(sParserName))
		return; // one at a time sucker

	CFile cFile(m_sMailPath);
	if ((!cFile.Exists()) || (cFile.GetSize() == 0))
	{
		m_bInitialized = true;
		return; // der
	}

	if (cFile.GetMTime() <= m_iLastCheck)
		return; // only check if modified

	int iFD = open(m_sMailPath.c_str(), O_RDONLY);
	if (iFD >= 0)
	{
		m_iLastCheck = time(NULL);
		CEmailFolder *p = new CEmailFolder(this, m_sMailPath);
		p->SetRSock(iFD);
		p->SetWSock(iFD);
		m_pManager->AddSock(p, "EMAIL::" + m_pUser->GetUserName());
	}
}

void CEmailJob::RunJob()
{
	CEmail *p = (CEmail *)m_pModule;
	p->StartParser();
}
MODULEDEFS(CEmail, "Monitors Email activity on local disk /var/mail/user")