/*
Module : POP3.CPP
Purpose: Implementation for a MFC class encapsulation of the POP3 protocol
Created: PJN / 04-05-1998
History: PJN / 27-06-1998 1) Fixed a potential buffer overflow problem in Delete
                          and Retrieve functions when a large message number was
                          specified.
                          2) Improve the ReadResponse code by a) passing the 
                          readability check onto the scoket class and b) Sleeping
                          for 100 ms prior to looping around waiting for new 
                          response data
                          3) Classes are now fully Unicode compliant. Unicode
                          build configurations are also now included.
                          4) Now supports the TOP POP3 command which can be
                          issued using the GetHeader function.

         PJN / 04-01-1999 1) Properly UNICODE enabled the code

         PJN / 22-02-1999 1) Improved the reading of responses back from the server by implementing
                          a growable receive buffer
                          2) timeout is now 60 seconds when building for debug
                          3) Code now yields its time slice while waiting for a timeout
                          4) Made most functions virtual to help end user usage

         PJN / 25-03-1999 1) Fixed memory leak in the CPop3Connection::ReadReturnResponse function.
                          2) Now sleeps for 250 ms instead of yielding the time slice. This helps 
                          reduce CPU usage when waiting for data to arrive in the socket

         PJN / 15-06-1999 1) Added functions to return the message body, header or a particular
                          header field of a message
                          2) Tidied up some of the TRACE messages which the code generates

         PJN / 16-06-1999 1) Fixed a bug in the GetHeaderItem function which was causing a header
                          item which appeared at the begining of the header fields to fail to be 
                          parsed incorrectly.

         PJN / 27-06-1999 1) Fixed a bug in the GetHeaderItem function when a header spanned 
                          multiple lines as is allowed by RFC 822

         PJN / 29-06-1999 1) Another improvement to GetHeaderItem. When will it end <g>. Originally 
                          this was reported as a bug but upon further investigation it turns out that
                          the message which was causing the problems had embedded tabs in the header. 
                          This is discouraged by the RFC which refers to mail headers (RFC 822). 
                          The code has been enhanced to handle this case. Thanks to Chris Bishop 
                          for spotting this.
                          2) Fix for a bug in GetHeaderItem where I accidently was using "=" instead of
                          "==". Thanks to Angelini Fabio for spotting this.

         PJN / 05-07-1999 1) Addition of the following functions:

                          i)   CPop3Message::GetReplyTo
                          ii)  CPop3Message::GetRawBody      
                          iii) CPop3Message::GetSubject                 
	                        iv)  CPop3Message::GetFrom                    
	                        v)   CPop3Message::GetDate                    

                          2) GetHeaderItem function now uses case insensitive searching
                          3) GetHeaderItem now allows you to search for the "n'th" header of a specified type

         PJN / 24-08-99   1) Fixed a bug whereby the function GetHeader was sometimes failing when it
                          was called when the message was retrieved using the "TOP" command.
                             

Copyright (c) 1998 - 1999 by PJ Naughter.  
All rights reserved.

*/

//////////////// Includes ////////////////////////////////////////////
#include "stdafx.h"
#include <afxpriv.h>
#include "pop3.h"



//////////////// Macros //////////////////////////////////////////////
#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif



//////////////// Implementation //////////////////////////////////////
CPop3Message::CPop3Message()
{
  m_pszMessage = NULL;
}

CPop3Message::~CPop3Message()
{
  if (m_pszMessage)
  {
    delete[] m_pszMessage;
	m_pszMessage = NULL;
  }
}

CString CPop3Message::GetHeaderItem(const CString& sName, int nItem) const
{
  //Value which will be returned by this function
  CString sField;

  //Get the message header (add an extra "\r\n" at the
  //begining to aid in the parsing)  
	CString sHeader(_T("\r\n"));
  sHeader += GetHeader();
  CString sUpCaseHeader(sHeader);
  sUpCaseHeader.MakeUpper();

  CString sUpCaseName(sName);
  sUpCaseName.MakeUpper();

  //Find the specified line in the header
  CString sFind(CString(_T("\r\n")) + sUpCaseName + _T(":"));
  int nFindLength = sFind.GetLength();
  int nFindStart = sUpCaseHeader.Find(sFind);
  int nFind = nFindStart;
	for (int i=0; i<nItem; i++) 
  {
    //Get ready for the next loop around
    sUpCaseHeader = sUpCaseHeader.Right(sUpCaseHeader.GetLength() - nFind - nFindLength);
    nFind = sUpCaseHeader.Find(sFind);
    
		if (nFind == -1)
			return _T(""); //Not found
    else
      nFindStart += (nFind + nFindLength);
	}

  if (nFindStart != -1)
    nFindStart += (3 + sName.GetLength());
  if (nFindStart != -1)
  {
    BOOL bFoundEnd = FALSE;
    int i = nFindStart;
    int nLength = sHeader.GetLength();
    do
    {
      //Examine the current 3 characters
      TCHAR c1 = _T('\0');
      if (i < nLength)
        c1 = sHeader[i];
      TCHAR c2 = _T('\0');
      if (i < (nLength-1))
        c2 = sHeader[i+1];
      TCHAR c3 = _T('\0');
      if (i < (nLength-2))
        c3 = sHeader[i+2];

      //Have we found the terminator
      if ((c1 == _T('\0')) ||
          ((c1 == _T('\r')) && (c2 == _T('\n')) && (c3 != _T(' ')) && c3 != _T('\t')))
      {
        bFoundEnd = TRUE;
      }
      else
      {
        //Move onto the next character  
        ++i;
      }
    }
    while (!bFoundEnd);
    sField = sHeader.Mid(nFindStart, i - nFindStart);

    //Remove any embedded "\r\n" sequences from the field
    int nEOL = sField.Find(_T("\r\n"));
    while (nEOL != -1)
    {
      sField = sField.Left(nEOL) + sField.Right(sField.GetLength() - nEOL - 2);
      nEOL = sField.Find(_T("\r\n"));
    }

    //Replace any embedded "\t" sequences with spaces
    int nTab = sField.Find(_T('\t'));
    while (nTab != -1)
    {
      sField = sField.Left(nTab) + _T(' ') + sField.Right(sField.GetLength() - nTab - 1);
      nTab = sField.Find(_T('\t'));
    }

    //Remove any leading or trailing white space from the Field Body
    sField.TrimLeft();
    sField.TrimRight();
  }

	return sField;
}

CString CPop3Message::GetHeader() const
{
  //Value which will be returned by this function
  CString sHeader;

  //Find the divider between the header and body
	CString sMessage(m_pszMessage);
  int nFind = sMessage.Find(_T("\r\n\r\n"));
  if (nFind != -1)
    sHeader = sMessage.Left(nFind);
  else
  {
    //No divider, then assume all the text is the header
    sHeader = sMessage;
  }

  return sHeader;
}

LPCSTR CPop3Message::GetRawBody() const
{
	char* pszStartBody = strstr(GetMessageText(), "\r\n\r\n");
	if (pszStartBody == NULL) 
    return NULL;
	else 
    return pszStartBody + 4;
}

CString CPop3Message::GetBody() const
{
  CString sBody;
  LPCSTR pszBody = GetRawBody();
  if (pszBody)
    sBody = pszBody;
  return sBody;
}

CString CPop3Message::GetReplyTo() const
{
	CString sRet = GetHeaderItem("Reply-To");
  if (sRet.IsEmpty())
  {
    sRet = GetFrom();
    if (sRet.IsEmpty())
    {
      sRet = GetHeaderItem(_T("Sender"));
      if (sRet.IsEmpty())
        sRet = GetHeaderItem(_T("Return-Path"));
    }
  }
	return sRet;
}

CPop3Socket::CPop3Socket()
{
  m_hSocket = INVALID_SOCKET; //default to an invalid scoket descriptor
}

CPop3Socket::~CPop3Socket()
{
  Close();
}

BOOL CPop3Socket::Create()
{
  m_hSocket = socket(AF_INET, SOCK_STREAM, 0);
  return (m_hSocket != INVALID_SOCKET);
}

BOOL CPop3Socket::Connect(LPCTSTR pszHostAddress, int nPort)
{
	//For correct operation of the T2A macro, see MFC Tech Note 59
	USES_CONVERSION;

  //must have been created first
  ASSERT(m_hSocket != INVALID_SOCKET);
  
	//Determine if the address is in dotted notation
	SOCKADDR_IN sockAddr;
	ZeroMemory(&sockAddr, sizeof(sockAddr));
	sockAddr.sin_family = AF_INET;
	sockAddr.sin_port = htons((u_short)nPort);
  char* pszAsciiHostAddress = T2A((LPTSTR) pszHostAddress);
	sockAddr.sin_addr.s_addr = inet_addr(pszAsciiHostAddress);

	//If the address is not dotted notation, then do a DNS 
	//lookup of it.
	if (sockAddr.sin_addr.s_addr == INADDR_NONE)
	{
		LPHOSTENT lphost;
		lphost = gethostbyname(pszAsciiHostAddress);
		if (lphost != NULL)
			sockAddr.sin_addr.s_addr = ((LPIN_ADDR)lphost->h_addr)->s_addr;
		else
		{
			WSASetLastError(WSAEINVAL); 
			return FALSE;
		}
	}

	//Call the protected version which takes an address 
	//in the form of a standard C style struct.
	return Connect((SOCKADDR*)&sockAddr, sizeof(sockAddr));
}

BOOL CPop3Socket::Connect(const SOCKADDR* lpSockAddr, int nSockAddrLen)
{
	return (connect(m_hSocket, lpSockAddr, nSockAddrLen) != SOCKET_ERROR);
}

BOOL CPop3Socket::Send(LPCSTR pszBuf, int nBuf)
{
  //must have been created first
  ASSERT(m_hSocket != INVALID_SOCKET);

  return (send(m_hSocket, pszBuf, nBuf, 0) != SOCKET_ERROR);
}

int CPop3Socket::Receive(LPSTR pszBuf, int nBuf)
{
  //must have been created first
  ASSERT(m_hSocket != INVALID_SOCKET);

  return recv(m_hSocket, pszBuf, nBuf, 0); 
}

void CPop3Socket::Close()
{
	if (m_hSocket != INVALID_SOCKET)
	{
		VERIFY(SOCKET_ERROR != closesocket(m_hSocket));
		m_hSocket = INVALID_SOCKET;
	}
}

BOOL CPop3Socket::IsReadible(BOOL& bReadible)
{
  timeval timeout = {0, 0};
  fd_set fds;
  FD_ZERO(&fds);
  FD_SET(m_hSocket, &fds);
  int nStatus = select(0, &fds, NULL, NULL, &timeout);
  if (nStatus == SOCKET_ERROR)
  {
    return FALSE;
  }
  else
  {
    bReadible = !(nStatus == 0);
    return TRUE;
  }
}






CPop3Connection::CPop3Connection()
{
  m_nNumberOfMails = 0;
  m_bListRetrieved = FALSE;
  m_bStatRetrieved = FALSE;
  m_bUIDLRetrieved = FALSE;
  m_msgSizes.RemoveAll();
  m_bConnected = FALSE;
#ifdef _DEBUG
  m_dwTimeout = 60000; //default timeout of 60 seconds when debugging
#else
  m_dwTimeout = 2000;  //default timeout of 2 seconds for normal release code
#endif
}

CPop3Connection::~CPop3Connection()
{
  if (m_bConnected)
    Disconnect();
}

BOOL CPop3Connection::Connect(LPCTSTR pszHostName, LPCTSTR pszUser, LPCTSTR pszPassword, int nPort)
{
	//For correct operation of the T2A macro, see MFC Tech Note 59
	USES_CONVERSION;

  //Create the socket
  if (!m_Pop.Create())
  {
    TRACE(_T("Failed to create client socket, GetLastError:%d\n"), GetLastError());
    return FALSE;
  }

  //Connect to the POP3 Host
  if (!m_Pop.Connect(pszHostName, nPort))
  {
    TRACE(_T("Could not connect to the POP3 mailbox, GetLastError:%d\n"), GetLastError());
    return FALSE;
  }
  else
  {
    //We're now connected !!
    m_bConnected = TRUE;

    //check the response
    if (!ReadCommandResponse())
    {
      TRACE(_T("Failed while connected to read a command response from the POP3 server\n"));
      Disconnect();
      return FALSE;
    }

    //Send the POP3 username and check the response
    char sBuf[128];
    char* pszAsciiUser = T2A((LPTSTR) pszUser);
    ASSERT(strlen(pszAsciiUser) < 100); 
    sprintf(sBuf, "USER %s\r\n", pszAsciiUser);
    int nCmdLength = strlen(sBuf);
    if (!m_Pop.Send(sBuf, nCmdLength))
    {
      TRACE(_T("Failed to send the USER command to the POP3 server\n"));
      Disconnect();
      return FALSE;
    }
    if (!ReadCommandResponse())
    {
      TRACE(_T("Failed while connected to read a USER command response from the POP3 server\n"));
      Disconnect();
      return FALSE;
    } 

    //Send the POP3 password and check the response
    char* pszAsciiPassword = T2A((LPTSTR) pszPassword);
    ASSERT(strlen(pszAsciiPassword) < 100);
    sprintf(sBuf, "PASS %s\r\n", pszAsciiPassword);
    nCmdLength = strlen(sBuf);
    if (!m_Pop.Send(sBuf, nCmdLength))
    {
      TRACE(_T("Failed to send the PASS command to the POP3 server\n"));
      Disconnect();
      return FALSE;
    }
    if (!ReadCommandResponse())
    {
      TRACE(_T("Failed while connected to read a PASS command response from the POP3 server\n"));
      Disconnect();
      return FALSE;
    }
    
    return TRUE;
  }
}

BOOL CPop3Connection::Disconnect()
{          
  BOOL bSuccess = FALSE;      

  //disconnect from the POP3 server if connected 
  if (m_bConnected)
  {
    char sBuf[10];
    strcpy(sBuf, "QUIT\r\n");
    int nCmdLength = strlen(sBuf);
    if (!m_Pop.Send(sBuf, nCmdLength))
      TRACE(_T("Failed to send the QUIT command to the POP3 server\n"));

    //Check the reponse
    bSuccess = ReadCommandResponse();

    //Reset all the state variables
    m_bConnected = FALSE;
    m_bListRetrieved = FALSE;
    m_bStatRetrieved = FALSE;
    m_bUIDLRetrieved = FALSE;
  }
  else
    TRACE(_T("CPop3Connection, Already disconnected\n"));
 
  //free up our socket
  m_Pop.Close();
 
  return bSuccess;
}

BOOL CPop3Connection::Delete(int nMsg)
{
  //Must be connected to perform a delete
  ASSERT(m_bConnected);

  //if we haven't executed the LIST command then do it now
  if (!m_bListRetrieved)
    List();

  //Send the DELE command along with the message ID
	char sBuf[20];
 	sprintf(sBuf, "DELE %d\r\n", nMsg);
  int nCmdLength = strlen(sBuf);
	if (!m_Pop.Send(sBuf, nCmdLength))
  {
    TRACE(_T("Failed to send the DELE command to the POP3 server\n"));
    return FALSE;
  }

	return ReadCommandResponse();
}

BOOL CPop3Connection::Statistics(int& nNumberOfMails, int& nTotalMailSize)
{
  //Must be connected to perform a "STAT"
  ASSERT(m_bConnected);

  //Send the STAT command
	char sBuf[10];
 	strcpy(sBuf, "STAT\r\n");
  int nCmdLength = strlen(sBuf);
	if (!m_Pop.Send(sBuf, nCmdLength))
  {
    TRACE(_T("Failed to send the STAT command to the POP3 server\n"));
    return FALSE;
  }

	return ReadStatResponse(nNumberOfMails, nTotalMailSize);
}

BOOL CPop3Connection::GetMessageSize(int nMsg, DWORD& dwSize)
{
  BOOL bSuccess = TRUE;

  //if we haven't executed the LIST command then do it now
  if (!m_bListRetrieved)
    bSuccess = List();

  //nMsg must be in the correct range
  ASSERT((nMsg > 0) && (nMsg <= m_msgSizes.GetSize()));

  //retrieve the size from the message size array
  dwSize = m_msgSizes.GetAt(nMsg - 1);

  return bSuccess;
}

BOOL CPop3Connection::GetMessageID(int nMsg, CString& sID)
{
  BOOL bSuccess = TRUE;

  //if we haven't executed the UIDL command then do it now
  if (!m_bUIDLRetrieved)
    bSuccess = UIDL();

  //nMsg must be in the correct range
  ASSERT((nMsg > 0) && (nMsg <= m_msgIDs.GetSize()));

  //retrieve the size from the message size array
  sID = m_msgIDs.GetAt(nMsg - 1);

  return bSuccess;
}

BOOL CPop3Connection::List()
{