//
// Transport.cc
//
// Transport: A virtual transport interface class for accessing
//            remote documents. Used to grab URLs based on the 
//            scheme (e.g. http://, ftp://...)
//
// Keep constructor and destructor in a file of its own.
// Also takes care of the lower-level connection code.
//
// Part of the ht://Dig package   <http://www.htdig.org/>
// Copyright (c) 1995-2004 The ht://Dig Group
// For copyright details, see the file COPYING in your distribution
// or the GNU Library General Public License (LGPL) version 2 or later 
// <http://www.gnu.org/copyleft/lgpl.html>
//
// $Id: Transport.cc,v 1.12 2004/05/28 13:15:23 lha Exp $
//
//

#ifdef HAVE_CONFIG_H
#include "htconfig.h"
#endif /* HAVE_CONFIG_H */

#include "Transport.h"

#ifdef HAVE_STD
#include <iomanip>
#ifdef HAVE_NAMESPACES
using namespace std;
#endif
#else
#include <iomanip.h>
#endif /* HAVE_STD */

#include <ctype.h>

#define DEFAULT_CONNECTION_TIMEOUT 15

///////
   //    Static variables initialization
///////

   // Debug level
   	 int Transport::debug = 0;

   // Default parser content-type string
      	 String Transport::_default_parser_content_type = 0;
	 
   // Statistics
   	 int Transport::_tot_open = 0;
   	 int Transport::_tot_close = 0;
   	 int Transport::_tot_changes = 0;


///////
   //    Transport_Response class definition
///////

 ///////
    //    Class Constructor
 ///////

Transport_Response::Transport_Response()
{

   // Initialize the pointers to the HtDateTime objs
   _modification_time = 0;
   _access_time = 0;

   // Set the content length and the return status code to negative values
   _content_length = -1;
   _status_code = -1;
   
   // Also set the document length, but to zero instead of -1
   _document_length = 0;

   // Zeroes the contents and the content-type
   _contents = 0;
   _content_type = 0;
   
   // Initialize the reason_phrase
   _reason_phrase = 0;

   // Initialize the location
   _location = 0;

}


 ///////
    //    Empty destructor
 ///////

Transport_Response::~Transport_Response()
{

   // Free memory correctly
   
   if(_modification_time)
   {
   	 delete _modification_time;
      _modification_time=0;
   }

   if(_access_time)
   {
   	 delete _access_time;
      _access_time=0;
   }

}



void Transport_Response::Reset()
{
   // Reset all the field of the object

   // Check if an HtDateTime object exists, and delete it
   if(_modification_time)
   {
   	 delete _modification_time;
      _modification_time=0;
   }

   if(_access_time)
   {
   	 delete _access_time;
      _access_time=0;
   }

   // Set the content length to a negative value
   _content_length=-1;
   
   // Also set the document length, but to zero instead of -1
   _document_length=0;

   // Zeroes the contents and content type strings
   _contents.trunc();
   _content_type.trunc();

   // Set the return status code to a negative value
   _status_code=-1;

   // Zeroes the reason phrase of the s.c.
   _reason_phrase.trunc();

   // Reset the location
   _location.trunc();
      
}



///////
   //    Transport class definition
///////

 ///////
    //    Constructor
 ///////

Transport::Transport(Connection* connection)
: _connection(connection),
   _host(0), _ip_address(0), _port(-1), _timeout(DEFAULT_CONNECTION_TIMEOUT),
   _retries(1), _wait_time(5),
   _modification_time(0), _max_document_size(0),
   _credentials(0), _useproxy(0), _proxy_credentials(0)
{
}


 ///////
    //    Destructor
 ///////

Transport::~Transport()
{

   // Close the connection that was still up
   if (CloseConnection())
      if ( debug > 4 )
         cout  << setw(5) << GetTotOpen() << " - "
            << "Closing previous connection with the remote host" << endl;

   if (_connection)
      delete (_connection);

}

///////
   //    Show the statistics
///////

ostream &Transport::ShowStatistics (ostream &out)
{
   out << " Connections opened        : " << GetTotOpen() << endl;
   out << " Connections closed        : " << GetTotClose() << endl;
   out << " Changes of server         : " << GetTotServerChanges() << endl;
         
   return out;

}


 ///////
    //    Connection Management
 ///////

   // Open the connection
   // Returns
   // 	 -      0 if failed
   // 	 -     -1 if already open
   // 	 -      1 if ok

int Transport::OpenConnection()
{
   if (!_connection) return 0;

   if(_connection->IsOpen() && _connection->IsConnected())
      return -1; // Already open and connection is up

   // No open connection
   // Let's open a new one
   
   if(_connection->Open() == NOTOK) return 0; // failed

   _tot_open ++;
   return 1;
}


   // Assign the server to the connection

int Transport::AssignConnectionServer()
{
   if (debug > 5)
      cout << "\tAssigning the server (" << _host << ") to the TCP connection" << endl;

   if( _connection == 0 )
     {
       cout << "Transport::AssignConnectionServer: _connection is NULL\n";
       exit(0);
     }
      
   if (_connection->Assign_Server(_host) == NOTOK) return 0;

   _ip_address = _connection->Get_Server_IPAddress();
   
   return 1;
}


   // Assign the remote server port to the connection

int Transport::AssignConnectionPort()
{
   if (debug > 5)
      cout << "\tAssigning the port (" << _port << ") to the TCP connection" << endl;
      
   if( _connection == 0 )
     {
       cout << "Transport::AssignConnectionPort: _connection is NULL\n";
       exit(0);
     }
      
   if (_connection->Assign_Port(_port) == NOTOK) return 0;
   
   return 1;
}




   // Connect
   // Returns
   // 	 -      0 if failed
   // 	 -     -1 if already connected
   // 	 -      1 if ok

int Transport::Connect()
{
   if (debug > 5)
      cout << "\tConnecting via TCP to (" << _host << ":" << _port << ")" << endl;

   if (isConnected()) return -1; // Already connected

   if( _connection == 0 )
     {
       cout << "Transport::Connection: _connection is NULL\n";
       exit(0);
     }

   if ( _connection->Connect() == NOTOK) return 0;  // Connection failed
   
   return 1;	// Connected
}


   // Flush the connection
   
void Transport::FlushConnection()
{
      
  if(_connection)
    {
      _connection->Flush();
    }
  
}


   // Close the connection
   // Returns
   // 	 -      0 if not open
   // 	 -      1 if closed ok


int Transport::CloseConnection()
{
   if( _connection == 0 )
   {
      // We can't treat this as a fatal error, because CloseConnection()
      // may be called from our destructor after _connection already deleted.
      // cout << "Transport::CloseConnection: _connection is NULL\n";
      // exit(0);
      return 0;
   }

   if(_connection->IsOpen())
   	 _connection->Close(); 	// Close the connection
   else return 0;

   _tot_close ++;
   
   return 1;
}


void Transport::SetConnection (const String &host, int port)
{

   if (_port != -1)
   {
      // Already initialized
      // Let's check if the server or the port are changed
      
      bool ischanged = false;

      // Checking the connection server   
      if(_host != host)   	 // server is gonna change
        ischanged=true;

      // Checking the connection port
      if( _port != port )  	 // the port is gonna change
        ischanged=true;

      if (ischanged)
      {
        // Let's close any pendant connection with the old
        // server / port pair

         _tot_changes ++;
      
         if ( debug > 4 )
            cout  << setw(5) << GetTotOpen() << " - "
               << "Change of server. Previous connection closed." << endl;
      
        CloseConnection();
      }
   }

   // Copy the host and port information to the object
   _host = host;
   _port = port;

}


// Create a new date time object containing the date specified in a string
HtDateTime *Transport::NewDate(const char *datestring)
{

   while(isspace(*datestring)) datestring++; // skip initial spaces

   DateFormat df = RecognizeDateFormat (datestring);

   if(df == DateFormat_NotRecognized)
   {
   	 // Not recognized
	 if(debug > 0)
   	 	 cout << "Date Format not recognized: " << datestring << endl;
	 
	 return 0;
   }

   HtDateTime *dt = new HtDateTime;
   
   dt->ToGMTime(); // Set to GM time
   
   switch(df)
   {
	       // Asc Time format
   	 case DateFormat_AscTime:
   	       	dt->SetAscTime((char *)datestring);
   	 	       break;
	       // RFC 1123
   	 case DateFormat_RFC1123:
   	       	dt->SetRFC1123((char *)datestring);
   	 	       break;
		  // RFC 850
   	 case DateFormat_RFC850:
   	       	dt->SetRFC850((char *)datestring);
   	 	       break;
         default:
	        cout << "Date Format not handled: " << (int)df << endl;
	        break;
   }

   return dt;
   
}


// Recognize the possible date format sent by the server
Transport::DateFormat Transport::RecognizeDateFormat (const char *datestring)
{
   register const char *s;
   
   if((s=strchr(datestring, ',')))
   {
   	 // A comma is present.
	 // Two chances: RFC1123 or RFC850

   	 if(strchr(s, '-'))
	    return DateFormat_RFC850;  // RFC 850 recognized   
	 else
	    return DateFormat_RFC1123; // RFC 1123 recognized
   }
   else
   {
      // No comma present
	 
	 // Let's try C Asctime:    Sun Nov  6 08:49:37 1994
	 if(strlen(datestring) == 24) return DateFormat_AscTime;
   }
   
   return DateFormat_NotRecognized;
   
}


// This method is used to write into 'dest' the credentials contained in 's'
// according to the HTTP Basic access authorization [RFC2617]
// It is written in this abstract class because it is used also
// when dealing with HTTP proxies, no matter what protocol we are
// using (HTTP now, but FTP in the future).

void Transport::SetHTTPBasicAccessAuthorizationString(String &dest, const String& s)
{
    static char	tbl[64] =
    {
	'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H',
	'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P',
	'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X',
	'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f',
	'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',
	'o', 'p', 'q', 'r', 's', 't', 'u', 'v',
	'w', 'x', 'y', 'z', '0', '1', '2', '3',
	'4', '5', '6', '7', '8', '9', '+', '/'
    };
    dest.trunc();
    const char	*p;
    int		n = s.length();
    int		ch;

    for (p = s.get(); n > 2; n -= 3, p += 3)
    {
	ch = *p >> 2;
	dest << tbl[ch & 077];
	ch = ((*p << 4) & 060) | ((p[1] >> 4) & 017);
	dest << tbl[ch & 077];
	ch = ((p[1] << 2) & 074) | ((p[2] >> 6) & 03);
	dest << tbl[ch & 077];
	ch = p[2] & 077;
	dest << tbl[ch & 077];
    }

    if (n != 0)
    {
	char c1 = *p;
	char c2 = n == 1 ? 0 : p[1];

	ch = c1 >> 2;
	dest << tbl[ch & 077];

	ch = ((c1 << 4) & 060) | ((c2 >> 4) & 017);
	dest << tbl[ch & 077];

	if (n == 1)
	    dest << '=';
	else
        {
	    ch = (c2 << 2) & 074;
	    dest << tbl[ch & 077];
        }
	dest << '=';
    }
}

// End of Transport.cc (it's a virtual class anyway!)