//
// HtHTTP.h
//
// HtHTTP: Class for HTTP messaging (derived from Transport)
//
// Gabriele Bartolini - Prato - Italia
// started: 03.05.1999
//
// ////////////////////////////////////////////////////////////
//
// The HtHTTP class should provide (as I hope) an interface for
// retrieving document on the Web. It derives from Transport class.
//
// It should be HTTP/1.1 compatible.
//
// It also let us take advantage of persitent connections use,
// and optimize request times (specially if directed to the same
// server).
//
// HtHTTP use another class to store the response returned by the
// remote server.
//
// Now cookies management is enabled.
//
///////
//
// 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: HtHTTP.h,v 1.15 2004/05/28 13:15:23 lha Exp $ 
//

#ifndef _HTHTTP_H
#define _HTHTTP_H

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

#include "Transport.h"

// Cookie support
#include "HtCookie.h"
#include "HtCookieJar.h"

#include "URL.h"
#include "htString.h"

// for HtHTTP::ShowStatistics#ifdef HAVE_STD
#ifdef HAVE_STD
#include <iostream>
#ifdef HAVE_NAMESPACES
using namespace std;
#endif
#else
#include <iostream.h>
#endif /* HAVE_STD */

// In advance declarations

class HtHTTP;


class HtHTTP_Response : public Transport_Response
{

   friend class HtHTTP;    // declaring friendship
   
   public:
///////
   //    Construction / Destruction
///////
	 
      HtHTTP_Response();
      ~HtHTTP_Response();


///////
   //    Interface
///////

   	 // Reset
	 void Reset();
	 
	 // Get the HTTP version
   	 const String &GetVersion() const { return _version; }

	 // Get the Transfer-encoding
   	 const String &GetTransferEncoding() const
            { return _transfer_encoding; }

	 // Get server info
   	 const String &GetServer() const { return _server; }

	 // Get Connection info
   	 const String &GetConnectionInfo() const { return _hdrconnection; }

	 // Get Content language
   	 const String &GetContentLanguage() const { return _content_language; }


   protected:

   // Status line information
   
   	 String	   _version;	          // HTTP Version

   // Other header information
   
	 String    _transfer_encoding;    // Transfer-encoding
   	 String	   _server;	          // Server string returned
   	 String	   _hdrconnection;	  // Connection header
	 String    _content_language;     // Content-language

};



class HtHTTP : public Transport
{
private:
   HtHTTP() {}    // Declared private - avoids default constructor to be created
      	          // in some cases by the compiler.
public:

///////
   //    Construction/Destruction
///////

    HtHTTP(Connection&);
    virtual ~HtHTTP() = 0;

   // Information about the method to be used in the request

   enum Request_Method
   {
   	 Method_GET,
	 Method_HEAD
   };
   


///////
   //    Sends an HTTP request message
///////

   // manages a Transport request (method inherited from Transport class)
   virtual DocStatus Request ();
   
   // Sends a request message for HTTP
   virtual DocStatus HTTPRequest ();
   

///////
   //    Control of member the variables
///////

 ///////
    //    Set the Request Method
 ///////

   void SetRequestMethod (Request_Method rm) { _Method = rm; }
   Request_Method GetRequestMethod() { return _Method; }
   

 ///////
    //    Interface for resource retrieving
 ///////

   // Set and get the document to be retrieved
   void SetRequestURL(const URL &u) { _url = u;}
   URL GetRequestURL () { return _url;}


   // Set and get the referring URL
   void SetRefererURL (const URL& u) { _referer = u;}
   URL GetRefererURL () { return _referer;}

   // Set and get the accept-language string
   void SetAcceptLanguage (const String& al) { _accept_language = al; }
   URL GetAcceptLanguage () { return _accept_language; }

   // Info for multiple requests (static)
   // Get the User agent string
   static void SetRequestUserAgent (const String &s) { _user_agent=s; }
   static const String &GetRequestUserAgent() { return _user_agent; }

   // Set (Basic) Authentication Credentials
   virtual void SetCredentials (const String& s);

   // Set (Basic) Authentication Credentials for the HTTP Proxy
   virtual void SetProxyCredentials (const String& s);

 ///////
    //    Interface for the HTTP Response
 ///////

   // We have a valid response only if the status code is not equal to
   // initialization value
   
   Transport_Response *GetResponse()
   {
      if (_response._status_code != -1)
         return &_response;
      else return 0;}


   // Get the document status 
   virtual DocStatus GetDocumentStatus()
      { return GetDocumentStatus (_response); }
   
   // It's a static method
   static DocStatus GetDocumentStatus(HtHTTP_Response &);



///////
   //    Persistent connection choices interface
///////

   // Is allowed
   bool isPersistentConnectionAllowed() {return _persistent_connection_allowed;}
   
   // Is possible
   bool isPersistentConnectionPossible() {return _persistent_connection_possible;}

   // Check if a persistent connection is possible depending on the HTTP response
   void CheckPersistentConnection(HtHTTP_Response &);

   // Is Up (is both allowed and permitted by the server too)
   bool isPersistentConnectionUp()
   	    { return isConnected() && isPersistentConnectionAllowed() &&
   	       	   isPersistentConnectionPossible(); }
   
   // Allow Persistent Connection
   void AllowPersistentConnection() { _persistent_connection_allowed=true; }
   
   // Disable Persistent Connection
   void DisablePersistentConnection() { _persistent_connection_allowed=false; }
   
   // Allow Cookies
   void AllowCookies() { _send_cookies=true; }
   
   // Disable Persistent Connection
   void DisableCookies() { _send_cookies=false; }
   

///////
   // 	 Set the cookie manager class (that is to say the class)
///////

   // It's set only if not done before
   static void SetCookieJar(HtCookieJar *cj) { _cookie_jar = cj; }


///////
   // 	 Manage statistics
///////
   
   static int GetTotSeconds () { return _tot_seconds; }   

   static int GetTotRequests () { return _tot_requests; }   

   static int GetTotBytes () { return _tot_bytes; }   

   static double GetAverageRequestTime ()
   	 { return _tot_seconds?( ((double) _tot_seconds) / _tot_requests) : 0; }   

   static float GetAverageSpeed ()
   	 { return _tot_bytes?( ((double) _tot_bytes) / _tot_seconds) : 0; }   

   static void ResetStatistics ()
   	 { _tot_seconds=0; _tot_requests=0; _tot_bytes=0;}   

   // Show stats
   static ostream &ShowStatistics (ostream &out);



///////
   //    Set the _head_before_get option 
   //    make a request to be made up of a HEAD call and then,
   //    if necessary, a GET call
///////
   
   static void EnableHeadBeforeGet() { _head_before_get = true; }
   static void DisableHeadBeforeGet() { _head_before_get = false; }

   static bool HeadBeforeGet() { return _head_before_get; }


///////
   //    Set the controller for the parsing check. That is to say
   //    that External function that checks if a document is parsable or not.
   //    CanBeParsed static attribute should point to a function
   //    that returns an int value, given a char * containing the content-type.
///////

   static void SetParsingController (int (*f)(char*)) { CanBeParsed = f; }

protected:

///////
   //    Member attributes
///////

   Request_Method    _Method;
   
   ///////
      //    Http single Request information (Member attributes)
   ///////

   int      	_bytes_read;        // Bytes read
   URL		_url;               // URL to retrieve
   URL		_referer;	    // Referring URL

   String      _accept_language;    // accept-language directive
   
   ///////
      //    Http multiple Request information
   ///////

   static String   	_user_agent;  	   // User agent
   


   ///////
      //    Http Response information
   ///////

   HtHTTP_Response	 _response; 	 // Object where response
   	       	   	       	   	 // information will be stored into


   ///////
      //    Allow or not a persistent connection (user choice)
   ///////

   bool _persistent_connection_allowed;


   ///////
      //    Is a persistent connection possible (with this http server)?
   ///////

   bool _persistent_connection_possible;

   ///////
      //    Are cookies enabled?
   ///////

   bool _send_cookies;

   ///////
      //    Option that, if set to true, make a request to be made up
      //    of a HEAD call and then, if necessary, a GET call
   ///////
   
   static bool _head_before_get;

///////
   //    Manager of the body reading
///////

   int (HtHTTP::*_readbody) ();


///////
   //    Enum
///////

   // Information about the status of a connection
   
   enum ConnectionStatus
   {
   	 Connection_ok,
	 Connection_already_up,
   	 Connection_open_failed,
   	 Connection_no_server,
   	 Connection_no_port,
   	 Connection_failed
   };


///////
   //    Protected Services or method (Hidden by outside)
///////


   ///////
      //    Establish the connection
   ///////

   ConnectionStatus EstablishConnection ();
   

   ///////
      //    Set the string of the command containing the request
   ///////

   void SetRequestCommand(String &);


   ///////
      //    Parse the header returned by the server
   ///////

   int ParseHeader();

   ///////
      //    Check if a document is parsable looking the content-type info
   ///////

   static bool isParsable(const char *);

   ///////
      //    Read the body returned by the server
   ///////

   void SetBodyReadingController (int (HtHTTP::*f)()) { _readbody = f; }
   int ReadBody();
   int ReadChunkedBody();  // Read the body of a chunked encoded-response


   // Finish the request and return a DocStatus value;

   DocStatus FinishRequest (DocStatus);


///////
   //    Static attributes and methods
///////
   
   // Unique cookie Jar
   static HtCookieJar *_cookie_jar;  // Jar containing all of the cookies
      
   static int  _tot_seconds;  	 // Requests last (in seconds)
   static int  _tot_requests; 	 // Number of requests
   static int  _tot_bytes;    	 // Number of bytes read

   // This is a pointer to function that check if a ContentType
   // is parsable or less.
   
   static int (*CanBeParsed) (char *);
   
};

#endif