/*
 * This file is a part of CMSLU -- Content Management System like Unix
 * and is not publicly distributed
 * 
 * Copyright (c) 2008-2009, Tomasz Sowa
 * All rights reserved.
 * 
 */
 
#include <sys/stat.h>
#include "sessionmanager.h"
#include "request.h"
#include "log.h"
#include "data.h"
#include "session.h"
#include "sessionparser.h"


SessionManager::SessionManager()
{
	session_checker = 0;
}


bool SessionManager::IsSession(long id)
{
	if( session_table.FindById(id) == session_table.End() )
		return false;

return true;
}


long SessionManager::CreateSessionId()
{
long id;
	
	// make sure to call std::srand() somewhere at the beginning
	// id must be != 0 (0 is reserved)
	do
	{
		if( sizeof(long) == 8 )
		{
			id = ((unsigned long)std::rand()) << 32 + std::rand();
		}
		else
		{
			id = std::rand();
		}
		
		id += std::time(0);
		
		if( id < 0 )
			id = -id;
		
	}
	while( id == 0 ); // 0 reserved for a temporary session

	
return id;
}


void SessionManager::CreateTemporarySession()
{
	SessionContainer::Iterator i = session_table.FindById( 0 );
	
	if( i == session_table.End() )
	{
		Session s;
		s.id = 0;
		
		session_table.PushBack(s);
		request.session = &session_table.Back();
	}
	else
	{
		request.session = &(*i);
	}
}


void SessionManager::CreateSession()
{
Session s;
int attempts = 100;

	for( ; attempts > 0 ; --attempts )
	{
		s.id = CreateSessionId();
	
		bool added = session_table.PushBack(s);	

		if( added )
		{
			request.session = &session_table.Back();
			request.session->new_session = true;
			
			log << log2 << "SM: created a new session: " << request.session->id << logend;
				
		return;
		}
	}
	
	// there is a problem with generating a new session id
	// we do not set a session cookie
	CreateTemporarySession();
	log << log1 << "SM: cannot create a session id (temporary used: with id 0)" << logend;
}



void SessionManager::SetSession()
{
	CookieTable::iterator i = request.cookie_table.find(data.http_session_id_name);

	if( i == request.cookie_table.end() )
	{
		CreateSession();
	}
	else
	{
		long id = atol(i->second.c_str());
		SessionContainer::Iterator s = session_table.FindById(id);
	
		if( s != session_table.End() )
		{
			// that session is in the table
			request.session = &(*s);
			request.session->new_session = false;
			
			session_table.UpdateLastTime(s, std::time(0));
		
			log << log2 << "SM: session: " << s->id;
			
			if( request.session->puser )
				log << log2 << ", user: " << request.session->puser->name << ", id: " << request.session->puser->id;
				
			log << log2 << logend;
		}
		else
		{
			// there is no such a session
			// deleting the old cookie
			request.cookie_table.erase(i);

			// and creating a new one
			CreateSession();
		}
	}
	
	
	
	// request.session is set now
}



SessionContainer::Iterator SessionManager::SessionBegin()
{
	return session_table.Begin();
}

SessionContainer::Iterator SessionManager::SessionEnd()
{
	return session_table.End();
}




void SessionManager::DeleteOldSessions()
{
	session_table.DelFirstByTimeInterval(data.session_max_iddle);

	if( ++session_checker > 1000 )
	{
		// we make the test after 1000 requests
		log << log3 << "SM: checking sessions which have 'remember me' flag set" << logend;

		session_checker = 0;
		session_table.DelFirstByTimeInterval(data.session_remember_max_iddle, false);
	}
}


void SessionManager::LoadSessions()
{
SessionParser sp;

	sp.Parse(data.session_file, session_table);

}


void SessionManager::SaveSessions()
{
	if( data.session_file.empty() )
		return;

	std::ofstream file(data.session_file.c_str());

	if( !file )
	{
		log << log1 << "SM: cannot open the session file for writing - sessions lost" << logend;
		return;
	}

	log << log2 << "SM: saving sessions" << logend;
	long len = 0;

	SessionContainer::Iterator i = session_table.Begin();

	for( ; i!=session_table.End() ; ++i )
	{
		if( i->id != 0 && i->puser )
		{
			file << i->id << ' ' << i->puser->id << ' ' << i->remember_me << ' ';
			file << (long)i->time << ' ' << (long)i->last_time << std::endl;

			++len;
		}
	}

	file.close();
	chmod(data.session_file.c_str(), 0600);

	log << log2 << "SM: saved " << len << " session(s)" << logend;
}