/*       +------------------------------------+
 *       | Inspire Internet Relay Chat Daemon |
 *       +------------------------------------+
 *
 *  InspIRCd is copyright (C) 2002-2006 ChatSpike-Dev.
 *		       E-mail:
 *		<brain@chatspike.net>
 *	   	  <Craig@chatspike.net>
 *     
 * Written by Craig Edwards, Craig McLure, and others.
 * This program is free but copyrighted software; see
 *	    the file COPYING for details.
 *
 * ---------------------------------------------------
 */

using namespace std;
 
#include "users.h"
#include "channels.h"
#include "modules.h"
#include "helperfuncs.h"
#include "message.h"
#include <vector>
 
extern time_t TIME;

class ListData
{
 public:
	long list_start;
	long list_position;
	bool list_ended;

	ListData() : list_start(0), list_position(0), list_ended(false) {};
	ListData(long pos, time_t t) : list_start(t), list_position(pos), list_ended(false) {};
};

/* $ModDesc: A module overriding /list, and making it safe - stop those sendq problems. */
 
typedef std::vector<userrec *> UserList;
UserList listusers;    /* vector of people doing a /list */

/*
 * To create a timer which recurs every second, we inherit from InspTimer.
 * InspTimer is only one-shot however, so at the end of each Tick() we simply
 * insert another of ourselves into the pending queue :)
 */
class ListTimer : public InspTimer
{
 private:

	Server* Srv;
	char buffer[MAXBUF];
	chanrec *chan;

 public:

	ListTimer(long interval, Server* Me) : InspTimer(interval,TIME), Srv(Me)
	{
	}

	virtual void Tick(time_t TIME)
	{
                bool go_again = true;

                while (go_again)
                {
                        go_again = false;
                        for (UserList::iterator iter = listusers.begin(); iter != listusers.end(); iter++)
                        {
                                /*
                                 * What we do here:
                                 *  - Get where they are up to
                                 *  - If it's > GetChannelCount, erase them from the iterator, set go_again to true
                                 *  - If not, spool the next 20 channels
                                 */
                                userrec* u = (userrec*)(*iter);
                                ListData* ld = (ListData*)u->GetExt("safelist_cache");
                                if (ld->list_position > Srv->GetChannelCount())
                                {
                                        u->Shrink("safelist_cache");
                                        delete ld;
                                        listusers.erase(iter);
                                        go_again = true;
                                        break;
                                }

                                log(DEBUG, "m_safelist.so: resuming spool of list to client %s at channel %ld", u->nick, ld->list_position);
                                chan = NULL;
                                /* Attempt to fill up to half the user's sendq with /LIST output */
                                long amount_sent = 0;
                                do
                                {
                                        log(DEBUG,"Channel %ld",ld->list_position);
					if (!ld->list_position)
						WriteServ(u->fd,"321 %s Channel :Users Name",u->nick);
                                        chan = Srv->GetChannelIndex(ld->list_position);
                                        /* spool details */
					bool has_user = (chan && chan->HasUser(u));
                                        if ((chan) && (((!(chan->binarymodes & CM_PRIVATE)) && (!(chan->binarymodes & CM_SECRET))) || (has_user)))
                                        {
                                                /* Increment total plus linefeed */
						long users = usercount_i(chan);
						/* If there are only invisible users on the channel, dont show it */
						if (users)
						{
							int counter = snprintf(buffer,MAXBUF,"322 %s %s %ld :[+%s] %s",u->nick,chan->name,users,chanmodes(chan,has_user),chan->topic);
							amount_sent += counter + 4 + Srv->GetServerName().length();
							log(DEBUG,"m_safelist.so: Sent %ld of safe %ld / 4",amount_sent,u->sendqmax);
							WriteServ_NoFormat(u->fd,buffer);
						}
                                        }
                                        else
                                        {
						if (!chan)
						{
	                                                if (!ld->list_ended)
	                                                {
	                                                        ld->list_ended = true;
	                                                        WriteServ(u->fd,"323 %s :End of channel list.",u->nick);
	                                                }
						}
                                        }

                                        ld->list_position++;
                                }
                                while ((chan != NULL) && (amount_sent < (u->sendqmax / 4)));
                        }
                }

		ListTimer* MyTimer = new ListTimer(1,Srv);
		Srv->AddTimer(MyTimer);
	}
};

class ModuleSafeList : public Module
{
 private:
	 Server *Srv;
	 ListTimer* MyTimer;
 public:
	ModuleSafeList(Server* Me) : Module::Module(Me)
	{
		Srv = Me;

		MyTimer = new ListTimer(1,Srv);
		Srv->AddTimer(MyTimer);
	}
 
	virtual ~ModuleSafeList()
	{
	}
 
	virtual Version GetVersion()
	{
		return Version(1,0,0,0,VF_VENDOR);
	}
 
	void Implements(char* List)
	{
		List[I_OnPreCommand] = List[I_OnCleanup] = List[I_OnUserQuit] = List[I_On005Numeric] = 1;
	}

	/*
	 * OnPreCommand()
	 *   Intercept the LIST command.
	 */ 
	virtual int OnPreCommand(std::string command, char **parameters, int pcnt, userrec *user, bool validated)
	{
		/* If the command doesnt appear to be valid, we dont want to mess with it. */
		if (!validated)
			return 0;
 
		if (command == "LIST")
		{
			return this->HandleList(parameters, pcnt, user);
		}
		return 0;
	}
	
	/*
	 * HandleList()
	 *   Handle (override) the LIST command.
	 */
	int HandleList(char** parameters, int pcnt, userrec* user)
	{
		/* First, let's check if the user is currently /list'ing */
		ListData *ld = (ListData*)user->GetExt("safelist_cache");
 
		if (ld)
		{
			/* user is already /list'ing, we don't want to do shit. */
			return 1;
		}

		time_t* last_list_time = (time_t*)user->GetExt("safelist_last");
		if (last_list_time)
		{
			if (TIME < (*last_list_time)+60)
			{
				WriteServ(user->fd,"NOTICE %s :*** Woah there, slow down a little, you can't /LIST so often!",user->nick);
				return 1;
			}

			delete last_list_time;
			user->Shrink("safelist_last");
		}
 
		/*
		 * start at channel 0! ;)
		 */
		ld = new ListData(0,TIME);
		user->Extend("safelist_cache", (char*)ld);
		listusers.push_back(user);

		time_t* llt = new time_t;
		*llt = TIME;
		user->Extend("safelist_last",(char*)llt);
	
		return 1;
	}

        virtual void OnCleanup(int target_type, void* item)
        {
                if(target_type == TYPE_USER)
		{
			userrec* u = (userrec*)item;
			ListData* ld = (ListData*)u->GetExt("safelist_cache");
			if (ld)
			{
				u->Shrink("safelist_cache");
	                        delete ld;
			}
			for (UserList::iterator iter = listusers.begin(); iter != listusers.end(); iter++)
			{
				userrec* u2 = (userrec*)(*iter);
				if (u2 == u)
				{
					listusers.erase(iter);
					break;
				}
			}
			time_t* last_list_time = (time_t*)u->GetExt("safelist_last");
			if (last_list_time)
			{
				delete last_list_time;
				u->Shrink("safelist_last");
			}
		}
	}

	virtual void On005Numeric(std::string &output)
	{
		output.append(" SAFELIST");
	}

	virtual void OnUserQuit(userrec* user, std::string message)
	{
		this->OnCleanup(TYPE_USER,user);
	}

};
 
 
 
/******************************************************************************************************/
 
class ModuleSafeListFactory : public ModuleFactory
{
 public:
	ModuleSafeListFactory()
	{
	}
 
	~ModuleSafeListFactory()
	{
	}
 
	virtual Module * CreateModule(Server* Me)
	{
		return new ModuleSafeList(Me);
	}
 
};
 
extern "C" void * init_module( void )
{
	return new ModuleSafeListFactory;
}