/*       +------------------------------------+
 *       | Inspire Internet Relay Chat Daemon |
 *       +------------------------------------+
 *
 *  InspIRCd: (C) 2002-2009 InspIRCd Development Team
 * See: http://wiki.inspircd.org/Credits
 *
 * This program is free but copyrighted software; see
 *	    the file COPYING for details.
 *
 * ---------------------------------------------------
 */

#include "inspircd.h"
#include <stdarg.h>

class DelayJoinMode : public ModeHandler
{
 private:
	CUList empty;
	Module* Creator;
 public:
	DelayJoinMode(InspIRCd* Instance, Module* Parent) : ModeHandler(Instance, 'D', 0, 0, false, MODETYPE_CHANNEL, false, 0, '@'), Creator(Parent) {};

	ModeAction OnModeChange(User* source, User* dest, Channel* channel, std::string &parameter, bool adding, bool);
};

class ModuleDelayJoin : public Module
{
 private:
	DelayJoinMode djm;
	CUList nl;
 public:
	ModuleDelayJoin(InspIRCd* Me) : Module(Me), djm(Me, this)
	{
		if (!ServerInstance->Modes->AddMode(&djm))
			throw ModuleException("Could not add new modes!");
		Implementation eventlist[] = { I_OnUserJoin, I_OnUserPart, I_OnUserKick, I_OnUserQuit, I_OnNamesListItem, I_OnText, I_OnHostCycle };
		ServerInstance->Modules->Attach(eventlist, this, 7);
	}
	virtual ~ModuleDelayJoin();
	virtual Version GetVersion();
	virtual void OnNamesListItem(User* issuer, User* user, Channel* channel, std::string &prefixes, std::string &nick);
	virtual void OnUserJoin(User* user, Channel* channel, bool sync, bool &silent);
	void CleanUser(User* user);
	bool OnHostCycle(User* user);
	void OnUserPart(User* user, Channel* channel, std::string &partmessage, bool &silent);
	void OnUserKick(User* source, User* user, Channel* chan, const std::string &reason, bool &silent);
	void OnUserQuit(User* user, const std::string &reason, const std::string &oper_message);
	void OnText(User* user, void* dest, int target_type, const std::string &text, char status, CUList &exempt_list);
	void WriteCommonFrom(User *user, Channel* channel, const char* text, ...) CUSTOM_PRINTF(4, 5);
};

/* $ModDesc: Allows for delay-join channels (+D) where users dont appear to join until they speak */

ModeAction DelayJoinMode::OnModeChange(User* source, User* dest, Channel* channel, std::string &parameter, bool adding, bool)
{
	/* no change */
	if (channel->IsModeSet('D') == adding)
		return MODEACTION_DENY;

	if (!adding)
	{
		/*
		 * Make all users visible, as +D is being removed. If we don't do this,
		 * they remain permanently invisible on this channel!
		 */
		CUList* names = channel->GetUsers();
		for (CUListIter n = names->begin(); n != names->end(); ++n)
			Creator->OnText(n->first, channel, TYPE_CHANNEL, "", 0, empty);
	}
	channel->SetMode('D', adding);
	return MODEACTION_ALLOW;
}

ModuleDelayJoin::~ModuleDelayJoin()
{
	ServerInstance->Modes->DelMode(&djm);
}

Version ModuleDelayJoin::GetVersion()
{
	return Version("$Id$", VF_COMMON | VF_VENDOR, API_VERSION);
}

void ModuleDelayJoin::OnNamesListItem(User* issuer, User* user, Channel* channel, std::string &prefixes, std::string &nick)
{
	if (!channel->IsModeSet('D'))
		return;

	if (nick.empty())
		return;

	/* don't prevent the user from seeing themself */
	if (issuer == user)
		return;

	/* If the user is hidden by delayed join, hide them from the NAMES list */
	if (user->GetExt("delayjoin_"+channel->name))
		nick.clear();
}

void ModuleDelayJoin::OnUserJoin(User* user, Channel* channel, bool sync, bool &silent)
{
	if (channel->IsModeSet('D'))
	{
		silent = true;
		/* Because we silenced the event, make sure it reaches the user whos joining (but only them of course) */
		user->WriteFrom(user, "JOIN %s", channel->name.c_str());

		/* This metadata tells the module the user is delayed join on this specific channel */
		user->Extend("delayjoin_"+channel->name);

		/* This metadata tells the module the user is delayed join on at least one (or more) channels.
		 * It is only cleared when the user is no longer on ANY +D channels.
		 */
		if (!user->GetExt("delayjoin"))
			user->Extend("delayjoin");
	}
}

void ModuleDelayJoin::CleanUser(User* user)
{
	/* Check if the user is hidden on any other +D channels, if so don't take away the
	 * metadata that says they're hidden on one or more channels
	 */
	for (UCListIter f = user->chans.begin(); f != user->chans.end(); f++)
		if (user->GetExt("delayjoin_" + f->first->name))
			return;

	user->Shrink("delayjoin");
}

void ModuleDelayJoin::OnUserPart(User* user, Channel* channel, std::string &partmessage, bool &silent)
{
	if (!channel->IsModeSet('D'))
		return;
	if (user->GetExt("delayjoin_"+channel->name))
	{
		user->Shrink("delayjoin_"+channel->name);
		silent = true;
		/* Because we silenced the event, make sure it reaches the user whos leaving (but only them of course) */
		user->WriteFrom(user, "PART %s%s%s", channel->name.c_str(), partmessage.empty() ? "" : " :", partmessage.empty() ? "" : partmessage.c_str());
		CleanUser(user);
	}
}

void ModuleDelayJoin::OnUserKick(User* source, User* user, Channel* chan, const std::string &reason, bool &silent)
{
	if (!chan->IsModeSet('D'))
		return;
	/* Send silenced event only to the user being kicked and the user doing the kick */
	if (user->GetExt("delayjoin_"+chan->name))
	{
		user->Shrink("delayjoin_"+chan->name);
		silent = true;
		user->WriteFrom(source, "KICK %s %s %s", chan->name.c_str(), user->nick.c_str(), reason.c_str());
		CleanUser(user);
	}
}

bool ModuleDelayJoin::OnHostCycle(User* user)
{
	return user->GetExt("delayjoin");
}

void ModuleDelayJoin::OnUserQuit(User* user, const std::string &reason, const std::string &oper_message)
{
	Command* parthandler = ServerInstance->Parser->GetHandler("PART");
	if (parthandler && user->GetExt("delayjoin"))
	{
		for (UCListIter f = user->chans.begin(); f != user->chans.end(); f++)
		{
			Channel* chan = f->first;
			if (user->GetExt("delayjoin_"+chan->name))
			{
				std::vector<std::string> parameters;
				parameters.push_back(chan->name);
				/* Send a fake PART from the channel, which will be silent */
				parthandler->Handle(parameters, user);
			}
		}
		user->Shrink("delayjoin");
	}
}

void ModuleDelayJoin::OnText(User* user, void* dest, int target_type, const std::string &text, char status, CUList &exempt_list)
{
	/* Server origin */
	if (!user)
		return;

	if (target_type != TYPE_CHANNEL)
		return;

	Channel* channel = (Channel*) dest;

	if (!user->GetExt("delayjoin_"+channel->name))
		return;

	/* Display the join to everyone else (the user who joined got it earlier) */
	this->WriteCommonFrom(user, channel, "JOIN %s", channel->name.c_str());

	std::string n = this->ServerInstance->Modes->ModeString(user, channel);
	if (n.length() > 0)
		this->WriteCommonFrom(user, channel, "MODE %s +%s", channel->name.c_str(), n.c_str());

	/* Shrink off the neccessary metadata for a specific channel */
	user->Shrink("delayjoin_"+channel->name);
	CleanUser(user);
}

// .. is there a real need to duplicate WriteCommonExcept?
void ModuleDelayJoin::WriteCommonFrom(User *user, Channel* channel, const char* text, ...)
{
	va_list argsPtr;
	char textbuffer[MAXBUF];
	char tb[MAXBUF];

	va_start(argsPtr, text);
	vsnprintf(textbuffer, MAXBUF, text, argsPtr);
	va_end(argsPtr);
	snprintf(tb,MAXBUF,":%s %s",user->GetFullHost().c_str(), textbuffer);

	CUList *ulist = channel->GetUsers();

	for (CUList::iterator i = ulist->begin(); i != ulist->end(); i++)
	{
		/* User doesnt get a JOIN sent to themselves */
		if (user == i->first)
			continue;

		/* Users with a visibility state that hides them dont appear */
		if (user->Visibility && !user->Visibility->VisibleTo(i->first))
			continue;

		i->first->Write(std::string(tb));
	}
}

MODULE_INIT(ModuleDelayJoin)