/*       +------------------------------------+
 *       | Inspire Internet Relay Chat Daemon |
 *       +------------------------------------+
 *
 *  InspIRCd: (C) 2002-2011 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"

/* $ModDesc: Implements config tags which allow changing characters allowed in channel names */

static std::bitset<256> allowedmap;

class NewIsChannelHandler : public HandlerBase2<bool, const char*, size_t>
{
 public:
	NewIsChannelHandler() { }
	virtual ~NewIsChannelHandler() { }
	virtual bool Call(const char*, size_t);
};

bool NewIsChannelHandler::Call(const char* c, size_t max)
{
		/* check for no name - don't check for !*chname, as if it is empty, it won't be '#'! */
		if (!c || *c++ != '#')
			return false;

		while (*c && --max)
		{
			unsigned int i = *c++ & 0xFF;
			if (!allowedmap[i])
				return false;
		}
		// a name of exactly max length will have max = 1 here; the null does not trigger --max
		return max;
}

class ModuleChannelNames : public Module
{
 private:
	NewIsChannelHandler myhandler;
	caller2<bool, const char*, size_t> rememberer;
	bool badchan;

 public:
	ModuleChannelNames() : rememberer(ServerInstance->IsChannel)
	{
		ServerInstance->IsChannel = &myhandler;
	}

	void init()
	{
		badchan = false;
		Implementation eventlist[] = { I_OnUserKick };
		ServerInstance->Modules->Attach(eventlist, this, sizeof(eventlist)/sizeof(Implementation));
	}

	void ValidateChans()
	{
		badchan = true;
		std::vector<Channel*> chanvec;
		irc::modestacker modes;
		ModeHandler* mh = ServerInstance->Modes->FindMode("registered");
		if (mh) modes.push(irc::modechange(mh->id, "", false));
		mh = ServerInstance->Modes->FindMode("permanent");
		if (mh) modes.push(irc::modechange(mh->id, "", false));
		for (chan_hash::const_iterator i = ServerInstance->chanlist->begin(); i != ServerInstance->chanlist->end(); ++i)
		{
			if (!ServerInstance->IsChannel(i->second->name.c_str(), MAXBUF))
				chanvec.push_back(i->second);
		}
		std::vector<Channel*>::reverse_iterator c2 = chanvec.rbegin();
		while (c2 != chanvec.rend())
		{
			Channel* c = *c2++;
			irc::modestacker tmpmodes(modes);
			ServerInstance->SendMode(ServerInstance->FakeClient, c, tmpmodes, true);
			const UserMembList* users = c->GetUsers();
			for(UserMembCIter j = users->begin(); j != users->end(); ++j)
				if (IS_LOCAL(j->first))
					c->KickUser(ServerInstance->FakeClient, j->first, "Channel name no longer valid");
		}
		badchan = false;
	}

	virtual void ReadConfig(ConfigReadStatus&)
	{
		std::string denyToken = ServerInstance->Config->GetTag("channames")->getString("denyrange");
		std::string allowToken = ServerInstance->Config->GetTag("channames")->getString("allowrange");
		allowedmap.set();

		irc::portparser denyrange(denyToken, false);
		int denyno = -1;
		while (0 != (denyno = denyrange.GetToken()))
			allowedmap[denyno & 0xFF] = false;

		irc::portparser allowrange(allowToken, false);
		int allowno = -1;
		while (0 != (allowno = allowrange.GetToken()))
			allowedmap[allowno & 0xFF] = true;

		allowedmap[0x07] = false; // BEL
		allowedmap[0x20] = false; // ' '
		allowedmap[0x2C] = false; // ','

		ValidateChans();
	}

	virtual void OnUserKick(User* source, Membership* memb, const std::string &reason, CUList& except_list)
	{
		if (badchan)
		{
			const UserMembList* users = memb->chan->GetUsers();
			for(UserMembCIter i = users->begin(); i != users->end(); i++)
				if (i->first != memb->user)
					except_list.insert(i->first);
		}
	}

	virtual ~ModuleChannelNames()
	{
		ServerInstance->IsChannel = rememberer;
		ValidateChans();
	}

	virtual Version GetVersion()
	{
		return Version("Implements config tags which allow changing characters allowed in channel names", VF_VENDOR);
	}
};

MODULE_INIT(ModuleChannelNames)