// Anope IRC Services <https://www.anope.org/>
//
// Copyright (C) 2003-2025 Anope Contributors
//
// Anope is free software. You can use, modify, and/or distribute it under the
// terms of version 2 of the GNU General Public License. See docs/LICENSE.txt
// for the complete terms of this license and docs/AUTHORS.txt for a list of
// contributors.
//
// Based on the original code of Epona by Lara
// Based on the original code of Services by Andy Church
//
// SPDX-License-Identifier: GPL-2.0-only

#include "module.h"
#include "modules/operserv/forbid.h"

namespace
{
	Anope::string TypeToString(ForbidType ft)
	{
		switch (ft)
		{
			case FT_NICK:
				return "NICK";
			case FT_CHAN:
				return "CHAN";
			case FT_EMAIL:
				return "EMAIL";
			case FT_REGISTER:
				return "REGISTER";
			default:
				return "UNKNOWN"; // Should never happen.
		}
	}

	ForbidType StringToType(const Anope::string &ft)
	{
		if (ft.equals_ci("NICK") || ft.equals_ci("1"))
			return FT_NICK;
		if (ft.equals_ci("CHAN") || ft.equals_ci("2"))
			return FT_CHAN;
		if (ft.equals_ci("EMAIL") || ft.equals_ci("3"))
			return FT_EMAIL;
		if (ft.equals_ci("REGISTER") || ft.equals_ci("4"))
			return FT_REGISTER;

		return FT_SIZE; // Should never happen.
	}
}

static ServiceReference<NickServService> nickserv("NickServService", "NickServ");

struct ForbidDataImpl final
	: ForbidData
	, Serializable
{
	ForbidDataImpl() : Serializable("ForbidData") { }
};

struct ForbidDataTypeImpl final
	: Serialize::Type
{
	ForbidDataTypeImpl()
		: Serialize::Type("ForbidData")
	{
	}

	void Serialize(Serializable *obj, Serialize::Data &data) const override;
	Serializable *Unserialize(Serializable *obj, Serialize::Data &data) const override;
};

void ForbidDataTypeImpl::Serialize(Serializable *obj, Serialize::Data &data) const
{
	const auto *fb = static_cast<const ForbidDataImpl *>(obj);
	data.Store("mask", fb->mask);
	data.Store("creator", fb->creator);
	data.Store("reason", fb->reason);
	data.Store("created", fb->created);
	data.Store("expires", fb->expires);
	data.Store("type", TypeToString(fb->type));
}

Serializable *ForbidDataTypeImpl::Unserialize(Serializable *obj, Serialize::Data &data) const
{
	if (!forbid_service)
		return NULL;

	ForbidDataImpl *fb;
	if (obj)
		fb = anope_dynamic_static_cast<ForbidDataImpl *>(obj);
	else
		fb = new ForbidDataImpl();

	data["mask"] >> fb->mask;
	data["creator"] >> fb->creator;
	data["reason"] >> fb->reason;
	data["created"] >> fb->created;
	data["expires"] >> fb->expires;
	Anope::string t;
	data["type"] >> t;
	fb->type = StringToType(t);

	if (fb->type == FT_SIZE)
		return NULL;

	if (!obj)
		forbid_service->AddForbid(fb);
	return fb;
}

class MyForbidService final
	: public ForbidService
{
	Serialize::Checker<std::vector<ForbidData *>[FT_SIZE - 1]> forbid_data;

	inline std::vector<ForbidData *>& forbids(unsigned t) { return (*this->forbid_data)[t - 1]; }

	void Expire(ForbidData *fd, unsigned ft, size_t idx)
	{
		Log(LOG_NORMAL, "expire/forbid", Config->GetClient("OperServ")) << "Expiring forbid for " << fd->mask << " type " << TypeToString(static_cast<ForbidType>(ft));
		this->forbids(ft).erase(this->forbids(ft).begin() + idx);
		delete fd;
	}

public:
	MyForbidService(Module *m) : ForbidService(m), forbid_data("ForbidData") { }

	~MyForbidService() override
	{
		for (const auto *forbid : GetForbids())
			delete forbid;
	}

	void AddForbid(ForbidData *d) override
	{
		this->forbids(d->type).push_back(d);
	}

	void RemoveForbid(ForbidData *d) override
	{
		std::vector<ForbidData *>::iterator it = std::find(this->forbids(d->type).begin(), this->forbids(d->type).end(), d);
		if (it != this->forbids(d->type).end())
			this->forbids(d->type).erase(it);
		delete d;
	}

	ForbidData *CreateForbid() override
	{
		return new ForbidDataImpl();
	}

	ForbidData *FindForbid(const Anope::string &mask, ForbidType ftype) override
	{
		for (unsigned i = this->forbids(ftype).size(); i > 0; --i)
		{
			ForbidData *d = this->forbids(ftype)[i - 1];

			if (!Anope::NoExpire && d->expires && Anope::CurTime >= d->expires)
			{
				Expire(d, ftype, i - 1);
				continue;
			}

			if (Anope::Match(mask, d->mask, false, true))
				return d;
		}
		return NULL;
	}

	ForbidData *FindForbidExact(const Anope::string &mask, ForbidType ftype) override
	{
		for (unsigned i = this->forbids(ftype).size(); i > 0; --i)
		{
			ForbidData *d = this->forbids(ftype)[i - 1];

			if (!Anope::NoExpire && d->expires && Anope::CurTime >= d->expires)
			{
				Expire(d, ftype, i - 1);
				continue;
			}

			if (d->mask.equals_ci(mask))
				return d;
		}
		return NULL;
	}

	std::vector<ForbidData *> GetForbids() override
	{
		std::vector<ForbidData *> f;
		for (unsigned j = FT_NICK; j < FT_SIZE; ++j)
			for (unsigned i = this->forbids(j).size(); i > 0; --i)
			{
				ForbidData *d = this->forbids(j).at(i - 1);

				if (d->expires && !Anope::NoExpire && Anope::CurTime >= d->expires)
					Expire(d, j, i - 1);
				else
					f.push_back(d);
			}

		return f;
	}
};

class CommandOSForbid final
	: public Command
{
	ServiceReference<ForbidService> fs;
public:
	CommandOSForbid(Module *creator) : Command(creator, "operserv/forbid", 1, 5), fs("ForbidService", "forbid")
	{
		this->SetDesc(_("Forbid usage of nicknames, channels, and emails"));
		this->SetSyntax(_("ADD {NICK|CHAN|EMAIL|REGISTER} [+\037expiry\037] \037entry\037 \037reason\037"));
		this->SetSyntax(_("DEL {NICK|CHAN|EMAIL|REGISTER} \037entry\037"));
		this->SetSyntax("LIST [NICK|CHAN|EMAIL|REGISTER]");
	}

	void Execute(CommandSource &source, const std::vector<Anope::string> &params) override
	{
		if (!this->fs)
			return;

		const Anope::string &command = params[0];
		const Anope::string &subcommand = params.size() > 1 ? params[1] : "";

		auto ftype = StringToType(subcommand);
		if (command.equals_ci("ADD") && params.size() > 3 && ftype != FT_SIZE)
		{
			const Anope::string &expiry = params[2][0] == '+' ? params[2] : "";
			const Anope::string &entry = !expiry.empty() ? params[3] : params[2];
			Anope::string reason;
			if (expiry.empty())
				reason = params[3] + " ";
			if (params.size() > 4)
				reason += params[4];
			reason.trim();

			if (entry.replace_all_cs("?*", "").empty())
			{
				source.Reply(_("The mask must contain at least one non wildcard character."));
				return;
			}

			time_t expiryt = 0;

			if (!expiry.empty())
			{
				expiryt = Anope::DoTime(expiry);
				if (expiryt < 0)
				{
					source.Reply(BAD_EXPIRY_TIME);
					return;
				}
				else if (expiryt)
					expiryt += Anope::CurTime;
			}

			NickAlias *target = NickAlias::Find(entry);
			if (target != NULL && Config->GetModule("nickserv").Get<bool>("secureadmins", "yes") && target->nc->IsServicesOper())
			{
				source.Reply(ACCESS_DENIED);
				return;
			}

			ForbidData *d = this->fs->FindForbidExact(entry, ftype);
			bool created = false;
			if (d == NULL)
			{
				d = new ForbidDataImpl();
				created = true;
			}

			d->mask = entry;
			d->creator = source.GetNick();
			d->reason = reason;
			d->created = Anope::CurTime;
			d->expires = expiryt;
			d->type = ftype;
			if (created)
				this->fs->AddForbid(d);

			if (Anope::ReadOnly)
				source.Reply(READ_ONLY_MODE);

			Log(LOG_ADMIN, source, this) << "to add a forbid on " << entry << " of type " << subcommand;
			source.Reply(_("Added a forbid on %s of type %s to expire on %s."), entry.c_str(), subcommand.lower().c_str(), d->expires ? Anope::strftime(d->expires, source.GetAccount()).c_str() : "never");

			/* apply forbid */
			switch (ftype)
			{
				case FT_NICK:
				{
					int na_matches = 0;

					for (const auto &[_, user] : UserListByNick)
						module->OnUserNickChange(user, "");

					for (nickalias_map::const_iterator it = NickAliasList->begin(), it_end = NickAliasList->end(); it != it_end;)
					{
						NickAlias *na = it->second;
						++it;

						d = this->fs->FindForbid(na->nick, FT_NICK);
						if (d == NULL)
							continue;

						++na_matches;

						delete na;
					}

					source.Reply(na_matches, N_("\002%d\002 nickname dropped.", "\002%d\002 nicknames dropped."), na_matches);
					break;
				}
				case FT_CHAN:
				{
					int chan_matches = 0, ci_matches = 0;

					for (channel_map::const_iterator it = ChannelList.begin(), it_end = ChannelList.end(); it != it_end;)
					{
						Channel *c = it->second;
						++it;

						d = this->fs->FindForbid(c->name, FT_CHAN);
						if (d == NULL)
							continue;

						ServiceReference<ChanServService> chanserv("ChanServService", "ChanServ");
						BotInfo *OperServ = Config->GetClient("OperServ");
						if (IRCD->CanSQLineChannel && OperServ)
						{
							time_t inhabit = Config->GetModule("chanserv").Get<time_t>("inhabit", "1m");
							XLine x(c->name, OperServ->nick, Anope::CurTime + inhabit, d->reason);
							IRCD->SendSQLine(NULL, &x);
						}
						else if (chanserv)
						{
							chanserv->Hold(c);
						}

						++chan_matches;

						for (Channel::ChanUserList::const_iterator cit = c->users.begin(), cit_end = c->users.end(); cit != cit_end;)
						{
							User *u = cit->first;
							++cit;

							if (u->server == Me || u->HasMode("OPER"))
								continue;

							reason = Anope::Format(Language::Translate(u, _("This channel has been forbidden: %s")), d->reason.c_str());

							c->Kick(source.service, u, reason);
						}
					}

					for (registered_channel_map::const_iterator it = RegisteredChannelList->begin(); it != RegisteredChannelList->end();)
					{
						ChannelInfo *ci = it->second;
						++it;

						d = this->fs->FindForbid(ci->name, FT_CHAN);
						if (d == NULL)
							continue;

						++ci_matches;

						delete ci;
					}

					source.Reply(_("\002%d\002 channel(s) cleared, and \002%d\002 channel(s) dropped."), chan_matches, ci_matches);

					break;
				}
				default:
					break;
			}

		}
		else if (command.equals_ci("DEL") && params.size() > 2 && ftype != FT_SIZE)
		{
			const Anope::string &entry = params[2];

			ForbidData *d = this->fs->FindForbidExact(entry, ftype);
			if (d != NULL)
			{
				if (Anope::ReadOnly)
					source.Reply(READ_ONLY_MODE);

				Log(LOG_ADMIN, source, this) << "to remove forbid on " << d->mask << " of type " << subcommand;
				source.Reply(_("%s deleted from the %s forbid list."), d->mask.c_str(), subcommand.c_str());
				this->fs->RemoveForbid(d);
			}
			else
				source.Reply(_("Forbid on %s was not found."), entry.c_str());
		}
		else if (command.equals_ci("LIST"))
		{
			const std::vector<ForbidData *> &forbids = this->fs->GetForbids();
			if (forbids.empty())
				source.Reply(_("Forbid list is empty."));
			else
			{
				ListFormatter list(source.GetAccount());
				list.AddColumn(_("Mask")).AddColumn(_("Type")).AddColumn(_("Creator")).AddColumn(_("Expires")).AddColumn(_("Reason"));
				list.SetFlexible([](ListFormatter::ListEntry &row)
				{
					return row["Reason"].empty()
						? _("\002{mask}\002 on {type} -- created by {creator}; expires in {expires}")
						: _("\002{mask}\002 on {type} -- created by {creator}; expires in {expires} ({reason})");
				});

				size_t shown = 0;
				for (auto *forbid : forbids)
				{
					if (ftype != FT_SIZE && ftype != forbid->type)
						continue;

					auto stype = TypeToString(forbid->type);
					if (stype == FT_SIZE)
						continue;

					ListFormatter::ListEntry entry;
					entry["Mask"] = forbid->mask;
					entry["Type"] = stype;
					entry["Creator"] = forbid->creator;
					entry["Expires"] = forbid->expires ? Anope::strftime(forbid->expires, NULL, true).c_str() : TIME_NEVER;
					entry["Reason"] = forbid->reason;
					list.AddEntry(entry);
					++shown;
				}

				if (!shown)
				{
					source.Reply(_("There are no forbids of type %s."), subcommand.upper().c_str());
				}
				else
				{
					source.Reply(_("Forbid list:"));
					list.SendTo(source);

					if (shown >= forbids.size())
						source.Reply(_("End of forbid list."));
					else
						source.Reply(_("End of forbid list - %zu/%zu entries shown."), shown, forbids.size());
				}
			}
		}
		else
			this->OnSyntaxError(source, command);
	}

	bool OnHelp(CommandSource &source, const Anope::string &subcommand) override
	{
		this->SendSyntax(source);
		source.Reply(" ");
		source.Reply(_(
			"Forbid allows you to forbid usage of certain nicknames, channels, "
			"and email addresses. Wildcards are accepted for all entries."
		));

		const Anope::string &regexengine = Config->GetBlock("options").Get<const Anope::string>("regexengine");
		if (!regexengine.empty())
		{
			source.Reply(" ");
			source.Reply(_(
					"Regex matches are also supported using the %s engine. "
					"Enclose your pattern in // if this is desired."
				),
				regexengine.c_str());
		}

		return true;
	}
};

class OSForbid final
	: public Module
{
	MyForbidService forbidService;
	ForbidDataTypeImpl forbiddata_type;
	CommandOSForbid commandosforbid;

public:
	OSForbid(const Anope::string &modname, const Anope::string &creator)
		: Module(modname, creator, VENDOR)
		, forbidService(this)
		, commandosforbid(this)
	{
	}

	void OnUserConnect(User *u, bool &exempt) override
	{
		if (u->Quitting() || exempt)
			return;

		this->OnUserNickChange(u, "");
	}

	void OnUserNickChange(User *u, const Anope::string &) override
	{
		if (u->HasMode("OPER"))
			return;

		ForbidData *d = this->forbidService.FindForbid(u->nick, FT_NICK);
		if (d != NULL)
		{
			BotInfo *bi = Config->GetClient("NickServ");
			if (!bi)
				bi = Config->GetClient("OperServ");
			if (bi)
				u->SendMessage(bi, _("This nickname has been forbidden: %s"), d->reason.c_str());
			if (nickserv)
				nickserv->Collide(u, NULL);
		}
	}

	EventReturn OnCheckKick(User *u, Channel *c, Anope::string &mask, Anope::string &reason) override
	{
		BotInfo *OperServ = Config->GetClient("OperServ");
		if (u->HasMode("OPER") || !OperServ)
			return EVENT_CONTINUE;

		ForbidData *d = this->forbidService.FindForbid(c->name, FT_CHAN);
		if (d != NULL)
		{
			ServiceReference<ChanServService> chanserv("ChanServService", "ChanServ");
			if (IRCD->CanSQLineChannel)
			{
				time_t inhabit = Config->GetModule("chanserv").Get<time_t>("inhabit", "1m");
				XLine x(c->name, OperServ->nick, Anope::CurTime + inhabit, d->reason);
				IRCD->SendSQLine(NULL, &x);
			}
			else if (chanserv)
			{
				chanserv->Hold(c);
			}

			reason = Anope::Format(Language::Translate(u, _("This channel has been forbidden: %s")), d->reason.c_str());

			return EVENT_STOP;
		}

		return EVENT_CONTINUE;
	}

	EventReturn OnPreCommand(CommandSource &source, Command *command, std::vector<Anope::string> &params) override
	{
		if (command->name == "nickserv/info" && !params.empty() && params[0][0] != '=')
		{
			ForbidData *d = this->forbidService.FindForbid(params[0], FT_NICK);
			if (d != NULL)
			{
				if (source.IsOper())
					source.Reply(_("Nick \002%s\002 is forbidden by %s: %s"), params[0].c_str(), d->creator.c_str(), d->reason.c_str());
				else
					source.Reply(_("Nick \002%s\002 is forbidden."), params[0].c_str());
				return EVENT_STOP;
			}
		}
		else if (command->name == "chanserv/info" && params.size() > 0)
		{
			ForbidData *d = this->forbidService.FindForbid(params[0], FT_CHAN);
			if (d != NULL)
			{
				if (source.IsOper())
					source.Reply(_("Channel \002%s\002 is forbidden by %s: %s"), params[0].c_str(), d->creator.c_str(), d->reason.c_str());
				else
					source.Reply(_("Channel \002%s\002 is forbidden."), params[0].c_str());
				return EVENT_STOP;
			}
		}
		else if (source.IsOper())
			return EVENT_CONTINUE;
		else if (command->name == "nickserv/register" && params.size() > 1)
		{
			ForbidData *d = this->forbidService.FindForbid(source.GetNick(), FT_REGISTER);
			if (d != NULL)
			{
				source.Reply(NICK_CANNOT_BE_REGISTERED, source.GetNick().c_str());
				return EVENT_STOP;
			}

			d = this->forbidService.FindForbid(params[1], FT_EMAIL);
			if (d != NULL)
			{
				source.Reply(_("Your email address is not allowed, choose a different one."));
				return EVENT_STOP;
			}
		}
		else if (command->name == "nickserv/set/email" && params.size() > 0)
		{
			ForbidData *d = this->forbidService.FindForbid(params[0], FT_EMAIL);
			if (d != NULL)
			{
				source.Reply(_("Your email address is not allowed, choose a different one."));
				return EVENT_STOP;
			}
		}
		else if (command->name == "chanserv/register" && !params.empty())
		{
			ForbidData *d = this->forbidService.FindForbid(params[0], FT_REGISTER);
			if (d != NULL)
			{
				source.Reply(CHAN_X_INVALID, params[0].c_str());
				return EVENT_STOP;
			}
		}

		return EVENT_CONTINUE;
	}
};

MODULE_INIT(OSForbid)