/*
 * InspIRCd -- Internet Relay Chat Daemon
 *
 *   Copyright (C) 2022 Sadie Powell <sadie@witchery.services>
 *
 * This file is part of InspIRCd.  InspIRCd is free software: you can
 * redistribute it and/or modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation, version 2.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */


#pragma once

enum
{
	// From RFC 1459.
	ERR_CANNOTSENDTOCHAN = 404,

	// InspIRCd-specific.
	ERR_CANNOTSENDTOUSER = 531,
	ERR_INVALIDMODEPARAM = 696,
};

namespace Numerics
{
	class CannotSendTo;
	class ChannelPrivilegesNeeded;
	class InvalidModeParameter;
	class NoSuchChannel;
	class NoSuchNick;
}

/** Helper for the ERR_CANNOTSENDTOCHAN and ERR_CANNOTSENDTOUSER numerics. */
class Numerics::CannotSendTo final
	: public Numeric::Numeric
{
public:
	CannotSendTo(Channel* chan, const std::string& message)
		: Numeric(ERR_CANNOTSENDTOCHAN)
	{
		push(chan->name);
		push(message);
	}

	CannotSendTo(Channel* chan, const std::string& what, ModeHandler* mh)
		: Numeric(ERR_CANNOTSENDTOCHAN)
	{
		push(chan->name);
		push(InspIRCd::Format("You cannot send %s to this channel whilst the +%c (%s) mode is set.",
			what.c_str(), mh->GetModeChar(), mh->name.c_str()));
	}

	CannotSendTo(Channel* chan, const std::string& what, char extban, const std::string& extbandesc)
		: Numeric(ERR_CANNOTSENDTOCHAN)
	{
		push(chan->name);
		push(InspIRCd::Format("You cannot send %s to this channel whilst %s %c: (%s) extban is set matching you.",
			what.c_str(), strchr("AEIOUaeiou", extban) ? "an" : "a", extban, extbandesc.c_str()));
	}

	CannotSendTo(User* user, const std::string& message)
		: Numeric(ERR_CANNOTSENDTOUSER)
	{
		push(user->registered & REG_NICK ? user->nick : "*");
		push(message);
	}

	CannotSendTo(User* user, const std::string& what, ModeHandler* mh, bool self = false)
		: Numeric(ERR_CANNOTSENDTOUSER)
	{
		push(user->registered & REG_NICK ? user->nick : "*");
		push(InspIRCd::Format("You cannot send %s to this user whilst %s have the +%c (%s) mode set.",
			what.c_str(), self ? "you" : "they", mh->GetModeChar(), mh->name.c_str()));
	}
};

/* Helper for the ERR_CHANOPRIVSNEEDED numeric. */
class Numerics::ChannelPrivilegesNeeded : public Numeric::Numeric
{
public:
	ChannelPrivilegesNeeded(Channel* chan, ModeHandler::Rank rank, const std::string& message)
		: Numeric(ERR_CHANOPRIVSNEEDED)
	{
		push(chan->name);

		const PrefixMode* pm = ServerInstance->Modes.FindNearestPrefixMode(rank);
		if (pm)
			push(InspIRCd::Format("You must be a channel %s or higher to %s.", pm->name.c_str(), message.c_str()));
		else
			push(InspIRCd::Format("You do not have the required channel privileges to %s.", message.c_str()));
	}
};

/* Helper for the ERR_INVALIDMODEPARAM numeric. */
class Numerics::InvalidModeParameter final
	: public Numeric::Numeric
{
private:
	void push_message(ModeHandler* mode, const std::string& message)
	{
		if (!message.empty())
		{
			// The caller has specified their own message.
			push(message);
			return;
		}

		const std::string& syntax = mode->GetSyntax();
		if (!syntax.empty())
		{
			// If the mode has a syntax hint we include it in the message.
			push(InspIRCd::Format("Invalid %s mode parameter. Syntax: %s.", mode->name.c_str(), syntax.c_str()));
		}
		else
		{
			// Otherwise, send it without.
			push(InspIRCd::Format("Invalid %s mode parameter.", mode->name.c_str()));
		}
	}

public:
	InvalidModeParameter(Channel* chan, ModeHandler* mode, const std::string& parameter, const std::string& message = "")
		: Numeric(ERR_INVALIDMODEPARAM)
	{
		push(chan->name);
		push(mode->GetModeChar());
		push(parameter);
		push_message(mode, message);
	}

	InvalidModeParameter(User* user, ModeHandler* mode, const std::string& parameter, const std::string& message = "")
		: Numeric(ERR_INVALIDMODEPARAM)
	{
		push(user->registered & REG_NICK ? user->nick : "*");
		push(mode->GetModeChar());
		push(parameter);
		push_message(mode, message);
	}
};

/** Helper for the ERR_NOSUCHCHANNEL numeric. */
class Numerics::NoSuchChannel final
	: public Numeric::Numeric
{
public:
	NoSuchChannel(const std::string& chan)
		: Numeric(ERR_NOSUCHCHANNEL)
	{
		push(chan.empty() ? "*" : chan);
		push("No such channel");
	}
};

/** Helper for the ERR_NOSUCHNICK numeric. */
class Numerics::NoSuchNick final
	: public Numeric::Numeric
{
public:
	NoSuchNick(const std::string& nick)
		: Numeric(ERR_NOSUCHNICK)
	{
		push(nick.empty() ? "*" : nick);
		push("No such nick");
	}
};