/*
 *
 * (C) 2003-2022 Anope Team
 * Contact us at team@anope.org
 *
 * Please read COPYING and README for further details.
 *
 * Based on the original code of Epona by Lara.
 * Based on the original code of Services by Andy Church.
 */

#include "services.h"
#include "modules.h"
#include "protocol.h"
#include "users.h"
#include "servers.h"
#include "config.h"
#include "uplink.h"
#include "bots.h"
#include "channels.h"

IRCDProto *IRCD = NULL;

IRCDProto::IRCDProto(Module *creator, const Anope::string &p) : Service(creator, "IRCDProto", creator->name), proto_name(p)
{
	DefaultPseudoclientModes = "+io";
	CanSVSNick = CanSVSJoin = CanSetVHost = CanSetVIdent = CanSNLine = CanSQLine = CanSQLineChannel
		= CanSZLine = CanSVSHold = CanSVSO = CanCertFP = RequiresID = AmbiguousID = false;
	MaxModes = 3;
	MaxLine = 512;

	if (IRCD == NULL)
		IRCD = this;
}

IRCDProto::~IRCDProto()
{
	if (IRCD == this)
		IRCD = NULL;
}

const Anope::string &IRCDProto::GetProtocolName()
{
	return this->proto_name;
}

static inline char nextID(int pos, Anope::string &buf)
{
	char &c = buf[pos];
	if (c == 'Z')
		c = '0';
	else if (c != '9')
		++c;
	else if (pos)
		c = 'A';
	else
		c = '0';
	return c;
}

Anope::string IRCDProto::UID_Retrieve()
{
	if (!IRCD || !IRCD->RequiresID)
		return "";

	static Anope::string current_uid = "AAAAAA";

	do
	{
		int current_len = current_uid.length() - 1;
		while (current_len >= 0 && nextID(current_len--, current_uid) == 'A');
	}
	while (User::Find(Me->GetSID() + current_uid) != NULL);

	return Me->GetSID() + current_uid;
}

Anope::string IRCDProto::SID_Retrieve()
{
	if (!IRCD || !IRCD->RequiresID)
		return "";

	static Anope::string current_sid = Config->GetBlock("serverinfo")->Get<const Anope::string>("id");
	if (current_sid.empty())
		current_sid = "00A";

	do
	{
		int current_len = current_sid.length() - 1;
		while (current_len >= 0 && nextID(current_len--, current_sid) == 'A');
	}
	while (Server::Find(current_sid) != NULL);

	return current_sid;
}

void IRCDProto::SendKill(const MessageSource &source, const Anope::string &target, const Anope::string &reason)
{
	UplinkSocket::Message(source) << "KILL " << target << " :" << reason;
}

void IRCDProto::SendSVSKillInternal(const MessageSource &source, User *user, const Anope::string &buf)
{
	UplinkSocket::Message(source) << "KILL " << user->GetUID() << " :" << buf;
}

void IRCDProto::SendModeInternal(const MessageSource &source, const Channel *dest, const Anope::string &buf)
{
	UplinkSocket::Message(source) << "MODE " << dest->name << " " << buf;
}

void IRCDProto::SendModeInternal(const MessageSource &source, User *dest, const Anope::string &buf)
{
	UplinkSocket::Message(source) << "MODE " << dest->GetUID() << " " << buf;
}

void IRCDProto::SendKickInternal(const MessageSource &source, const Channel *c, User *u, const Anope::string &r)
{
	if (!r.empty())
		UplinkSocket::Message(source) << "KICK " << c->name << " " << u->GetUID() << " :" << r;
	else
		UplinkSocket::Message(source) << "KICK " << c->name << " " << u->GetUID();
}

void IRCDProto::SendNoticeInternal(const MessageSource &source, const Anope::string &dest, const Anope::string &msg)
{
	UplinkSocket::Message(source) << "NOTICE " << dest << " :" << msg;
}

void IRCDProto::SendPrivmsgInternal(const MessageSource &source, const Anope::string &dest, const Anope::string &buf)
{
	UplinkSocket::Message(source) << "PRIVMSG " << dest << " :" << buf;
}

void IRCDProto::SendQuitInternal(User *u, const Anope::string &buf)
{
	if (!buf.empty())
		UplinkSocket::Message(u) << "QUIT :" << buf;
	else
		UplinkSocket::Message(u) << "QUIT";
}

void IRCDProto::SendPartInternal(User *u, const Channel *chan, const Anope::string &buf)
{
	if (!buf.empty())
		UplinkSocket::Message(u) << "PART " << chan->name << " :" << buf;
	else
		UplinkSocket::Message(u) << "PART " << chan->name;
}

void IRCDProto::SendGlobopsInternal(const MessageSource &source, const Anope::string &buf)
{
	UplinkSocket::Message(source) << "GLOBOPS :" << buf;
}

void IRCDProto::SendCTCPInternal(const MessageSource &source, const Anope::string &dest, const Anope::string &buf)
{
	Anope::string s = Anope::NormalizeBuffer(buf);
	this->SendNoticeInternal(source, dest, "\1" + s + "\1");
}

void IRCDProto::SendNumericInternal(int numeric, const Anope::string &dest, const Anope::string &buf)
{
	Anope::string n = stringify(numeric);
	if (numeric < 10)
		n = "0" + n;
	if (numeric < 100)
		n = "0" + n;
	UplinkSocket::Message(Me) << n << " " << dest << " " << buf;
}

void IRCDProto::SendTopic(const MessageSource &source, Channel *c)
{
	UplinkSocket::Message(source) << "TOPIC " << c->name << " :" << c->topic;
}

void IRCDProto::SendSVSKill(const MessageSource &source, User *user, const char *fmt, ...)
{
	if (!user || !fmt)
		return;

	va_list args;
	char buf[BUFSIZE] = "";
	va_start(args, fmt);
	vsnprintf(buf, BUFSIZE - 1, fmt, args);
	va_end(args);
	SendSVSKillInternal(source, user, buf);
}

void IRCDProto::SendMode(const MessageSource &source, const Channel *dest, const char *fmt, ...)
{
	va_list args;
	char buf[BUFSIZE] = "";
	va_start(args, fmt);
	vsnprintf(buf, BUFSIZE - 1, fmt, args);
	va_end(args);
	SendModeInternal(source, dest, buf);
}

void IRCDProto::SendMode(const MessageSource &source, User *u, const char *fmt, ...)
{
	va_list args;
	char buf[BUFSIZE] = "";
	va_start(args, fmt);
	vsnprintf(buf, BUFSIZE - 1, fmt, args);
	va_end(args);
	SendModeInternal(source, u, buf);
}

void IRCDProto::SendKick(const MessageSource &source, const Channel *chan, User *user, const char *fmt, ...)
{
	if (!chan || !user)
		return;

	va_list args;
	char buf[BUFSIZE] = "";
	va_start(args, fmt);
	vsnprintf(buf, BUFSIZE - 1, fmt, args);
	va_end(args);
	SendKickInternal(source, chan, user, buf);
}

void IRCDProto::SendNotice(const MessageSource &source, const Anope::string &dest, const char *fmt, ...)
{
	va_list args;
	char buf[BUFSIZE] = "";
	va_start(args, fmt);
	vsnprintf(buf, BUFSIZE - 1, fmt, args);
	va_end(args);
	SendNoticeInternal(source, dest, buf);
}

void IRCDProto::SendAction(const MessageSource &source, const Anope::string &dest, const char *fmt, ...)
{
	va_list args;
	char buf[BUFSIZE] = "";
	va_start(args, fmt);
	vsnprintf(buf, BUFSIZE - 1, fmt, args);
	va_end(args);
	Anope::string actionbuf = Anope::string("\1ACTION ") + buf + '\1';
	SendPrivmsgInternal(source, dest, actionbuf);
}

void IRCDProto::SendPrivmsg(const MessageSource &source, const Anope::string &dest, const char *fmt, ...)
{
	va_list args;
	char buf[BUFSIZE] = "";
	va_start(args, fmt);
	vsnprintf(buf, BUFSIZE - 1, fmt, args);
	va_end(args);
	SendPrivmsgInternal(source, dest, buf);
}

void IRCDProto::SendQuit(User *u, const char *fmt, ...)
{
	va_list args;
	char buf[BUFSIZE] = "";
	va_start(args, fmt);
	vsnprintf(buf, BUFSIZE - 1, fmt, args);
	va_end(args);
	SendQuitInternal(u, buf);
}

void IRCDProto::SendPing(const Anope::string &servname, const Anope::string &who)
{
	if (servname.empty())
		UplinkSocket::Message(Me) << "PING " << who;
	else
		UplinkSocket::Message(Me) << "PING " << servname << " " << who;
}

/**
 * Send a PONG reply to a received PING.
 * servname should be left NULL to send a one param reply.
 * @param servname Daemon or client that is responding to the PING.
 * @param who Origin of the PING and destination of the PONG message.
 **/
void IRCDProto::SendPong(const Anope::string &servname, const Anope::string &who)
{
	if (servname.empty())
		UplinkSocket::Message(Me) << "PONG " << who;
	else
		UplinkSocket::Message(Me) << "PONG " << servname << " " << who;
}

void IRCDProto::SendInvite(const MessageSource &source, const Channel *c, User *u)
{
	UplinkSocket::Message(source) << "INVITE " << u->GetUID() << " " << c->name;
}

void IRCDProto::SendPart(User *user, const Channel *chan, const char *fmt, ...)
{
	if (fmt)
	{
		va_list args;
		char buf[BUFSIZE] = "";
		va_start(args, fmt);
		vsnprintf(buf, BUFSIZE - 1, fmt, args);
		va_end(args);
		SendPartInternal(user, chan, buf);
	}
	else
		SendPartInternal(user, chan, "");
}

void IRCDProto::SendGlobops(const MessageSource &source, const char *fmt, ...)
{
	va_list args;
	char buf[BUFSIZE] = "";
	va_start(args, fmt);
	vsnprintf(buf, BUFSIZE - 1, fmt, args);
	va_end(args);
	SendGlobopsInternal(source, buf);
}

void IRCDProto::SendSquit(Server *s, const Anope::string &message)
{
	UplinkSocket::Message() << "SQUIT " << s->GetSID() << " :" << message;
}

void IRCDProto::SendNickChange(User *u, const Anope::string &newnick)
{
	UplinkSocket::Message(u) << "NICK " << newnick << " " << Anope::CurTime;
}

void IRCDProto::SendForceNickChange(User *u, const Anope::string &newnick, time_t when)
{
	UplinkSocket::Message() << "SVSNICK " << u->GetUID() << " " << newnick << " " << when;
}

void IRCDProto::SendCTCP(const MessageSource &source, const Anope::string &dest, const char *fmt, ...)
{
	va_list args;
	char buf[BUFSIZE] = "";
	va_start(args, fmt);
	vsnprintf(buf, BUFSIZE - 1, fmt, args);
	va_end(args);
	SendCTCPInternal(source, dest, buf);
}

void IRCDProto::SendNumeric(int numeric, const Anope::string &dest, const char *fmt, ...)
{
	va_list args;
	char buf[BUFSIZE] = "";
	va_start(args, fmt);
	vsnprintf(buf, BUFSIZE - 1, fmt, args);
	va_end(args);
	SendNumericInternal(numeric, dest, buf);
}

bool IRCDProto::IsNickValid(const Anope::string &nick)
{
	/**
	 * RFC: definition of a valid nick
	 * nickname =  ( letter / special ) ( letter / digit / special / "-" )
	 * letter   =  A-Z / a-z
	 * digit    =  0-9
	 * special  =  [, ], \, `, _, ^, {, |, }
	 **/

	 if (nick.empty())
		return false;

	Anope::string special = "[]\\`_^{|}";

	for (unsigned i = 0; i < nick.length(); ++i)
		if (!(nick[i] >= 'A' && nick[i] <= 'Z') && !(nick[i] >= 'a' && nick[i] <= 'z')
		  && special.find(nick[i]) == Anope::string::npos
		  && (Config && Config->NickChars.find(nick[i]) == Anope::string::npos)
		  && (!i || (!(nick[i] >= '0' && nick[i] <= '9') && nick[i] != '-')))
			return false;

	return true;
}

bool IRCDProto::IsChannelValid(const Anope::string &chan)
{
	if (chan.empty() || chan[0] != '#' || chan.length() > Config->GetBlock("networkinfo")->Get<unsigned>("chanlen"))
		return false;

	if (chan.find_first_of(" ,") != Anope::string::npos)
		return false;

	return true;
}

bool IRCDProto::IsIdentValid(const Anope::string &ident)
{
	if (ident.empty() || ident.length() > Config->GetBlock("networkinfo")->Get<unsigned>("userlen"))
		return false;

	for (unsigned i = 0; i < ident.length(); ++i)
	{
		const char &c = ident[i];

		if ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') || (c >= '0' && c <= '9') || c == '.' || c == '-')
			continue;

		return false;
	}

	return true;
}

bool IRCDProto::IsHostValid(const Anope::string &host)
{
	if (host.empty() || host.length() > Config->GetBlock("networkinfo")->Get<unsigned>("hostlen"))
		return false;

	const Anope::string &vhostdisablebe = Config->GetBlock("networkinfo")->Get<const Anope::string>("disallow_start_or_end"),
		vhostchars = Config->GetBlock("networkinfo")->Get<const Anope::string>("vhost_chars");

	if (vhostdisablebe.find_first_of(host[0]) != Anope::string::npos)
		return false;
	else if (vhostdisablebe.find_first_of(host[host.length() - 1]) != Anope::string::npos)
		return false;

	int dots = 0;
	for (unsigned i = 0; i < host.length(); ++i)
	{
		if (host[i] == '.')
			++dots;
		if (vhostchars.find_first_of(host[i]) == Anope::string::npos)
			return false;
	}

	return dots > 0 || Config->GetBlock("networkinfo")->Get<bool>("allow_undotted_vhosts");
}

void IRCDProto::SendOper(User *u)
{
	SendNumericInternal(381, u->GetUID(), ":You are now an IRC operator (set by services)");
	u->SetMode(NULL, "OPER");
}

unsigned IRCDProto::GetMaxListFor(Channel *c)
{
	return c->HasMode("LBAN") ? 0 : Config->GetBlock("networkinfo")->Get<int>("modelistsize");
}

unsigned IRCDProto::GetMaxListFor(Channel *c, ChannelMode *cm)
{
	return GetMaxListFor(c);
}

Anope::string IRCDProto::NormalizeMask(const Anope::string &mask)
{
	if (IsExtbanValid(mask))
		return mask;
	return Entry("", mask).GetNUHMask();
}

MessageSource::MessageSource(const Anope::string &src) : source(src), u(NULL), s(NULL)
{
	/* no source for incoming message is our uplink */
	if (src.empty())
		this->s = Servers::GetUplink();
	else if (IRCD->RequiresID || src.find('.') != Anope::string::npos)
		this->s = Server::Find(src);
	if (this->s == NULL)
		this->u = User::Find(src);
}

MessageSource::MessageSource(User *_u) : source(_u ? _u->nick : ""), u(_u), s(NULL)
{
}

MessageSource::MessageSource(Server *_s) : source(_s ? _s->GetName() : ""), u(NULL), s(_s)
{
}

const Anope::string &MessageSource::GetName() const
{
	if (this->s)
		return this->s->GetName();
	else if (this->u)
		return this->u->nick;
	else
		return this->source;
}

const Anope::string &MessageSource::GetSource() const
{
	return this->source;
}

User *MessageSource::GetUser() const
{
	return this->u;
}

BotInfo *MessageSource::GetBot() const
{
	return BotInfo::Find(this->GetName(), true);
}

Server *MessageSource::GetServer() const
{
	return this->s;
}

IRCDMessage::IRCDMessage(Module *o, const Anope::string &n, unsigned p) : Service(o, "IRCDMessage", o->name + "/" + n.lower()), name(n), param_count(p)
{
}

unsigned IRCDMessage::GetParamCount() const
{
	return this->param_count;
}

void IRCDMessage::Run(MessageSource &source, const std::vector<Anope::string> &params, const Anope::map<Anope::string> &tags)
{
	// Most IRCds don't support message tags yet so use the tagless variant.
	Run(source, params);
}