/* ChanServ core functions
 *
 * (C) 2003-2025 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 "module.h"
#include "modules/chanserv/mode.h"

class CommandCSSetKeepTopic final
	: public Command
{
public:
	CommandCSSetKeepTopic(Module *creator, const Anope::string &cname = "chanserv/set/keeptopic") : Command(creator, cname, 2, 2)
	{
		this->SetDesc(_("Retain topic when channel is not in use"));
		this->SetSyntax(_("\037channel\037 {ON | OFF}"));
	}

	void Execute(CommandSource &source, const std::vector<Anope::string> &params) override
	{
		if (Anope::ReadOnly)
		{
			source.Reply(READ_ONLY_MODE);
			return;
		}

		ChannelInfo *ci = ChannelInfo::Find(params[0]);
		if (ci == NULL)
		{
			source.Reply(CHAN_X_NOT_REGISTERED, params[0].c_str());
			return;
		}

		EventReturn MOD_RESULT;
		FOREACH_RESULT(OnSetChannelOption, MOD_RESULT, (source, this, ci, params[1]));
		if (MOD_RESULT == EVENT_STOP)
			return;

		if (MOD_RESULT != EVENT_ALLOW && !source.AccessFor(ci).HasPriv("SET") && source.permission.empty() && !source.HasPriv("chanserv/administration"))
		{
			source.Reply(ACCESS_DENIED);
			return;
		}

		if (params[1].equals_ci("ON"))
		{
			Log(source.AccessFor(ci).HasPriv("SET") ? LOG_COMMAND : LOG_OVERRIDE, source, this, ci) << "to enable keeptopic";
			ci->Extend<bool>("KEEPTOPIC");
			source.Reply(_("Topic retention option for %s is now \002on\002."), ci->name.c_str());
		}
		else if (params[1].equals_ci("OFF"))
		{
			Log(source.AccessFor(ci).HasPriv("SET") ? LOG_COMMAND : LOG_OVERRIDE, source, this, ci) << "to disable keeptopic";
			ci->Shrink<bool>("KEEPTOPIC");
			source.Reply(_("Topic retention option for %s is now \002off\002."), ci->name.c_str());
		}
		else
			this->OnSyntaxError(source, "KEEPTOPIC");
	}

	bool OnHelp(CommandSource &source, const Anope::string &) override
	{
		this->SendSyntax(source);
		source.Reply(" ");
		source.Reply(_(
				"Enables or disables the \002topic retention\002 option for a "
				"channel. When \002%s\002 is set, the topic for the "
				"channel will be remembered by %s even after the "
				"last user leaves the channel, and will be restored the "
				"next time the channel is created."
			),
			source.command.nobreak().c_str(),
			source.service->nick.c_str());
		return true;
	}
};

class CommandCSTopic final
	: public Command
{
	ExtensibleRef<bool> topiclock;

	void Lock(CommandSource &source, ChannelInfo *ci, const std::vector<Anope::string> &params)
	{
		if (Anope::ReadOnly)
		{
			source.Reply(READ_ONLY_MODE);
			return;
		}

		EventReturn MOD_RESULT;
		FOREACH_RESULT(OnSetChannelOption, MOD_RESULT, (source, this, ci, "topiclock on"));
		if (MOD_RESULT == EVENT_STOP)
			return;

		topiclock->Set(ci, true);
		source.Reply(_("Topic lock option for %s is now \002on\002."), ci->name.c_str());
	}

	void Unlock(CommandSource &source, ChannelInfo *ci, const std::vector<Anope::string> &params)
	{
		if (Anope::ReadOnly)
		{
			source.Reply(READ_ONLY_MODE);
			return;
		}

		EventReturn MOD_RESULT;
		FOREACH_RESULT(OnSetChannelOption, MOD_RESULT, (source, this, ci, "topiclock off"));
		if (MOD_RESULT == EVENT_STOP)
			return;

		topiclock->Unset(ci);
		source.Reply(_("Topic lock option for %s is now \002off\002."), ci->name.c_str());
	}

	void Set(CommandSource &source, ChannelInfo *ci, const Anope::string &topic)
	{
		bool has_topiclock = topiclock->HasExt(ci);
		topiclock->Unset(ci);
		ci->c->ChangeTopic(source.GetNick(), topic, Anope::CurTime);
		if (has_topiclock)
			topiclock->Set(ci);

		bool override = !source.AccessFor(ci).HasPriv("TOPIC");
		Log(override ? LOG_OVERRIDE : LOG_COMMAND, source, this, ci) << (!topic.empty() ? "to change the topic to: " : "to unset the topic") << (!topic.empty() ? topic : "");
	}

	void Append(CommandSource &source, ChannelInfo *ci, const std::vector<Anope::string> &params)
	{
		const Anope::string &topic = params[2];

		Anope::string new_topic;
		if (!ci->c->topic.empty())
		{
			new_topic = ci->c->topic + " " + topic;
			ci->last_topic.clear();
		}
		else
			new_topic = topic;

		this->Set(source, ci, new_topic);
	}

public:
	CommandCSTopic(Module *creator) : Command(creator, "chanserv/topic", 2, 3),
		topiclock("TOPICLOCK")
	{
		this->SetDesc(_("Manipulate the topic of the specified channel"));
		this->SetSyntax(_("\037channel\037 [SET] [\037topic\037]"));
		this->SetSyntax(_("\037channel\037 APPEND \037topic\037"));
		this->SetSyntax(_("\037channel\037 [UNLOCK|LOCK]"));
	}

	void Execute(CommandSource &source, const std::vector<Anope::string> &params) override
	{
		const Anope::string &subcmd = params[1];

		ChannelInfo *ci = ChannelInfo::Find(params[0]);
		if (ci == NULL)
			source.Reply(CHAN_X_NOT_REGISTERED, params[0].c_str());
		else if (!source.AccessFor(ci).HasPriv("TOPIC") && !source.HasCommand("chanserv/topic"))
			source.Reply(ACCESS_DENIED);
		else if (subcmd.equals_ci("LOCK"))
			this->Lock(source, ci, params);
		else if (subcmd.equals_ci("UNLOCK"))
			this->Unlock(source, ci, params);
		else if (!ci->c)
			source.Reply(CHAN_X_NOT_IN_USE, ci->name.c_str());
		else if (subcmd.equals_ci("APPEND") && params.size() > 2)
			this->Append(source, ci, params);
		else
		{
			Anope::string topic;
			if (subcmd.equals_ci("SET"))
			{
				topic = params.size() > 2 ? params[2] : "";
			}
			else
			{
				topic = subcmd;
				if (params.size() > 2)
					topic += " " + params[2];
			}
			this->Set(source, ci, topic);
		}
	}

	bool OnHelp(CommandSource &source, const Anope::string &subcommand) override
	{
		this->SendSyntax(source);
		source.Reply(" ");
		source.Reply(_(
			"Allows manipulating the topic of the specified channel. "
			"The \002SET\002 command changes the topic of the channel to the given topic "
			"or unsets the topic if no topic is given. The \002APPEND\002 command appends "
			"the given topic to the existing topic. "
			"\n\n"
			"\002LOCK\002 and \002UNLOCK\002 may be used to enable and disable topic lock. When "
			"topic lock is set, the channel topic will be unchangeable by users who do not have "
			"the \002TOPIC\002 privilege."
		));
		return true;
	}
};

class CSTopic final
	: public Module
{
	CommandCSTopic commandcstopic;
	CommandCSSetKeepTopic commandcssetkeeptopic;

	SerializableExtensibleItem<bool> topiclock, keeptopic;

public:
	CSTopic(const Anope::string &modname, const Anope::string &creator) : Module(modname, creator, VENDOR),
		commandcstopic(this), commandcssetkeeptopic(this), topiclock(this, "TOPICLOCK"), keeptopic(this, "KEEPTOPIC")
	{

	}

	void OnChannelSync(Channel *c) override
	{
		if (c->ci)
		{
			/* Update channel topic */
			if ((topiclock.HasExt(c->ci) || keeptopic.HasExt(c->ci)) && c->ci->last_topic != c->topic)
			{
				c->ChangeTopic(!c->ci->last_topic_setter.empty() ? c->ci->last_topic_setter : c->ci->WhoSends()->nick, c->ci->last_topic, c->ci->last_topic_time ? c->ci->last_topic_time : Anope::CurTime);
			}
		}
	}

	void OnTopicUpdated(User *source, Channel *c, const Anope::string &user, const Anope::string &topic) override
	{
		if (!c->ci)
			return;

		/* We only compare the topics here, not the time or setter. This is because some (old) IRCds do not
		 * allow us to set the topic as someone else, meaning we have to bump the TS and change the setter to us.
		 * This desyncs what is really set with what we have stored, and we end up resetting the topic often when
		 * it is not required
		 */
		if (topiclock.HasExt(c->ci) && c->ci->last_topic != c->topic && (!source || !c->ci->AccessFor(source).HasPriv("TOPIC")))
		{
			c->ChangeTopic(c->ci->last_topic_setter, c->ci->last_topic, c->ci->last_topic_time);
		}
		else
		{
			c->ci->last_topic = c->topic;
			c->ci->last_topic_setter = c->topic_setter;
			c->ci->last_topic_time = c->topic_ts;
		}
	}

	void OnChanInfo(CommandSource &source, ChannelInfo *ci, InfoFormatter &info, bool show_all) override
	{
		if (keeptopic.HasExt(ci))
			info.AddOption(_("Topic retention"));
		if (topiclock.HasExt(ci))
			info.AddOption(_("Topic lock"));

		ModeLocks *ml = ci->GetExt<ModeLocks>("modelocks");
		const ModeLock *secret = ml ? ml->GetMLock("SECRET") : NULL;
		if (!ci->last_topic.empty() && (show_all || ((!secret || !secret->set) && (!ci->c || !ci->c->HasMode("SECRET")))))
		{
			info[_("Last topic")] = ci->last_topic;
			info[_("Topic set by")] = ci->last_topic_setter;
		}
	}
};

MODULE_INIT(CSTopic)