/* Modular support
 *
 * (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 "serialize.h"

#ifndef MODULES_H
#define MODULES_H

#include "base.h"
#include "modes.h"
#include "timers.h"
#include "logger.h"
#include "extensible.h"
#include "version.h"

/** This definition is used as shorthand for the various classes
 * and functions needed to make a module loadable by the OS.
 * It defines the class factory and external AnopeInit and AnopeFini functions.
 */
#ifdef _WIN32
# define MODULE_INIT(x) \
	extern "C" DllExport Module *AnopeInit(const Anope::string &, const Anope::string &); \
	extern "C" Module *AnopeInit(const Anope::string &modname, const Anope::string &creator) \
	{ \
		return new x(modname, creator); \
	} \
	BOOLEAN WINAPI DllMain(HINSTANCE, DWORD, LPVOID) \
	{ \
		return TRUE; \
	} \
	extern "C" DllExport void AnopeFini(x *); \
	extern "C" void AnopeFini(x *m) \
	{ \
		delete m; \
	} \
	extern "C" DllExport ModuleVersionC AnopeVersion() \
	{ \
		ModuleVersionC ver; \
		ver.version_major = VERSION_MAJOR; \
		ver.version_minor = VERSION_MINOR; \
		ver.version_patch = VERSION_PATCH; \
		return ver; \
	}
#else
# define MODULE_INIT(x) \
	extern "C" DllExport Module *AnopeInit(const Anope::string &modname, const Anope::string &creator) \
	{ \
		return new x(modname, creator); \
	} \
	extern "C" DllExport void AnopeFini(x *m) \
	{ \
		delete m; \
	} \
	extern "C" DllExport ModuleVersionC AnopeVersion() \
	{ \
		ModuleVersionC ver; \
		ver.version_major = VERSION_MAJOR; \
		ver.version_minor = VERSION_MINOR; \
		ver.version_patch = VERSION_PATCH; \
		return ver; \
	}
#endif

/**
 * This #define allows us to call a method in all
 * loaded modules in a readable simple way, e.g.:
 *
 * FOREACH_MOD(OnUserConnect, (user, exempt));
 */
#define FOREACH_MOD(ename, args) \
if (true) \
{ \
	std::vector<Module *> &_modules = ModuleManager::EventHandlers[I_ ## ename]; \
	for (std::vector<Module *>::iterator _i = _modules.begin(); _i != _modules.end();) \
	{ \
		try \
		{ \
			(*_i)->ename args; \
		} \
		catch (const ModuleException &modexcept) \
		{ \
			Log() << "Exception caught: " << modexcept.GetReason(); \
		} \
		catch (const NotImplementedException &) \
		{ \
			_i = _modules.erase(_i); \
			continue; \
		} \
		++_i; \
	} \
} \
else \
	static_cast<void>(0)

/**
 * This define is similar to the one above but returns a result.
 * The first module to return a result other than EVENT_CONTINUE is the value to be accepted,
 * and any modules after are ignored. This is used like:
 *
 * EventReturn MOD_RESULT;
 * FOREACH_RESULT(OnUserConnect, MOD_RESULT, (user, exempt));
 */
#define FOREACH_RESULT(ename, ret, args) \
if (true) \
{ \
	ret = EVENT_CONTINUE; \
	std::vector<Module *> &_modules = ModuleManager::EventHandlers[I_ ## ename]; \
	for (std::vector<Module *>::iterator _i = _modules.begin(); _i != _modules.end();) \
	{ \
		try \
		{ \
			EventReturn res = (*_i)->ename args; \
			if (res != EVENT_CONTINUE) \
			{ \
				ret = res; \
				break; \
			} \
		} \
		catch (const ModuleException &modexcept) \
		{ \
			Log() << "Exception caught: " << modexcept.GetReason(); \
		} \
		catch (const NotImplementedException &) \
		{ \
			_i = _modules.erase(_i); \
			continue; \
		} \
		++_i; \
	} \
} \
else \
	static_cast<void>(0)


/** Possible return types from events.
 */
enum EventReturn
{
	EVENT_STOP,
	EVENT_CONTINUE,
	EVENT_ALLOW
};

enum ModuleReturn
{
	MOD_ERR_OK,
	MOD_ERR_PARAMS,
	MOD_ERR_EXISTS,
	MOD_ERR_NOEXIST,
	MOD_ERR_NOLOAD,
	MOD_ERR_UNKNOWN,
	MOD_ERR_FILE_IO,
	MOD_ERR_EXCEPTION,
	MOD_ERR_VERSION
};

/** Priority types which can be returned from Module::Prioritize()
 */
enum Priority { PRIORITY_FIRST, PRIORITY_DONTCARE, PRIORITY_LAST, PRIORITY_BEFORE, PRIORITY_AFTER };
/* Module types, in the order in which they are unloaded. The order these are in is IMPORTANT */
enum
{
	MT_BEGIN,
	/* Module is 3rd party. All 3rd party modules should set this. Mutually exclusive to VENDOR. */
	THIRD = 1 << 0,
	/* A vendor module, which is made and shipped by Anope. Mutually exclusive to THIRD. */
	VENDOR = 1 << 1,
	/* Extra module not required for standard use. Probably requires external dependencies.
	 * This module does something extreme enough that we want it to show in the default /os modlist command
	 */
	EXTRA = 1 << 2,
	/* Module provides access to a database */
	DATABASE = 1 << 3,
	/* Module provides encryption */
	ENCRYPTION = 1 << 4,
	/* Module provides a pseudoclient */
	PSEUDOCLIENT = 1 << 5,
	/* Module provides IRCd protocol support */
	PROTOCOL = 1 << 6,
	MT_END = 1 << 7
};
typedef unsigned short ModType;

struct ModuleVersionC
{
	int version_major, version_minor, version_patch;
};

/** Returned by Module::GetVersion, used to see what version of Anope
 * a module is compiled against.
 */
class ModuleVersion
{
 private:
	int version_major;
	int version_minor;
	int version_patch;

 public:
	ModuleVersion(const ModuleVersionC &);

	/** Get the major version of Anope this was built against
	 * @return The major version
	 */
	int GetMajor() const;

	/** Get the minor version of Anope this was built against
	 * @return The minor version
	 */
	int GetMinor() const;

	/** Get the patch version this was built against
	 * @return The patch version
	 */
	int GetPatch() const;
};

class NotImplementedException : public CoreException { };

/** Every module in Anope is actually a class.
 */
class CoreExport Module : public Extensible
{
 private:
	bool permanent;
 public:
	/** The module name (e.g. os_modload)
	 */
	Anope::string name;

	/** What type this module is
	 */
	ModType type;

	/** The temporary path/filename
	 */
	Anope::string filename;

	/** Handle for this module, obtained from dlopen()
	 */
	void *handle;

	/** Time this module was created
	 */
	time_t created;

	/** Version of this module
	 */
	Anope::string version;

	/** Author of the module
	 */
	Anope::string author;

	/** Creates and initialises a new module.
	 * @param modname The module name
	 * @param loadernick The nickname of the user loading the module.
	 * @param type The module type
	 */
	Module(const Anope::string &modname, const Anope::string &loadernick, ModType type = THIRD);

	/** Destroys a module, freeing resources it has allocated.
	 */
	virtual ~Module();

	/** Toggles the permanent flag on a module. If a module is permanent,
	 * then it may not be unloaded.
	 *
	 * Naturally, this setting should be used sparingly!
	 *
	 * @param state True if this module should be permanent, false else.
	 */
	void SetPermanent(bool state);

	/** Retrieves whether or not a given module is permanent.
	 * @return true if the module is permanent, false else.
	 */
	bool GetPermanent() const;

	/** Set the modules version info.
	 * @param version the version of the module
	 */
	void SetVersion(const Anope::string &version);

	/** Set the modules author info
	 * @param author the author of the module
	 */
	void SetAuthor(const Anope::string &author);

	virtual void Prioritize();

	/* Everything below here are events. Modules must ModuleManager::Attach to these events
	 * before they will be called.
	 */

	/** Called on startup after database load, but before
	 * connecting to the uplink.
	 */
	virtual void OnPostInit() { throw NotImplementedException(); }

	/** Called before a user has been kicked from a channel.
	 * @param source The kicker
	 * @param cu The user, channel, and status of the user being kicked
	 * @param kickmsg The reason for the kick.
	 */
	virtual void OnPreUserKicked(const MessageSource &source, ChanUserContainer *cu, const Anope::string &kickmsg) { throw NotImplementedException(); }

	/** Called when a user has been kicked from a channel.
	 * @param source The kicker
	 * @param target The user being kicked
	 * @param channel The channel the user was kicked from, which may no longer exist
	 * @param status The status the kicked user had on the channel before they were kicked
	 * @param kickmsg The reason for the kick.
	 */
	virtual void OnUserKicked(const MessageSource &source, User *target, const Anope::string &channel, ChannelStatus &status, const Anope::string &kickmsg) { throw NotImplementedException(); }

	/** Called when Services' configuration is being (re)loaded.
	 * @param conf The config that is being built now and will replace the global Config object
	 * @throws A ConfigException to abort the config (re)loading process.
	 */
	virtual void OnReload(Configuration::Conf *conf) { throw NotImplementedException(); }

	/** Called before a bot is assigned to a channel.
	 * @param sender The user assigning the bot
	 * @param ci The channel the bot is to be assigned to.
	 * @param bi The bot being assigned.
	 * @return EVENT_CONTINUE to let other modules decide, EVENT_STOP to deny the assign.
	 */
	virtual EventReturn OnPreBotAssign(User *sender, ChannelInfo *ci, BotInfo *bi) { throw NotImplementedException(); }

	/** Called when a bot is assigned ot a channel
	 */
	virtual void OnBotAssign(User *sender, ChannelInfo *ci, BotInfo *bi) { throw NotImplementedException(); }

	/** Called before a bot is unassigned from a channel.
	 * @param sender The user unassigning the bot
	 * @param ci The channel the bot is being removed from
	 * @return EVENT_CONTINUE to let other modules decide, EVENT_STOP to deny the unassign.
	 */
	virtual EventReturn OnBotUnAssign(User *sender, ChannelInfo *ci) { throw NotImplementedException(); }

	/** Called when a new user connects to the network.
	 * @param u The connecting user.
	 * @param exempt set to true/is true if the user should be excepted from bans etc
	 */
	virtual void OnUserConnect(User *u, bool &exempt) { throw NotImplementedException(); }

	/** Called when a new server connects to the network.
	 * @param s The server that has connected to the network
	 */
	virtual void OnNewServer(Server *s) { throw NotImplementedException(); }

	/** Called after a user changed the nick
	 * @param u The user.
	 * @param oldnick The old nick of the user
	 */
	virtual void OnUserNickChange(User *u, const Anope::string &oldnick) { throw NotImplementedException(); }

	/** Called when someone uses the generic/help command
	 * @param source Command source
	 * @param params Params
	 * @return EVENT_STOP to stop processing
	 */
	virtual EventReturn OnPreHelp(CommandSource &source, const std::vector<Anope::string> &params) { throw NotImplementedException(); }

	/** Called when someone uses the generic/help command
	 * @param source Command source
	 * @param params Params
	 */
	virtual void OnPostHelp(CommandSource &source, const std::vector<Anope::string> &params) { throw NotImplementedException(); }

	/** Called before a command is due to be executed.
	 * @param source The source of the command
	 * @param command The command the user is executing
	 * @param params The parameters the user is sending
	 * @return EVENT_CONTINUE to let other modules decide, EVENT_STOP to halt the command and not process it
	 */
	virtual EventReturn OnPreCommand(CommandSource &source, Command *command, std::vector<Anope::string> &params) { throw NotImplementedException(); }

	/** Called after a command has been executed.
	 * @param source The source of the command
	 * @param command The command the user executed
	 * @param params The parameters the user sent
	 */
	virtual void OnPostCommand(CommandSource &source, Command *command, const std::vector<Anope::string> &params) { throw NotImplementedException(); }

	/** Called when the databases are saved
	 */
	virtual void OnSaveDatabase() { throw NotImplementedException(); }

	/** Called when the databases are loaded
	 * @return EVENT_CONTINUE to let other modules continue loading, EVENT_STOP to stop
	 */
	virtual EventReturn OnLoadDatabase() { throw NotImplementedException(); }

	/** Called when anope needs to check passwords against encryption
	 *  see src/encrypt.c for detailed informations
	 */
	virtual EventReturn OnEncrypt(const Anope::string &src, Anope::string &dest) { throw NotImplementedException(); }
	virtual EventReturn OnDecrypt(const Anope::string &hashm, const Anope::string &src, Anope::string &dest) { throw NotImplementedException(); }

	/** Called on fantasy command
	 * @param source The source of the command
	 * @param c The command
	 * @param ci The channel it's being used in
	 * @param params The params
	 * @return EVENT_STOP to halt processing and not run the command, EVENT_ALLOW to allow the command to be executed
	 */
	virtual EventReturn OnBotFantasy(CommandSource &source, Command *c, ChannelInfo *ci, const std::vector<Anope::string> &params) { throw NotImplementedException(); }

	/** Called on fantasy command without access
	 * @param source The source of the command
	 * @param c The command
	 * @param ci The channel it's being used in
	 * @param params The params
	 * @return EVENT_STOP to halt processing and not run the command, EVENT_ALLOW to allow the command to be executed
	 */
	virtual EventReturn OnBotNoFantasyAccess(CommandSource &source, Command *c, ChannelInfo *ci, const std::vector<Anope::string> &params) { throw NotImplementedException(); }

	/** Called when a bot places a ban
	 * @param u User being banned
	 * @param ci Channel the ban is placed on
	 * @param mask The mask being banned
	 */
	virtual void OnBotBan(User *u, ChannelInfo *ci, const Anope::string &mask) { throw NotImplementedException(); }

	/** Called before a badword is added to the badword list
	 * @param ci The channel
	 * @param bw The badword
	 */
	virtual void OnBadWordAdd(ChannelInfo *ci, const BadWord *bw) { throw NotImplementedException(); }

	/** Called before a badword is deleted from a channel
	 * @param ci The channel
	 * @param bw The badword
	 */
	virtual void OnBadWordDel(ChannelInfo *ci, const BadWord *bw) { throw NotImplementedException(); }

	/** Called when a bot is created or destroyed
	 */
	virtual void OnCreateBot(BotInfo *bi) { throw NotImplementedException(); }
	virtual void OnDelBot(BotInfo *bi) { throw NotImplementedException(); }

	/** Called before a bot kicks a user
	 * @param bi The bot sending the kick
	 * @param c The channel the user is being kicked on
	 * @param u The user being kicked
	 * @param reason The reason
	 * @return EVENT_CONTINUE to let other modules decide, EVENT_STOP to halt the command and not process it
	 */
	virtual EventReturn OnBotKick(BotInfo *bi, Channel *c, User *u, const Anope::string &reason) { throw NotImplementedException(); }

	/** Called before a user parts a channel
	 * @param u The user
	 * @param c The channel
	 */
	virtual void OnPrePartChannel(User *u, Channel *c) {}

	/** Called when a user parts a channel
	 * @param u The user
	 * @param c The channel, may be NULL if the channel no longer exists
	 * @param channel The channel name
	 * @param msg The part reason
	 */
	virtual void OnPartChannel(User *u, Channel *c, const Anope::string &channel, const Anope::string &msg) { throw NotImplementedException(); }

	/** Called when a user leaves a channel.
	 * From either parting, being kicked, or quitting/killed!
	 * @param u The user
	 * @param c The channel
	 */
	virtual void OnLeaveChannel(User *u, Channel *c) { throw NotImplementedException(); }

	/** Called after a user joins a channel
	 * If this event triggers the user is allowed to be in the channel, and will
	 * not be kicked for restricted/akick/forbidden, etc. If you want to kick the user,
	 * use the CheckKick event instead.
	 * @param u The user
	 * @param channel The channel
	 */
	virtual void OnJoinChannel(User *u, Channel *c) { throw NotImplementedException(); }

	/** Called when a new topic is set
	 * @param source The user changing the topic, if any
	 * @param c The channel
	 * @param setter The user who set the new topic, if there is no source
	 * @param topic The new topic
	 */
	virtual void OnTopicUpdated(User *source, Channel *c, const Anope::string &user, const Anope::string &topic) { throw NotImplementedException(); }

	/** Called before a channel expires
	 * @param ci The channel
	 * @param expire Set to true to allow the chan to expire
	 */
	virtual void OnPreChanExpire(ChannelInfo *ci, bool &expire) { throw NotImplementedException(); }

	/** Called before a channel expires
	 * @param ci The channel
	 */
	virtual void OnChanExpire(ChannelInfo *ci) { throw NotImplementedException(); }

	/** Called before Anope connects to its uplink
	 */
	virtual void OnPreServerConnect() { throw NotImplementedException(); }

	/** Called when Anope connects to its uplink
	 */
	virtual void OnServerConnect() { throw NotImplementedException(); }

	/** Called when we are almost done synching with the uplink, just before we send the EOB
	 */
	virtual void OnPreUplinkSync(Server *serv) { throw NotImplementedException(); }

	/** Called when Anope disconnects from its uplink, before it tries to reconnect
	 */
	virtual void OnServerDisconnect() { throw NotImplementedException(); }

	/** Called when services restart
	*/
	virtual void OnRestart() { throw NotImplementedException(); }

	/** Called when services shutdown
	 */
	virtual void OnShutdown() { throw NotImplementedException(); }

	/** Called before a nick expires
	 * @param na The nick
	 * @param expire Set to true to allow the nick to expire
	 */
	virtual void OnPreNickExpire(NickAlias *na, bool &expire) { throw NotImplementedException(); }

	/** Called when a nick drops
	 * @param na The nick
	 */
	virtual void OnNickExpire(NickAlias *na) { throw NotImplementedException(); }

	/** Called when defcon level changes
	 * @param level The level
	 */
	virtual void OnDefconLevel(int level) { throw NotImplementedException(); }

	/** Called after an exception has been added
	 * @param ex The exception
	 * @return EVENT_CONTINUE to let other modules decide, EVENT_STOP to halt the command and not process it
	 */
	virtual EventReturn OnExceptionAdd(Exception *ex) { throw NotImplementedException(); }

	/** Called before an exception is deleted
	 * @param source The source deleting it
	 * @param ex The exception
	 */
	virtual void OnExceptionDel(CommandSource &source, Exception *ex) { throw NotImplementedException(); }

	/** Called before a XLine is added
	 * @param source The source of the XLine
	 * @param x The XLine
	 * @param xlm The xline manager it was added to
	 * @return EVENT_CONTINUE to let other modules decide, EVENT_STOP to halt the command and not process it
	 */
	virtual EventReturn OnAddXLine(CommandSource &source, const XLine *x, XLineManager *xlm) { throw NotImplementedException(); }

	/** Called before a XLine is deleted
	 * @param source The source of the XLine
	 * @param x The XLine
	 * @param xlm The xline manager it was deleted from
	 */
	virtual void OnDelXLine(CommandSource &source, const XLine *x, XLineManager *xlm) { throw NotImplementedException(); }

	/** Called when a user is checked for whether they are a services oper
	 * @param u The user
	 * @return EVENT_ALLOW to allow, anything else to deny
	 */
	virtual EventReturn IsServicesOper(User *u) { throw NotImplementedException(); }

	/** Called when a server quits
	 * @param server The server
	 */
	virtual void OnServerQuit(Server *server) { throw NotImplementedException(); }

	/** Called when a user quits, or is killed
	 * @param u The user
	 * @param msg The quit message
	 */
	virtual void OnUserQuit(User *u, const Anope::string &msg) { throw NotImplementedException(); }

	/** Called when a user is quit, before and after being internally removed from
	 * This is different from OnUserQuit, which takes place at the time of the quit.
	 * This happens shortly after when all message processing is finished.
	 * all lists (channels, user list, etc)
	 * @param u The user
	 */
	virtual void OnPreUserLogoff(User *u) { throw NotImplementedException(); }
	virtual void OnPostUserLogoff(User *u) { throw NotImplementedException(); }

	/** Called when a new bot is made
	 * @param bi The bot
	 */
	virtual void OnBotCreate(BotInfo *bi) { throw NotImplementedException(); }

	/** Called when a bot is changed
	 * @param bi The bot
	 */
	virtual void OnBotChange(BotInfo *bi) { throw NotImplementedException(); }

	/** Called when a bot is deleted
	 * @param bi The bot
	 */
	virtual void OnBotDelete(BotInfo *bi) { throw NotImplementedException(); }

	/** Called after an access entry is deleted from a channel
	 * @param ci The channel
	 * @param source The source of the command
	 * @param access The access entry that was removed
	 */
	virtual void OnAccessDel(ChannelInfo *ci, CommandSource &source, ChanAccess *access) { throw NotImplementedException(); }

	/** Called when access is added
	 * @param ci The channel
	 * @param source The source of the command
	 * @param access The access changed
	 */
	virtual void OnAccessAdd(ChannelInfo *ci, CommandSource &source, ChanAccess *access) { throw NotImplementedException(); }

	/** Called when the access list is cleared
	 * @param ci The channel
	 * @param u The user who cleared the access
	 */
	virtual void OnAccessClear(ChannelInfo *ci, CommandSource &source) { throw NotImplementedException(); }

	/** Called when a level for a channel is changed
	 * @param source The source of the command
	 * @param ci The channel the level was changed on
	 * @param priv The privilege changed
	 * @param what The new level
	 */
	virtual void OnLevelChange(CommandSource &source, ChannelInfo *ci, const Anope::string &priv, int16_t what) { throw NotImplementedException(); }

	/** Called right before a channel is dropped
	 * @param source The user dropping the channel
	 * @param ci The channel
	 */
	virtual EventReturn OnChanDrop(CommandSource &source, ChannelInfo *ci) { throw NotImplementedException(); }

	/** Called when a channel is registered
	 * @param ci The channel
	 */
	virtual void OnChanRegistered(ChannelInfo *ci) { throw NotImplementedException(); }

	/** Called when a channel is suspended
	 * @param ci The channel
	 */
	virtual void OnChanSuspend(ChannelInfo *ci) { throw NotImplementedException(); }

	/** Called when a channel is unsuspended
	 * @param ci The channel
	 */
	virtual void OnChanUnsuspend(ChannelInfo *ci) { throw NotImplementedException(); }

	/** Called when a channel is being created, for any reason
	 * @param ci The channel
	 */
	virtual void OnCreateChan(ChannelInfo *ci) { throw NotImplementedException(); }

	/** Called when a channel is being deleted, for any reason
	 * @param ci The channel
	 */
	virtual void OnDelChan(ChannelInfo *ci) { throw NotImplementedException(); }

	/** Called when a new channel is created
	 * Note that this channel may not be introduced to the uplink at this point.
	 * @param c The channel
	 */
	virtual void OnChannelCreate(Channel *c) { throw NotImplementedException(); }

	/** Called when a channel is deleted
	 * @param c The channel
	 */
	virtual void OnChannelDelete(Channel *c) { throw NotImplementedException(); }

	/** Called after adding an akick to a channel
	 * @param source The source of the command
	 * @param ci The channel
	 * @param ak The akick
	 */
	virtual void OnAkickAdd(CommandSource &source, ChannelInfo *ci, const AutoKick *ak) { throw NotImplementedException(); }

	/** Called before removing an akick from a channel
	 * @param source The source of the command
	 * @param ci The channel
	 * @param ak The akick
	 */
	virtual void OnAkickDel(CommandSource &source, ChannelInfo *ci, const AutoKick *ak) { throw NotImplementedException(); }

	/** Called after a user join a channel when we decide whether to kick them or not
	 * @param u The user
	 * @param c The channel
	 * @param kick Set to true to kick
	 * @param mask The mask to ban, if any
	 * @param reason The reason for the kick
	 * @return EVENT_STOP to prevent the user from joining by kicking/banning the user
	 */
	virtual EventReturn OnCheckKick(User *u, Channel *c, Anope::string &mask, Anope::string &reason) { throw NotImplementedException(); }

	/** Called when a user requests info for a channel
	 * @param source The user requesting info
	 * @param ci The channel the user is requesting info for
	 * @param info Data to show the user requesting information
	 * @param show_hidden true if we should show the user everything
	 */
	virtual void OnChanInfo(CommandSource &source, ChannelInfo *ci, InfoFormatter &info, bool show_hidden) { throw NotImplementedException(); }

	/** Checks if access has the channel privilege 'priv'.
	 * @param access THe access struct
	 * @param priv The privilege being checked for
	 * @return EVENT_ALLOW for yes, EVENT_STOP to stop all processing
	 */
	virtual EventReturn OnCheckPriv(const ChanAccess *access, const Anope::string &priv) { throw NotImplementedException(); }

	/** Check whether an access group has a privilege
	 * @param group The group
	 * @param priv The privilege
	 * @return MOD_ALLOW to allow, MOD_STOP to stop
	 */
	virtual EventReturn OnGroupCheckPriv(const AccessGroup *group, const Anope::string &priv) { throw NotImplementedException(); }

	/** Called when a nick is dropped
	 * @param source The source of the command
	 * @param na The nick
	 */
	virtual void OnNickDrop(CommandSource &source, NickAlias *na) { throw NotImplementedException(); }

	/** Called when a user groups their nick
	 * @param u The user grouping
	 * @param target The target they're grouping to
	 */
	virtual void OnNickGroup(User *u, NickAlias *target) { throw NotImplementedException(); }

	/** Called when a user identifies to a nick
	 * @param u The user
	 */
	virtual void OnNickIdentify(User *u) { throw NotImplementedException(); }

	/** Called when a user is logged into an account
	 * @param u The user
	 */
	virtual void OnUserLogin(User *u) { throw NotImplementedException(); }

	/** Called when a nick logs out
	 * @param u The nick
	 */
	virtual void OnNickLogout(User *u) { throw NotImplementedException(); }

	/** Called when a nick is registered
	 * @param user The user registering the nick, of any
	 * @param The nick
	 * @param pass The password of the newly registered nick
	 */
	virtual void OnNickRegister(User *user, NickAlias *na, const Anope::string &pass) { throw NotImplementedException(); }

	/** Called when a nick is confirmed. This will never be called if registration confirmation is not enabled.
	 * @param user The user confirming the nick
	 * @param The account being confirmed
	 */
	virtual void OnNickConfirm(User *user, NickCore *) { throw NotImplementedException(); }

	/** Called when a nick is suspended
	 * @param na The nick alias
	 */
	virtual void OnNickSuspend(NickAlias *na) { throw NotImplementedException(); }

	/** Called when a nick is unsuspended
	 * @param na The nick alias
	 */
	virtual void OnNickUnsuspended(NickAlias *na) { throw NotImplementedException(); }

	/** Called on delnick()
	 * @ param na pointer to the nickalias
	 */
	virtual void OnDelNick(NickAlias *na) { throw NotImplementedException(); }

	/** Called when a nickcore is created
	 * @param nc The nickcore
	 */
	virtual void OnNickCoreCreate(NickCore *nc) { throw NotImplementedException(); }

	/** Called on delcore()
	 * @param nc pointer to the NickCore
	 */
	virtual void OnDelCore(NickCore *nc) { throw NotImplementedException(); }

	/** Called on change_core_display()
	 * @param nc pointer to the NickCore
	 * @param newdisplay the new display
	 */
	virtual void OnChangeCoreDisplay(NickCore *nc, const Anope::string &newdisplay) { throw NotImplementedException(); }

	/** called from NickCore::ClearAccess()
	 * @param nc pointer to the NickCore
	 */
	virtual void OnNickClearAccess(NickCore *nc) { throw NotImplementedException(); }

	/** Called when a user adds an entry to their access list
	 * @param nc The nick
	 * @param entry The entry
	 */
	virtual void OnNickAddAccess(NickCore *nc, const Anope::string &entry) { throw NotImplementedException(); }

	/** Called from NickCore::EraseAccess()
	 * @param nc pointer to the NickCore
	 * @param entry The access mask
	 */
	virtual void OnNickEraseAccess(NickCore *nc, const Anope::string &entry) { throw NotImplementedException(); }

	/** called from NickCore::ClearCert()
	 * @param nc pointer to the NickCore
	 */
	virtual void OnNickClearCert(NickCore *nc) { throw NotImplementedException(); }

	/** Called when a user adds an entry to their cert list
	 * @param nc The nick
	 * @param entry The entry
	 */
	virtual void OnNickAddCert(NickCore *nc, const Anope::string &entry) { throw NotImplementedException(); }

	/** Called from NickCore::EraseCert()
	 * @param nc pointer to the NickCore
	 * @param entry The fingerprint
	 */
	virtual void OnNickEraseCert(NickCore *nc, const Anope::string &entry) { throw NotImplementedException(); }

	/** Called when a user requests info for a nick
	 * @param source The user requesting info
	 * @param na The nick the user is requesting info from
	 * @param info Data to show the user requesting information
	 * @param show_hidden true if we should show the user everything
	 */
	virtual void OnNickInfo(CommandSource &source, NickAlias *na, InfoFormatter &info, bool show_hidden) { throw NotImplementedException(); }

	/** Called when a user uses botserv/info on a bot or channel.
	 */
	virtual void OnBotInfo(CommandSource &source, BotInfo *bi, ChannelInfo *ci, InfoFormatter &info) { throw NotImplementedException(); }

	/** Check whether a username and password is correct
	 * @param u The user trying to identify, if applicable.
	 * @param req The login request
	 */
	virtual void OnCheckAuthentication(User *u, IdentifyRequest *req) { throw NotImplementedException(); }

	/** Called when a user does /ns update
	 * @param u The user
	 */
	virtual void OnNickUpdate(User *u) { throw NotImplementedException(); }

	/** Called when we get informed about a users SSL fingerprint
	 *  when we call this, the fingerprint should already be stored in the user struct
	 * @param u pointer to the user
	 */
	virtual void OnFingerprint(User *u) { throw NotImplementedException(); }

	/** Called when a user becomes (un)away
	 * @param message The message, is .empty() if unaway
	 */
	virtual void OnUserAway(User *u, const Anope::string &message) { throw NotImplementedException(); }

	/** Called when a user invites one of our users to a channel
	 * @param source The user doing the inviting
	 * @param c The channel the user is inviting to
	 * @param targ The user being invited
	 */
	virtual void OnInvite(User *source, Channel *c, User *targ) { throw NotImplementedException(); }

	/** Called when a vhost is deleted
	 * @param na The nickalias of the vhost
	 */
	virtual void OnDeleteVhost(NickAlias *na) { throw NotImplementedException(); }

	/** Called when a vhost is set
	 * @param na The nickalias of the vhost
	 */
	virtual void OnSetVhost(NickAlias *na) { throw NotImplementedException(); }

	/** Called when a users host changes
	 * @param u The user
	 */
	virtual void OnSetDisplayedHost(User *) { throw NotImplementedException(); }

	/** Called when a memo is sent
	 * @param source The source of the memo
	 * @param target The target of the memo
	 * @param mi Memo info for target
	 * @param m The memo
	 */
	virtual void OnMemoSend(const Anope::string &source, const Anope::string &target, MemoInfo *mi, Memo *m) { throw NotImplementedException(); }

	/** Called when a memo is deleted
	 * @param target The target the memo is being deleted from (nick or channel)
	 * @param mi The memo info
	 * @param m The memo
	 */
	virtual void OnMemoDel(const Anope::string &target, MemoInfo *mi, const Memo *m) { throw NotImplementedException(); }

	/** Called when a mode is set on a channel
	 * @param c The channel
	 * @param setter The user or server that is setting the mode
	 * @param mode The mode
	 * @param param The mode param, if there is one
	 * @return EVENT_STOP to make mlock/secureops etc checks not happen
	 */
	virtual EventReturn OnChannelModeSet(Channel *c, MessageSource &setter, ChannelMode *mode, const Anope::string &param) { throw NotImplementedException(); }

	/** Called when a mode is unset on a channel
	 * @param c The channel
	 * @param setter The user or server that is unsetting the mode
	 * @param mode The mode
	 * @param param The mode param, if there is one
	 * @return EVENT_STOP to make mlock/secureops etc checks not happen
	 */
	virtual EventReturn OnChannelModeUnset(Channel *c, MessageSource &setter, ChannelMode *mode, const Anope::string &param) { throw NotImplementedException(); }

	/** Called when a mode is set on a user
	 * @param setter who/what is setting the mode
	 * @param u The user
	 * @param mname The mode name
	 */
	virtual void OnUserModeSet(const MessageSource &setter, User *u, const Anope::string &mname) { throw NotImplementedException(); }

	/** Called when a mode is unset from a user
	 * @param setter who/what is setting the mode
	 * @param u The user
	 * @param mname The mode name
	 */
	virtual void OnUserModeUnset(const MessageSource &setter, User *u, const Anope::string &mname) { throw NotImplementedException(); }

	/** Called when a channel mode is introduced into Anope
	 * @param cm The mode
	 */
	virtual void OnChannelModeAdd(ChannelMode *cm) { throw NotImplementedException(); }

	/** Called when a user mode is introduced into Anope
	 * @param um The mode
	 */
	virtual void OnUserModeAdd(UserMode *um) { throw NotImplementedException(); }

	/** Called when a mode is about to be mlocked
	 * @param ci The channel the mode is being locked on
	 * @param lock The mode lock
	 * @return EVENT_CONTINUE to let other modules decide, EVENT_STOP to deny the mlock.
	 */
	virtual EventReturn OnMLock(ChannelInfo *ci, ModeLock *lock) { throw NotImplementedException(); }

	/** Called when a mode is about to be unlocked
	 * @param ci The channel the mode is being unlocked from
	 * @param lock The mode lock
	 * @return EVENT_CONTINUE to let other modules decide, EVENT_STOP to deny the mlock.
	 */
	virtual EventReturn OnUnMLock(ChannelInfo *ci, ModeLock *lock) { throw NotImplementedException(); }

	/** Called after a module is loaded
	 * @param u The user loading the module, can be NULL
	 * @param m The module
	 */
	virtual void OnModuleLoad(User *u, Module *m) { throw NotImplementedException(); }

	/** Called before a module is unloaded
	 * @param u The user, can be NULL
	 * @param m The module
	 */
	virtual void OnModuleUnload(User *u, Module *m) { throw NotImplementedException(); }

	/** Called when a server is synced
	 * @param s The server, can be our uplink server
	 */
	virtual void OnServerSync(Server *s) { throw NotImplementedException(); }

	/** Called when we sync with our uplink
	 * @param s Our uplink
	 */
	virtual void OnUplinkSync(Server *s) { throw NotImplementedException(); }

	/** Called when we receive a PRIVMSG for one of our clients
	 * @param u The user sending the PRIVMSG
	 * @param bi The target of the PRIVMSG
	 * @param message The message
	 * @return EVENT_STOP to halt processing
	 */
	virtual EventReturn OnBotPrivmsg(User *u, BotInfo *bi, Anope::string &message) { throw NotImplementedException(); }

	/** Called when we receive a NOTICE for one of our clients
	 * @param u The user sending the NOTICE
	 * @param bi The target of the NOTICE
	 * @param message The message
	 */
	virtual void OnBotNotice(User *u, BotInfo *bi, Anope::string &message) { throw NotImplementedException(); }

	/** Called when we receive a PRIVMSG for a registered channel we are in
	 * @param u The source of the message
	 * @param c The channel
	 * @param msg The message
	 */
	virtual void OnPrivmsg(User *u, Channel *c, Anope::string &msg) { throw NotImplementedException(); }

	/** Called when a message is logged
	 * @param l The log message
	 */
	virtual void OnLog(Log *l) { throw NotImplementedException(); }

	/** Called when a log message is actually logged to a given log info
	 * The message has already passed validation checks by the LogInfo
	 * @param li The loginfo whee the message is being logged
	 * @param l The log message
	 * @param msg The final formatted message, derived from 'l'
	 */
	virtual void OnLogMessage(LogInfo *li, const Log *l, const Anope::string &msg) { throw NotImplementedException(); }

	/** Called when a DNS request (question) is received.
	 * @param req The dns request
	 * @param reply The reply that will be sent
	 */
	virtual void OnDnsRequest(DNS::Query &req, DNS::Query *reply) { throw NotImplementedException(); }

	/** Called when a channels modes are being checked to see if they are allowed,
	 * mostly to ensure mlock/+r are set.
	 * @param c The channel
	 */
	virtual void OnCheckModes(Reference<Channel> &c) { throw NotImplementedException(); }

	/** Called when a channel is synced.
	 * Channels are synced after a sjoin is finished processing
	 * for a newly created channel to set the correct modes, topic,
	 * set.
	 */
	virtual void OnChannelSync(Channel *c) { throw NotImplementedException(); }

	/** Called to set the correct modes on the user on the given channel
	 * @param user The user
	 * @param chan The channel
	 * @param access The user's access on the channel
	 * @param give_modes If giving modes is desired
	 * @param take_modes If taking modes is desired
	 */
	virtual void OnSetCorrectModes(User *user, Channel *chan, AccessGroup &access, bool &give_modes, bool &take_modes) { throw NotImplementedException(); }

	virtual void OnSerializeCheck(Serialize::Type *) { throw NotImplementedException(); }
	virtual void OnSerializableConstruct(Serializable *) { throw NotImplementedException(); }
	virtual void OnSerializableDestruct(Serializable *) { throw NotImplementedException(); }
	virtual void OnSerializableUpdate(Serializable *) { throw NotImplementedException(); }
	virtual void OnSerializeTypeCreate(Serialize::Type *) { throw NotImplementedException(); }

	/** Called when a chanserv/set command is used
	 * @param source The source of the command
	 * @param cmd The command
	 * @param ci The channel the command was used on
	 * @param setting The setting passed to the command. Probably ON/OFF.
	 * @return EVENT_ALLOW to bypass access checks, EVENT_STOP to halt immediately.
	 */
	virtual EventReturn OnSetChannelOption(CommandSource &source, Command *cmd, ChannelInfo *ci, const Anope::string &setting) { throw NotImplementedException(); }

	/** Called when a nickserv/set command is used.
	 * @param source The source of the command
	 * @param cmd The command
	 * @param nc The nickcore being modifed
	 * @param setting The setting passed to the command. Probably ON/OFF.
	 * @return EVENT_STOP to halt immediately
	 */
	virtual EventReturn OnSetNickOption(CommandSource &source, Command *cmd, NickCore *nc, const Anope::string &setting) { throw NotImplementedException(); }

	/** Called whenever a message is received from the uplink
	 * @param source The source of the message
	 * @param command The command being executed
	 * @param params Parameters
	 * @return EVENT_STOP to prevent the protocol module from processing this message
	 */
	virtual EventReturn OnMessage(MessageSource &source, Anope::string &command, std::vector<Anope::string> &param) { throw NotImplementedException(); }

	/** Called to determine if a channel mode can be set by a user
	 * @param u The user
	 * @param cm The mode
	 */
	virtual EventReturn OnCanSet(User *u, const ChannelMode *cm) { throw NotImplementedException(); }

	virtual EventReturn OnCheckDelete(Channel *) { throw NotImplementedException(); }

	/** Called every options:expiretimeout seconds. Should be used to expire nicks,
	 * channels, etc.
	 */
	virtual void OnExpireTick() { throw NotImplementedException(); }

	/** Called when a nick is validated. That is, to determine if a user is permitted
	 * to be on the given nick.
	 * @param u The user
	 * @param na The nick they are on
	 * @return EVENT_STOP to force the user off of the nick
	 */
	virtual EventReturn OnNickValidate(User *u, NickAlias *na) { throw NotImplementedException(); }

	/** Called when a certain user has to be unbanned on a certain channel.
	 * May be used to send protocol-specific messages.
	 * @param u The user to be unbanned
	 * @param c The channel that user has to be unbanned on
	 */
	virtual void OnChannelUnban(User *u, ChannelInfo *ci) { throw NotImplementedException(); }
};

enum Implementation
{
	I_OnPostInit,
	I_OnPreUserKicked, I_OnUserKicked, I_OnReload, I_OnPreBotAssign, I_OnBotAssign, I_OnBotUnAssign, I_OnUserConnect,
	I_OnNewServer, I_OnUserNickChange, I_OnPreHelp, I_OnPostHelp, I_OnPreCommand, I_OnPostCommand, I_OnSaveDatabase,
	I_OnLoadDatabase, I_OnEncrypt, I_OnDecrypt, I_OnBotFantasy, I_OnBotNoFantasyAccess, I_OnBotBan, I_OnBadWordAdd,
	I_OnBadWordDel, I_OnCreateBot, I_OnDelBot, I_OnBotKick, I_OnPrePartChannel, I_OnPartChannel, I_OnLeaveChannel,
	I_OnJoinChannel, I_OnTopicUpdated, I_OnPreChanExpire, I_OnChanExpire, I_OnPreServerConnect, I_OnServerConnect,
	I_OnPreUplinkSync, I_OnServerDisconnect, I_OnRestart, I_OnShutdown, I_OnPreNickExpire, I_OnNickExpire, I_OnDefconLevel,
	I_OnExceptionAdd, I_OnExceptionDel, I_OnAddXLine, I_OnDelXLine, I_IsServicesOper, I_OnServerQuit, I_OnUserQuit,
	I_OnPreUserLogoff, I_OnPostUserLogoff, I_OnBotCreate, I_OnBotChange, I_OnBotDelete, I_OnAccessDel, I_OnAccessAdd,
	I_OnAccessClear, I_OnLevelChange, I_OnChanDrop, I_OnChanRegistered, I_OnChanSuspend, I_OnChanUnsuspend,
	I_OnCreateChan, I_OnDelChan, I_OnChannelCreate, I_OnChannelDelete, I_OnAkickAdd, I_OnAkickDel, I_OnCheckKick,
	I_OnChanInfo, I_OnCheckPriv, I_OnGroupCheckPriv, I_OnNickDrop, I_OnNickGroup, I_OnNickIdentify,
	I_OnUserLogin, I_OnNickLogout, I_OnNickRegister, I_OnNickConfirm, I_OnNickSuspend, I_OnNickUnsuspended, I_OnDelNick, I_OnNickCoreCreate,
	I_OnDelCore, I_OnChangeCoreDisplay, I_OnNickClearAccess, I_OnNickAddAccess, I_OnNickEraseAccess, I_OnNickClearCert,
	I_OnNickAddCert, I_OnNickEraseCert, I_OnNickInfo, I_OnBotInfo, I_OnCheckAuthentication, I_OnNickUpdate,
	I_OnFingerprint, I_OnUserAway, I_OnInvite, I_OnDeleteVhost, I_OnSetVhost, I_OnSetDisplayedHost, I_OnMemoSend, I_OnMemoDel,
	I_OnChannelModeSet, I_OnChannelModeUnset, I_OnUserModeSet, I_OnUserModeUnset, I_OnChannelModeAdd, I_OnUserModeAdd,
	I_OnMLock, I_OnUnMLock, I_OnModuleLoad, I_OnModuleUnload, I_OnServerSync, I_OnUplinkSync, I_OnBotPrivmsg, I_OnBotNotice,
	I_OnPrivmsg, I_OnLog, I_OnLogMessage, I_OnDnsRequest, I_OnCheckModes, I_OnChannelSync, I_OnSetCorrectModes,
	I_OnSerializeCheck, I_OnSerializableConstruct, I_OnSerializableDestruct, I_OnSerializableUpdate,
	I_OnSerializeTypeCreate, I_OnSetChannelOption, I_OnSetNickOption, I_OnMessage, I_OnCanSet, I_OnCheckDelete,
	I_OnExpireTick, I_OnNickValidate, I_OnChannelUnban,
	I_SIZE
};

/** Used to manage modules.
 */
class CoreExport ModuleManager
{
 public:
	/** Event handler hooks.
	 */
	static std::vector<Module *> EventHandlers[I_SIZE];

	/** List of all modules loaded in Anope
	 */
	static std::list<Module *> Modules;

#ifdef _WIN32
	/** Clean up the module runtime directory
	 */
	static void CleanupRuntimeDirectory();
#endif

	/** Loads a given module.
	 * @param m the module to load
	 * @param u the user who loaded it, NULL for auto-load
	 * @return MOD_ERR_OK on success, anything else on fail
	 */
	static ModuleReturn LoadModule(const Anope::string &modname, User *u);

	/** Unload the given module.
	 * @param m the module to unload
	 * @param u the user who unloaded it
	 * @return MOD_ERR_OK on success, anything else on fail
	 */
	static ModuleReturn UnloadModule(Module *m, User * u);

	/** Find a module
	 * @param name The module name
	 * @return The module
	 */
	static Module *FindModule(const Anope::string &name);

	/** Find the first module of a certain type
	 * @param type The module type
	 * @return The module
	 */
	static Module *FindFirstOf(ModType type);

	/** Checks whether this version of Anope is at least major.minor.patch.build
	 * Throws a ModuleException if not
	 * @param major The major version
	 * @param minor The minor version
	 * @param patch The patch version
	 */
	static void RequireVersion(int major, int minor, int patch);

	/** Change the priority of one event in a module.
	 * Each module event has a list of modules which are attached to that event type. If you wish to be called before or after other specific modules, you may use this
	 * method (usually within void Module::Prioritize()) to set your events priority. You may use this call in other methods too, however, this is not supported behaviour
	 * for a module.
	 * @param mod The module to change the priority of
	 * @param i The event to change the priority of
	 * @param s The state you wish to use for this event. Use one of
	 * PRIO_FIRST to set the event to be first called, PRIO_LAST to set it to be the last called, or PRIO_BEFORE and PRIO_AFTER
	 * to set it to be before or after one or more other modules.
	 * @param modules If PRIO_BEFORE or PRIO_AFTER is set in parameter 's', then this contains a list of one or more modules your module must be
	 * placed before or after. Your module will be placed before the highest priority module in this list for PRIO_BEFORE, or after the lowest
	 * priority module in this list for PRIO_AFTER.
	 * @param sz The number of modules being passed for PRIO_BEFORE and PRIO_AFTER. Defaults to 1, as most of the time you will only want to prioritize your module
	 * to be before or after one other module.
	 */
	static bool SetPriority(Module *mod, Implementation i, Priority s, Module **modules = NULL, size_t sz = 1);

	/** Change the priority of all events in a module.
	 * @param mod The module to set the priority of
	 * @param s The priority of all events in the module.
	 * Note that with this method, it is not possible to effectively use PRIO_BEFORE or PRIO_AFTER, you should use the more fine tuned
	 * SetPriority method for this, where you may specify other modules to be prioritized against.
	 */
	static bool SetPriority(Module *mod, Priority s);

	/** Detach all events from a module (used on unload)
	 * @param mod Module to detach from
	 */
	static void DetachAll(Module *mod);

	/** Unloading all modules except the protocol module.
	 */
	static void UnloadAll();

 private:
	/** Call the module_delete function to safely delete the module
	 * @param m the module to delete
	 * @return MOD_ERR_OK on success, anything else on fail
	 */
	static ModuleReturn DeleteModule(Module *m);

	/** Get the version of Anope the module was compiled against
	 * @return The version
	 */
	static ModuleVersion GetVersion(void *handle);
};

#endif // MODULES_H
