/**

 * vim: set ts=4 :

 * =============================================================================

 * SourceMod

 * Copyright (C) 2004-2008 AlliedModders LLC.  All rights reserved.

 * =============================================================================

 *

 * This program is free software; you can redistribute it and/or modify it under

 * the terms of the GNU General Public License, version 3.0, as published by the

 * Free Software Foundation.

 * 

 * 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/>.

 *

 * As a special exception, AlliedModders LLC gives you permission to link the

 * code of this program (as well as its derivative works) to "Half-Life 2," the

 * "Source Engine," the "SourcePawn JIT," and any Game MODs that run on software

 * by the Valve Corporation.  You must obey the GNU General Public License in

 * all respects for all other code used.  Additionally, AlliedModders LLC grants

 * this exception to all derivative works.  AlliedModders LLC defines further

 * exceptions, found in LICENSE.txt (as of this writing, version JULY-31-2007),

 * or <http://www.sourcemod.net/license.php>.

 *

 * Version: $Id$

 */

#ifndef _INCLUDE_SOURCEMOD_ADMINISTRATION_SYSTEM_H_

#define _INCLUDE_SOURCEMOD_ADMINISTRATION_SYSTEM_H_

#include <IShareSys.h>

#define SMINTERFACE_ADMINSYS_NAME		"IAdminSys"

#define SMINTERFACE_ADMINSYS_VERSION	6

/**

 * @file IAdminSystem.h

 * @brief Defines the interface to manage the Admin Users/Groups and Override caches.

 *

 *   The administration system is more of a volatile cache than a system.  It is designed to be 

 * temporary rather than permanent, in order to compensate for more storage methods.  For example,

 * a flat file might be read into the cache all at once.  But a MySQL-based system might only cache

 * admin permissions when that specific admin connects.  

 *

 *   The override cache is the simplest to explain.  Any time an override is added, any existing 

 * and all future commands will gain a new access level set by the override.  If unset, the default

 * access level is restored.  This cache is dynamically changeable.

 *

 *   The group cache contains, for each group:

 *	1] A set of inherent flags - fully readable/writable.

 *  2] An immunity table - insertion and retrieval only.

 *  3] An override table - insertion and retrieval only.

 *   Individual groups can be invalidated entirely.  It should be considered an expensive

 *  operation, since each admin needs to be patched up to not reference the group.

 *

 *   For more information, see the SourceMod Development wiki.

 */

namespace SourceMod

{

	/**

	 * @brief Access levels (flags) for admins.

	 */

	enum AdminFlag

	{

		Admin_Reservation = 0,	/**< Reserved slot */

		Admin_Generic,			/**< Generic admin abilities */

		Admin_Kick,				/**< Kick another user */

		Admin_Ban,				/**< Ban another user */

		Admin_Unban,			/**< Unban another user */

		Admin_Slay,				/**< Slay/kill/damage another user */

		Admin_Changemap,		/**< Change the map */

		Admin_Convars,			/**< Change basic convars */

		Admin_Config,			/**< Change configuration */

		Admin_Chat,				/**< Special chat privileges */

		Admin_Vote,				/**< Special vote privileges */

		Admin_Password,			/**< Set a server password */

		Admin_RCON,				/**< Use RCON */

		Admin_Cheats,			/**< Change sv_cheats and use its commands */

		Admin_Root,				/**< All access by default */

		Admin_Custom1,			/**< First custom flag type */

		Admin_Custom2,			/**< Second custom flag type */

		Admin_Custom3,			/**< Third custom flag type */

		Admin_Custom4,			/**< Fourth custom flag type */

		Admin_Custom5,			/**< Fifth custom flag type */

		Admin_Custom6,			/**< Sixth custom flag type */

		/* --- */

		AdminFlags_TOTAL,

	};

	#define ADMFLAG_RESERVATION			(1<<0)		/**< Convenience macro for Admin_Reservation as a FlagBit */

	#define ADMFLAG_GENERIC				(1<<1)		/**< Convenience macro for Admin_Generic as a FlagBit */

	#define ADMFLAG_KICK				(1<<2)		/**< Convenience macro for Admin_Kick as a FlagBit */

	#define ADMFLAG_BAN					(1<<3)		/**< Convenience macro for Admin_Ban as a FlagBit */

	#define ADMFLAG_UNBAN				(1<<4)		/**< Convenience macro for Admin_Unban as a FlagBit */

	#define ADMFLAG_SLAY				(1<<5)		/**< Convenience macro for Admin_Slay as a FlagBit */

	#define ADMFLAG_CHANGEMAP			(1<<6)		/**< Convenience macro for Admin_Changemap as a FlagBit */

	#define ADMFLAG_CONVARS				(1<<7)		/**< Convenience macro for Admin_Convars as a FlagBit */

	#define ADMFLAG_CONFIG				(1<<8)		/**< Convenience macro for Admin_Config as a FlagBit */

	#define ADMFLAG_CHAT				(1<<9)		/**< Convenience macro for Admin_Chat as a FlagBit */

	#define ADMFLAG_VOTE				(1<<10)		/**< Convenience macro for Admin_Vote as a FlagBit */

	#define ADMFLAG_PASSWORD			(1<<11)		/**< Convenience macro for Admin_Password as a FlagBit */

	#define ADMFLAG_RCON				(1<<12)		/**< Convenience macro for Admin_RCON as a FlagBit */

	#define ADMFLAG_CHEATS				(1<<13)		/**< Convenience macro for Admin_Cheats as a FlagBit */

	#define ADMFLAG_ROOT				(1<<14)		/**< Convenience macro for Admin_Root as a FlagBit */

	#define ADMFLAG_CUSTOM1				(1<<15)		/**< Convenience macro for Admin_Custom1 as a FlagBit */

	#define ADMFLAG_CUSTOM2				(1<<16)		/**< Convenience macro for Admin_Custom2 as a FlagBit */

	#define ADMFLAG_CUSTOM3				(1<<17)		/**< Convenience macro for Admin_Custom3 as a FlagBit */

	#define ADMFLAG_CUSTOM4				(1<<18)		/**< Convenience macro for Admin_Custom4 as a FlagBit */

	#define ADMFLAG_CUSTOM5				(1<<19)		/**< Convenience macro for Admin_Custom5 as a FlagBit */

	#define ADMFLAG_CUSTOM6				(1<<20)		/**< Convenience macro for Admin_Custom6 as a FlagBit */

	/**

	 * @brief Specifies which type of command to override (command or command group).

	 */

	enum OverrideType

	{

		Override_Command = 1,	/**< Command */

		Override_CommandGroup,	/**< Command group */

	};

	/**

	 * @brief Specifies how a command is overridden for a user group.

	 */

	enum OverrideRule

	{

		Command_Deny = 0,		/**< Deny access */

		Command_Allow = 1,		/**< Allow access */

	};

	/**

	 * @brief DEPRECATED.  Specifies a generic immunity type.

	 */

	enum ImmunityType

	{

		Immunity_Default = 1,	/**< Immunity value of 1 */

		Immunity_Global,		/**< Immunity value of 2 */

	};

	/**

	 * @brief Defines user access modes.

	 */

	enum AccessMode

	{

		Access_Real,		/**< Access the user has inherently */

		Access_Effective,	/**< Access the user has from their groups */

	};

	/**

	 * @brief Represents an index to one group.

	 */

	typedef int		GroupId;

	/**

	 * @brief Represents an index to one user entry.

	 */

	typedef int		AdminId;

	/**

	 * @brief Represents an invalid/nonexistent group or an erroneous operation.

	 */

	#define INVALID_GROUP_ID	-1

	/**

	 * @brief Represents an invalid/nonexistent user or an erroneous operation.

	 */

	#define INVALID_ADMIN_ID	-1

	/**

	 * @brief Represents the various cache regions.

	 */

	enum AdminCachePart

	{

		AdminCache_Overrides = 0,		/**< Global overrides */

		AdminCache_Groups = 1,			/**< All groups (automatically invalidates admins too) */

		AdminCache_Admins = 2,			/**< All admins */

	};

	/**

	 * @brief Provides callbacks for admin cache operations.

	 */

	class IAdminListener

	{

	public:

		virtual unsigned int GetInterfaceVersion()

		{

			return SMINTERFACE_ADMINSYS_VERSION;

		}

	public:

		/**

		 * @brief Called when the admin cache needs to be rebuilt.  

		 *

		 * @param auto_rebuild		True if this is being called because of a group rebuild.

		 */

		virtual void OnRebuildAdminCache(bool auto_rebuild) =0;

		/**

		 * @brief Called when the group cache needs to be rebuilt.

		 */

		virtual void OnRebuildGroupCache() =0;

		/**

		 * @brief Called when the global override cache needs to be rebuilt.

		 */

		virtual void OnRebuildOverrideCache() =0;

	};

	/**

	 * @brief Admin permission levels.

	 */

	typedef unsigned int FlagBits;

	/**

	 * @brief Provides functions for manipulating the admin options cache.

	 */

	class IAdminSystem : public SMInterface

	{

	public:

		const char *GetInterfaceName()

		{

			return SMINTERFACE_ADMINSYS_NAME;

		}

		unsigned int GetInterfaceVersion()

		{

			return SMINTERFACE_ADMINSYS_VERSION;

		}

	public:

		/**

		 * @brief Adds a global command flag override.  Any command registered with this name

		 * will assume the new flag.  This is applied retroactively as well.

		 *

		 * @param cmd			String containing command name (case sensitive).

		 * @param type			Override type (specific command or group).

		 * @param flags			New admin flag.

		 */

		virtual void AddCommandOverride(const char *cmd, OverrideType type, FlagBits flags) =0;

		/**

		 * @brief Returns a command override.

		 *

		 * @param cmd			String containing command name (case sensitive).

		 * @param type			Override type (specific command or group).

		 * @param pFlags		Optional pointer to the set flag.

		 * @return				True if there is an override, false otherwise.

		 */

		virtual bool GetCommandOverride(const char *cmd, OverrideType type, FlagBits *pFlags) =0;

		/**

		 * @brief Unsets a command override.

		 *

		 * @param cmd			String containing command name (case sensitive).

		 * @param type			Override type (specific command or group).

		 */

		virtual void UnsetCommandOverride(const char *cmd, OverrideType type) =0;

		/**

		 * @brief Adds a new group.  Name must be unique.

		 *

		 * @param group_name	String containing the group name.

		 * @return				A new group id, INVALID_GROUP_ID if it already exists.

		 */

		virtual GroupId AddGroup(const char *group_name) =0;

		/**

		 * @brief Finds a group by name.

		 *

		 * @param group_name	String containing the group name.

		 * @return				A group id, or INVALID_GROUP_ID if not found.

		 */

		virtual GroupId FindGroupByName(const char *group_name) =0;

		/**

		 * @brief Adds or removes a flag from a group's flag set.

		 * Note: These are called "add flags" because they add to a user's flags.

		 *

		 * @param id			Group id.

		 * @param flag			Admin flag to toggle.

		 * @param enabled		True to set the flag, false to unset/disable.

		 */

		virtual void SetGroupAddFlag(GroupId id, AdminFlag flag, bool enabled) =0;

		/**

		 * @brief Gets the set value of an add flag on a group's flag set.

		 *

		 * @param id			Group id.

		 * @param flag			Admin flag to retrieve.

		 * @return				True if enabled, false otherwise,

		 */

		virtual bool GetGroupAddFlag(GroupId id, AdminFlag flag) =0;

		/**

		 * @brief Returns an array of flag bits that are added to a user from their group.

		 * Note: These are called "add flags" because they add to a user's flags.

		 *

		 * @param id			GroupId of the group.

		 * @return				Bit string containing the bits of each flag.

		 */

		virtual FlagBits GetGroupAddFlags(GroupId id) =0;

		/**

		 * @brief DEPRECATED.  Sets a group's immunity level using backwards 

		 * compatible types.  

		 *

		 * If the new level being set is lower than the group's actual immunity 

		 * level, no operation takes place.

		 *

		 * @param id			Group id.

		 * @param type			Immunity type which will be converted to a 

		 * 						numerical level.

		 * @param enabled		True to set the level.  False sets the 

		 * 						group's immunity value to 0.

		 */

		virtual void SetGroupGenericImmunity(GroupId id, ImmunityType type, bool enabled) =0;

		/**

		 * @brief DEPRECATED.  Returns whether a group has an immunity level

		 * using backwards compatible types.

		 * 

		 * This simply checks whether the group's immunity value is greater 

		 * than or equal to the new-style value for the old type.

		 *

		 * @param id			Group id.

		 * @param type			Generic immunity type.

		 * @return				True if the group has this immunity, false 

		 * 						otherwise.

		 */

		virtual bool GetGroupGenericImmunity(GroupId id, ImmunityType type) =0;

		/**

		 * @brief Adds immunity to a specific group.

		 *

		 * @param id			Group id.

		 * @param other_id		Group id to receive immunity to.

		 */

		virtual void AddGroupImmunity(GroupId id, GroupId other_id) =0;

		/**

		 * @brief Returns the number of specific group immunities.

		 *

		 * @param id			Group id.

		 * @return				Number of group immunities.

		 */

		virtual unsigned int GetGroupImmunityCount(GroupId id) =0;

		/**

		 * @brief Returns a group that this group is immune to given an index.

		 *

		 * @param id			Group id.

		 * @param number		Index from 0 to N-1, from GetGroupImmunities().

		 * @return				GroupId that this group is immune to.

		 */

		virtual GroupId GetGroupImmunity(GroupId id, unsigned int number) =0;

		/**

		 * @brief Adds a group-specific override type.

		 *

		 * @param id			Group id.

		 * @param name			String containing command name (case sensitive).

		 * @param type			Override type (specific command or group).

		 * @param rule			Override allow/deny setting.

		 */

		virtual void AddGroupCommandOverride(GroupId id,

											 const char *name,

											 OverrideType type,

											 OverrideRule rule) =0;

		/**

		 * @brief Retrieves a group-specific command override.

		 *

		 * @param id			Group id.

		 * @param name			String containing command name (case sensitive).

		 * @param type			Override type (specific command or group).

		 * @param pRule			Optional pointer to store allow/deny setting.

		 * @return				True if an override exists, false otherwise.

		 */

		virtual bool GetGroupCommandOverride(GroupId id,

											 const char *name,

											 OverrideType type,

											 OverrideRule *pRule) =0;

		/**

		 * @brief Tells the admin system to dump a portion of the cache.  

		 * This calls into plugin forwards to rebuild the cache.

		 *

		 * @param part			Portion of the cache to dump.

		 * @param rebuild		If true, the rebuild forwards/events will fire.

		 */

		virtual void DumpAdminCache(AdminCachePart part, bool rebuild) =0;

		/**

		 * @brief Adds an admin interface listener.

		 *

		 * @param pListener		Pointer to an IAdminListener to add.

		 */

		virtual void AddAdminListener(IAdminListener *pListener) =0;

		/**

		 * @brief Removes an admin interface listener.

		 *

		 * @param pListener		Pointer to an IAdminListener to remove.

		 */

		virtual void RemoveAdminListener(IAdminListener *pListener) =0;

		/**

		 * @brief Registers an authentication identity type.

		 * Note: Default types are "steam," "name," and "ip."

		 *

		 * @param name			String containing the type name.

		 */

		virtual void RegisterAuthIdentType(const char *name) =0;

		/**

		 * @brief Creates a new user entry.

		 *

		 * @param name		Name for this entry (does not have to be unique).

		 *					Specify NULL for an anonymous admin.

		 * @return			A new AdminId index.

		 */

		virtual AdminId CreateAdmin(const char *name) =0;

		/**

		 * @brief Gets an admin's user name.

		 *

		 * @param id		AdminId index for this admin.

		 * @return			A string containing the admin's name, or NULL

		 *					if the admin was created anonymously.

		 */

		virtual const char *GetAdminName(AdminId id) =0;

		/**

		 * @brief Binds a user entry to a particular auth method.

		 * This bind must be unique.

		 *

		 * @param id		AdminId index of the admin.

		 * @param auth		Auth method to use.

		 * @param ident		Identity string to bind to.

		 * @return			True on success, false if auth method was not found,

		 *					id was invalid, or ident was already taken.

		 */

		virtual bool BindAdminIdentity(AdminId id, const char *auth, const char *ident) =0;

		/**

		 * @brief Sets whether or not a flag is enabled on an admin.

		 *

		 * @param id		AdminId index of the admin.

		 * @param flag		Admin flag to use.

		 * @param enabled	True to enable, false to disable.

		 */

		virtual void SetAdminFlag(AdminId id, AdminFlag flag, bool enabled) =0;

		/**

		 * @brief Returns whether or not a flag is enabled on an admin.

		 *

		 * @param id		AdminId index of the admin.

		 * @param flag		Admin flag to use.

		 * @param mode		Access mode to check.

		 * @return			True if enabled, false otherwise.

		 */

		virtual bool GetAdminFlag(AdminId id, AdminFlag flag, AccessMode mode) =0;

		/**

		 * @brief Returns the bitstring of access flags on an admin.

		 *

		 * @param id		AdminId index of the admin.

		 * @param mode		Access mode to use.

		 * @return			A bit string containing which flags are enabled.

		 */

		virtual FlagBits GetAdminFlags(AdminId id, AccessMode mode) =0;

		/**

		 * @brief Sets the bitstring of access flags on an admin.

		 *

		 * @param id		AdminId index of the admin.

		 * @param mode		Access mode to use (real affects both).

		 * @param bits		Bitstring to set.

		 */

		virtual void SetAdminFlags(AdminId id, AccessMode mode, FlagBits bits) =0;

		/**

		 * @brief Adds a group to an admin's inherited group list.  

		 * Any flags the group has will be added to the admin's effective flags.

		 *

		 * @param id		AdminId index of the admin.

		 * @param gid		GroupId index of the group.

		 * @return			True on success, false on invalid input or duplicate membership.

		 */

		virtual bool AdminInheritGroup(AdminId id, GroupId gid) =0;

		/**

		 * @brief Returns the number of groups this admin is a member of.

		 * 

		 * @param id		AdminId index of the admin.

		 * @return			Number of groups this admin is a member of.

		 */

		virtual unsigned int GetAdminGroupCount(AdminId id) =0;

		/**

		 * @brief Returns group information from an admin.

		 *

		 * @param id		AdminId index of the admin.

		 * @param index		Group number to retrieve, from 0 to N-1, where N

		 *					is the value of GetAdminGroupCount(id).

		 * @param name		Optional pointer to store the group's name.

		 * @return			A GroupId index and a name pointer, or

		 *					INVALID_GROUP_ID and NULL if an error occurred.

		 */

		virtual GroupId GetAdminGroup(AdminId id, unsigned int index, const char **name) =0;

		/**

		 * @brief Sets a password on an admin.

		 *

		 * @param id		AdminId index of the admin.

		 * @param password	String containing the password.

		 */

		virtual void SetAdminPassword(AdminId id, const char *password) =0;

		/**

		 * @brief Gets an admin's password.

		 *

		 * @param id		AdminId index of the admin.

		 * @return			Password of the admin, or NULL if none.

		 */

		virtual const char *GetAdminPassword(AdminId id) =0;

		/**

		 * @brief Attempts to find an admin by an auth method and an identity.

		 *

		 * @param auth		Auth method to try.

		 * @param identity	Identity string to look up.

		 * @return			An AdminId index if found, INVALID_ADMIN_ID otherwise.

		 */

		virtual AdminId FindAdminByIdentity(const char *auth, const char *identity) =0;

		/**

		 * @brief Invalidates an admin from the cache so its resources can be re-used.

		 *

		 * @param id		AdminId index to invalidate.

		 * @return			True on success, false otherwise.

		 */

		virtual bool InvalidateAdmin(AdminId id) =0;

		/**

		 * @brief Converts a flag bit string to a bit array.

		 *

		 * @param bits		Bit string containing the flags.

		 * @param array		Array to write the flags to.  Enabled flags will be 'true'.

		 * @param maxSize	Maximum number of flags the array can store.

		 * @return			Number of flags written.

		 */

		virtual unsigned int FlagBitsToBitArray(FlagBits bits, bool array[], unsigned int maxSize) =0;

		/**

		 * @brief Converts a flag array to a bit string.

		 *

		 * @param array		Array containing true or false for each AdminFlag.

		 * @param maxSize	Maximum size of the flag array.

		 * @return			A bit string composed of the array bits.

		 */

		virtual FlagBits FlagBitArrayToBits(const bool array[], unsigned int maxSize) =0;

		/**

		 * @brief Converts an array of flags to bits.

		 *

		 * @param array		Array containing flags that are enabled.

		 * @param numFlags	Number of flags in the array.

		 * @return			A bit string composed of the array flags.

		 */

		virtual FlagBits FlagArrayToBits(const AdminFlag array[], unsigned int numFlags) =0;

		/**

		 * @brief Converts a bit string to an array of flags.

		 *

		 * @param bits		Bit string containing the flags.

		 * @param array		Output array to write flags.

		 * @param maxSize	Maximum size of the flag array.

		 * @return			Number of flags written.

		 */

		virtual unsigned int FlagBitsToArray(FlagBits bits, AdminFlag array[], unsigned int maxSize) =0;

		/**

		 * @brief Checks whether a user has access to a given set of flag bits.

		 * Note: This is a wrapper around GetAdminFlags().

		 *

		 * @param id		AdminId index of admin.

		 * @param bits		Bitstring containing the permissions to check.

		 * @return			True if user has permission, false otherwise.

		 */

		virtual bool CheckAdminFlags(AdminId id, FlagBits bits) =0;

		/**

		 * @brief Checks whether an AdminId can target another AdminId.

		 * 

		 * The hueristics for this check are as follows:

		 * 0. If the targeting AdminId is INVALID_ADMIN_ID, targeting fails.

		 * 1. If the targeted AdminId is INVALID_ADMIN_ID, targeting succeeds.

		 * 2. If the targeted AdminId is the same as the targeting AdminId,

		 *    (self) targeting succeeds.

		 * 3. If the targeting admin is root, targeting succeeds.

		 * 4. If the targeted admin has access higher (as interpreted by 

		 *    (sm_immunity_mode) than the targeting admin, then targeting fails.

		 * 5. If the targeted admin has specific immunity from the

		 *    targeting admin via group immunities, targeting fails.

		 * 6. Targeting succeeds.

		 *

		 * @param id		AdminId index of admin doing the targeting.  Can be INVALID_ADMIN_ID.

		 * @param target	AdminId index of the target admin.  Can be INVALID_ADMIN_ID.

		 * @return			True if this admin has permission to target the other admin.

		 */

		virtual bool CanAdminTarget(AdminId id, AdminId target) =0;

		/**

		 * @brief Returns a flag from a named string.

		 *

		 * @param flagname	Case sensitive flag name string (like "kick").

		 * @param pAdmFlag	Pointer to store the found admin flag in.

		 * @return			True on success, false on failure.

		 */

		virtual bool FindFlag(const char *flagname, AdminFlag *pAdmFlag) =0;

		/**

		 * @brief Reads a single character as a flag.

		 *

		 * @param c			Flag character.

		 * @param pAdmFlag	Pointer to store the admin flag.

		 * @return			True on success, false if invalid.

		 */

		virtual bool FindFlag(char c, AdminFlag *pAdmFlag) =0;

		/**

		 * @brief Reads a string of flag letters and returns its access value.

		 *

		 * @param flags		Flag string.

		 * @param end		Pointer to store the last value read.  On success, 

		 *					this will store a pointer to the null terminator.

		 * @return			FlagBits value of the flags.

		 */

		virtual FlagBits ReadFlagString(const char *flags, const char **end) =0;

		/**

		 * @brief Returns a "serial number" for an AdminId.  If the serial 

		 * number has changed for a given AdminId, it means the permissions 

		 * have changed.

		 *

		 * @param id		AdminId value.

		 * @return			Serial number, or 0 on failure.

		 */

		virtual unsigned int GetAdminSerialChange(AdminId id) =0;

		/**

		 * @brief Checks whether an admin can use the given command name.

		 *

		 * If the command does not exist, this will return true.

		 *

		 * @param client	Client index.

		 * @param cmd		Command name.

		 * @return			True on success, false on failure.

		 */

		virtual bool CanAdminUseCommand(int client, const char *cmd) =0;

		/**

		 * @brief Returns the name of a group.

		 *

		 * @param gid		Group Id.

		 * @return			Group name, or NULL on failure.

		 */

		virtual const char *GetGroupName(GroupId gid) =0;

		/**

		 * @brief Sets the immunity level of a group.

		 * 

		 * @param gid		Group Id.

		 * @param level		Immunity level value.

		 * @return			Old immunity level.

		 */

		virtual unsigned int SetGroupImmunityLevel(GroupId gid, unsigned int level) =0;

		/**

		 * @brief Retrieves the immunity level of a group.

		 *

		 * @param gid		Group Id.

		 * @return			Immunity level value.

		 */

		virtual unsigned int GetGroupImmunityLevel(GroupId gid) =0;

		/**

		 * @brief Sets the immunity level of an admin.

		 *

		 * @param id		Admin Id.

		 * @param level		Immunity level value.

		 * @return			Old immunity level.

		 */

		virtual unsigned int SetAdminImmunityLevel(AdminId id, unsigned int level) =0;

		/**

		 * @brief Retrieves the immunity level of an admin.

		 *

		 * @param id		Admin Id.

		 * @return			Immunity level value.

		 */

		virtual unsigned int GetAdminImmunityLevel(AdminId id) =0;

		/**

		 * @brief Computers access to an override.

		 *

		 * @param client		Client index.

		 * @param cmd			Override name.

		 * @param flags			Default flags.

		 * @param override_only	If false, if a command matches the override, 

		 *						then its flags will override the default.

		 * @return				True if the client has access, false otherwise.

		 */

		virtual bool CheckAccess(int client, 

			const char *cmd, 

			FlagBits flags, 

			bool override_only) =0;

		/**

		 * @brief Reads a flag as the corresponding character.

		 *

		 * @param flag		Flag to look up.

		 * @param c			Variable to store flag char.

		 * @return			True on success, false if not found.